From e164657a2b21cb2ab44eb073ed952f1ca9767e05 Mon Sep 17 00:00:00 2001
From: Rick Waldron <waldron.rick@gmail.com>
Date: Wed, 27 Jun 2018 12:58:02 -0400
Subject: [PATCH] Atomics: fixes to bigint variants; updated assertion messages

---
 test/built-ins/Atomics/Symbol.toStringTag.js  |   6 +-
 test/built-ins/Atomics/add/bad-range.js       |   6 +-
 .../built-ins/Atomics/add/bigint/bad-range.js |  11 +-
 .../Atomics/add/bigint/good-views.js          |  76 +++++-----
 .../Atomics/add/bigint/nonshared-int-views.js |  10 +-
 .../Atomics/add/expected-return-value.js      |   9 +-
 test/built-ins/Atomics/add/good-views.js      |  16 +-
 test/built-ins/Atomics/add/non-views.js       |   2 +-
 .../Atomics/add/nonshared-int-views.js        |   6 +-
 .../Atomics/add/shared-nonint-views.js        |   4 +-
 test/built-ins/Atomics/and/bad-range.js       |   8 +-
 .../built-ins/Atomics/and/bigint/bad-range.js |  13 +-
 .../Atomics/and/bigint/good-views.js          |  93 +++++++-----
 .../Atomics/and/bigint/nonshared-int-views.js |  10 +-
 .../Atomics/and/expected-return-value.js      |  21 +--
 test/built-ins/Atomics/and/good-views.js      |  24 +--
 test/built-ins/Atomics/and/non-views.js       |   2 +-
 .../Atomics/and/nonshared-int-views.js        |   6 +-
 .../Atomics/and/shared-nonint-views.js        |   4 +-
 .../Atomics/compareExchange/bad-range.js      |   8 +-
 .../compareExchange/bigint/bad-range.js       |  13 +-
 .../compareExchange/bigint/good-views.js      | 110 ++++++++------
 .../bigint/nonshared-int-views.js             |  10 +-
 .../compareExchange/expected-return-value.js  |   8 +-
 .../Atomics/compareExchange/good-views.js     |  18 +--
 .../Atomics/compareExchange/non-views.js      |   2 +-
 .../compareExchange/nonshared-int-views.js    |   2 +-
 .../compareExchange/shared-nonint-views.js    |   2 +-
 test/built-ins/Atomics/exchange/bad-range.js  |   8 +-
 .../Atomics/exchange/bigint/bad-range.js      |  11 +-
 .../Atomics/exchange/bigint/good-views.js     |  85 ++++++-----
 .../exchange/bigint/nonshared-int-views.js    |  10 +-
 .../Atomics/exchange/expected-return-value.js |   9 +-
 test/built-ins/Atomics/exchange/good-views.js |  18 +--
 test/built-ins/Atomics/exchange/non-views.js  |   2 +-
 .../Atomics/exchange/nonshared-int-views.js   |   2 +-
 .../Atomics/exchange/shared-nonint-views.js   |   2 +-
 .../Atomics/isLockFree/bigint/corner-cases.js |  52 ++++---
 .../bigint/expected-return-value.js           |   2 +-
 .../Atomics/isLockFree/corner-cases.js        |   8 +-
 .../isLockFree/expected-return-value.js       |  18 +--
 test/built-ins/Atomics/load/bad-range.js      |   2 +-
 .../Atomics/load/bigint/bad-range.js          |   4 +-
 .../Atomics/load/bigint/good-views.js         |  65 +++++----
 .../load/bigint/nonshared-int-views.js        |   4 +-
 .../Atomics/load/expected-return-value.js     |  15 +-
 test/built-ins/Atomics/load/good-views.js     |  18 +--
 test/built-ins/Atomics/load/non-views.js      |   2 +-
 .../Atomics/load/nonshared-int-views.js       |   9 +-
 .../Atomics/load/shared-nonint-views.js       |   4 +-
 test/built-ins/Atomics/or/bad-range.js        |   2 +-
 test/built-ins/Atomics/or/bigint/bad-range.js |  11 +-
 .../built-ins/Atomics/or/bigint/good-views.js | 131 +++++++++++------
 .../Atomics/or/bigint/nonshared-int-views.js  |  10 +-
 .../Atomics/or/expected-return-value.js       |  21 ++-
 test/built-ins/Atomics/or/good-views.js       |  42 ++++--
 test/built-ins/Atomics/or/non-views.js        |   2 +-
 .../Atomics/or/nonshared-int-views.js         |   6 +-
 .../Atomics/or/shared-nonint-views.js         |   2 +-
 test/built-ins/Atomics/prop-desc.js           |   6 +-
 test/built-ins/Atomics/proto.js               |   6 +-
 test/built-ins/Atomics/store/bad-range.js     |   8 +-
 .../Atomics/store/bigint/bad-range.js         |  13 +-
 .../Atomics/store/bigint/good-views.js        |  65 +++------
 .../store/bigint/nonshared-int-views.js       |  10 +-
 .../Atomics/store/expected-return-value.js    |  19 ++-
 test/built-ins/Atomics/store/good-views.js    |  20 ++-
 test/built-ins/Atomics/store/non-views.js     |   2 +-
 .../Atomics/store/nonshared-int-views.js      |   6 +-
 .../Atomics/store/shared-nonint-views.js      |   2 +-
 test/built-ins/Atomics/sub/bad-range.js       |   2 +-
 .../built-ins/Atomics/sub/bigint/bad-range.js |  13 +-
 .../Atomics/sub/bigint/good-views.js          |  82 ++++++-----
 .../Atomics/sub/bigint/nonshared-int-views.js |  10 +-
 .../Atomics/sub/expected-return-value.js      |  15 +-
 test/built-ins/Atomics/sub/good-views.js      |  16 +-
 test/built-ins/Atomics/sub/non-views.js       |   2 +-
 .../Atomics/sub/nonshared-int-views.js        |   6 +-
 .../Atomics/sub/shared-nonint-views.js        |   2 +-
 test/built-ins/Atomics/wait/bad-range.js      |   2 +-
 .../Atomics/wait/bigint/bad-range.js          |   4 +-
 .../wait/bigint/cannot-suspend-throws.js      |  10 +-
 .../wait/bigint/false-for-timeout-agent.js    |  30 ++--
 .../Atomics/wait/bigint/false-for-timeout.js  |  18 ++-
 .../Atomics/wait/bigint/good-views.js         |  49 -------
 .../Atomics/wait/bigint/nan-for-timeout.js    |   6 +-
 .../wait/bigint/negative-index-throws.js      |   8 +-
 .../wait/bigint/negative-timeout-agent.js     |   8 +-
 .../Atomics/wait/bigint/negative-timeout.js   |   6 +-
 .../bigint/no-spurious-wakeup-no-operation.js |  10 +-
 .../wait/bigint/no-spurious-wakeup-on-add.js  |  12 +-
 .../wait/bigint/no-spurious-wakeup-on-and.js  |  12 +-
 .../no-spurious-wakeup-on-compareExchange.js  |  12 +-
 .../bigint/no-spurious-wakeup-on-exchange.js  |  12 +-
 .../wait/bigint/no-spurious-wakeup-on-or.js   |  12 +-
 .../bigint/no-spurious-wakeup-on-store.js     |  12 +-
 .../wait/bigint/no-spurious-wakeup-on-sub.js  |  12 +-
 .../wait/bigint/no-spurious-wakeup-on-xor.js  |  12 +-
 .../bigint/non-bigint64-typedarray-throws.js  |   8 +-
 .../bigint/non-shared-bufferdata-throws.js    |   6 +-
 .../wait/bigint/null-bufferdata-throws.js     |   2 +-
 .../wait/bigint/out-of-range-index-throws.js  |   6 +-
 .../Atomics/wait/bigint/value-not-equal.js    |  18 ++-
 .../waiterlist-order-of-operations-is-fifo.js |  36 +++--
 .../wait/bigint/was-woken-before-timeout.js   |   8 +-
 .../Atomics/wait/cannot-suspend-throws.js     |   2 +-
 .../Atomics/wait/false-for-timeout-agent.js   |  24 ++-
 .../Atomics/wait/false-for-timeout.js         |  18 ++-
 test/built-ins/Atomics/wait/good-views.js     |  18 ++-
 .../built-ins/Atomics/wait/nan-for-timeout.js |   4 +-
 .../Atomics/wait/negative-index-throws.js     |   8 +-
 .../Atomics/wait/negative-timeout-agent.js    |   8 +-
 .../Atomics/wait/negative-timeout.js          |   6 +-
 .../Atomics/wait/no-spurious-wakeup-on-add.js |  10 +-
 .../Atomics/wait/no-spurious-wakeup-on-and.js |  10 +-
 .../no-spurious-wakeup-on-compareExchange.js  |  10 +-
 .../wait/no-spurious-wakeup-on-exchange.js    |  10 +-
 .../Atomics/wait/no-spurious-wakeup-on-or.js  |  10 +-
 .../wait/no-spurious-wakeup-on-store.js       |  10 +-
 .../Atomics/wait/no-spurious-wakeup-on-sub.js |  10 +-
 .../Atomics/wait/no-spurious-wakeup-on-xor.js |  10 +-
 .../wait/non-int32-typedarray-throws.js       |  16 +-
 .../wait/non-shared-bufferdata-throws.js      |   4 +-
 .../Atomics/wait/not-a-typedarray-throws.js   |   4 +-
 .../Atomics/wait/not-an-object-throws.js      |  14 +-
 .../Atomics/wait/null-bufferdata-throws.js    |   2 +-
 .../Atomics/wait/null-for-timeout-agent.js    |  24 ++-
 .../Atomics/wait/null-for-timeout.js          |  18 ++-
 .../Atomics/wait/object-for-timeout-agent.js  |  24 ++-
 .../Atomics/wait/object-for-timeout.js        |  18 ++-
 .../Atomics/wait/out-of-range-index-throws.js |   8 +-
 ...oisoned-object-for-timeout-throws-agent.js |  18 ++-
 .../poisoned-object-for-timeout-throws.js     |   4 +-
 .../wait/symbol-for-index-throws-agent.js     |  18 ++-
 .../Atomics/wait/symbol-for-index-throws.js   |   8 +-
 .../wait/symbol-for-timeout-throws-agent.js   |  18 ++-
 .../Atomics/wait/symbol-for-timeout-throws.js |   8 +-
 .../wait/symbol-for-value-throws-agent.js     |  18 ++-
 .../Atomics/wait/symbol-for-value-throws.js   |   8 +-
 .../Atomics/wait/true-for-timeout-agent.js    |  24 ++-
 .../Atomics/wait/true-for-timeout.js          |  18 ++-
 .../Atomics/wait/undefined-for-timeout.js     |  10 +-
 .../wait/undefined-index-defaults-to-zero.js  |   6 +-
 .../built-ins/Atomics/wait/value-not-equal.js |  12 +-
 .../wait/wait-index-value-not-equal.js        |  14 +-
 .../waiterlist-order-of-operations-is-fifo.js |  30 ++--
 .../Atomics/wait/was-woken-before-timeout.js  |   6 +-
 test/built-ins/Atomics/wake/bad-range.js      |   2 +-
 .../bigint/non-bigint64-typedarray-throws.js  |   4 +-
 .../bigint/non-shared-bufferdata-throws.js    |   4 +-
 .../wake/bigint/null-bufferdata-throws.js     |   2 +-
 .../Atomics/wake/bigint/wake-all-on-loc.js    |   2 +-
 .../Atomics/wake/count-boundary-cases.js      |   2 +-
 .../count-defaults-to-infinity-missing.js     |   2 +-
 .../count-defaults-to-infinity-undefined.js   |   2 +-
 .../wake/non-int32-typedarray-throws.js       |  16 +-
 ...hared-bufferdatate-non-shared-int-views.js |  12 +-
 .../Atomics/wake/non-shared-int-views.js      |  12 +-
 .../Atomics/wake/null-bufferdata-throws.js    |   2 +-
 .../built-ins/Atomics/wake/wake-all-on-loc.js |   2 +-
 test/built-ins/Atomics/wake/wake-all.js       |   2 +-
 .../Atomics/wake/wake-in-order-one-time.js    |  26 +++-
 test/built-ins/Atomics/wake/wake-in-order.js  |  26 +++-
 test/built-ins/Atomics/wake/wake-nan.js       |   2 +-
 test/built-ins/Atomics/wake/wake-one.js       |   2 +-
 .../Atomics/wake/wake-rewake-noop.js          |   2 +-
 test/built-ins/Atomics/wake/wake-two.js       |   2 +-
 test/built-ins/Atomics/wake/wake-zero.js      |   4 +-
 test/built-ins/Atomics/xor/bad-range.js       |   2 +-
 .../built-ins/Atomics/xor/bigint/bad-range.js |   2 +-
 .../Atomics/xor/bigint/good-views.js          | 137 ++++++++++++------
 .../Atomics/xor/bigint/nonshared-int-views.js |   2 +-
 .../Atomics/xor/expected-return-value.js      |  22 ++-
 test/built-ins/Atomics/xor/good-views.js      |  42 ++++--
 test/built-ins/Atomics/xor/non-views.js       |   2 +-
 .../Atomics/xor/nonshared-int-views.js        |   2 +-
 .../Atomics/xor/shared-nonint-views.js        |   2 +-
 177 files changed, 1517 insertions(+), 1059 deletions(-)
 delete mode 100644 test/built-ins/Atomics/wait/bigint/good-views.js

diff --git a/test/built-ins/Atomics/Symbol.toStringTag.js b/test/built-ins/Atomics/Symbol.toStringTag.js
index 83d8c5695c..5ae41be231 100644
--- a/test/built-ins/Atomics/Symbol.toStringTag.js
+++ b/test/built-ins/Atomics/Symbol.toStringTag.js
@@ -14,7 +14,11 @@ includes: [propertyHelper.js]
 features: [Atomics, Symbol, Symbol.toStringTag]
 ---*/
 
-assert.sameValue(Atomics[Symbol.toStringTag], 'Atomics');
+assert.sameValue(
+  Atomics[Symbol.toStringTag],
+  'Atomics',
+  'The value of Atomics[Symbol.toStringTag] is "Atomics"'
+);
 
 verifyNotEnumerable(Atomics, Symbol.toStringTag);
 verifyNotWritable(Atomics, Symbol.toStringTag);
diff --git a/test/built-ins/Atomics/add/bad-range.js b/test/built-ins/Atomics/add/bad-range.js
index fd02ea5ae3..e718c447c8 100644
--- a/test/built-ins/Atomics/add/bad-range.js
+++ b/test/built-ins/Atomics/add/bad-range.js
@@ -9,14 +9,14 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
-var views = intArrayConstructors.slice();
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   let view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.add(view, IdxGen(view), 10);
-    }, 'Atomics.add(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.add(view, IdxGen(view), 10)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/add/bigint/bad-range.js b/test/built-ins/Atomics/add/bigint/bad-range.js
index 2cc2155d67..50dbda674e 100644
--- a/test/built-ins/Atomics/add/bigint/bad-range.js
+++ b/test/built-ins/Atomics/add/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.add
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+var buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   let view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.add(view, IdxGen(view), 10);
-    }, 'Atomics.add(view, IdxGen(view), 10) throws RangeError');
+      Atomics.add(view, IdxGen(view), 10n);
+    }, '`Atomics.add(view, IdxGen(view), 10n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/add/bigint/good-views.js b/test/built-ins/Atomics/add/bigint/good-views.js
index c3781dbfc6..5af7ffad24 100644
--- a/test/built-ins/Atomics/add/bigint/good-views.js
+++ b/test/built-ins/Atomics/add/bigint/good-views.js
@@ -1,53 +1,53 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.add
 description: Test Atomics.add on arrays that allow atomic operations.
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  // Add positive number
-  view[8] = 0;
-  assert.sameValue(Atomics.add(view, 8, 10), 0, 'Atomics.add(view, 8, 10) returns 0');
-  assert.sameValue(view[8], 10, 'The value of view[8] is 10');
-
-  // Add negative number
-  assert.sameValue(Atomics.add(view, 8, -5), 10, 'Atomics.add(view, 8, -5) returns 10');
-  assert.sameValue(view[8], 5, 'The value of view[8] is 5');
-
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (-5)');
-
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (12345)');
-
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (123456789)');
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0n;
+  assert.sameValue(Atomics.add(view, 8, 10n), 0, 'Atomics.add(view, 8, 10n) returns 0');
+  assert.sameValue(view[8], 10n, 'The value of view[8] is 10n');
+  assert.sameValue(Atomics.add(view, 8, -5n), 10n, 'Atomics.add(view, 8, -5n) returns 10n');
+  assert.sameValue(view[8], 5n, 'The value of view[8] is 5n');
+  view[3] = -5n;
+  control[0] = -5n;
+
+  assert.sameValue(
+    Atomics.add(view, 3, 0n),
+    control[0],
+    'Atomics.add(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
+
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.add(view, 3, 0n),
+    control[0],
+    'Atomics.add(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.add(view, 3, 0n),
+    control[0],
+    'Atomics.add(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
     view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.add(view, Idx, 0), 37, 'Atomics.add(view, Idx, 0) returns 37');
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.add(view, Idx, 0), 37n, 'Atomics.add(view, Idx, 0) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/add/bigint/nonshared-int-views.js b/test/built-ins/Atomics/add/bigint/nonshared-int-views.js
index 72d796fd2e..1231021f15 100644
--- a/test/built-ins/Atomics/add/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/add/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.add
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var ab = new ArrayBuffer(16);
+var ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.add(new TA(ab), 0, 0);
-  }, 'Atomics.add(new TA(ab), 0, 0) throws TypeError');
-});
+    Atomics.add(new TA(ab), 0, 0n);
+  }, '`Atomics.add(new TA(ab), 0, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/add/expected-return-value.js b/test/built-ins/Atomics/add/expected-return-value.js
index 6de926e9b3..1840a92f7a 100644
--- a/test/built-ins/Atomics/add/expected-return-value.js
+++ b/test/built-ins/Atomics/add/expected-return-value.js
@@ -27,9 +27,10 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var newValue = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const newValue = 0b00000001000000001000000010000001;
 
 assert.sameValue(Atomics.add(i32a, 0, newValue), 0, 'Atomics.add(i32a, 0, newValue) returns 0');
-assert.sameValue(i32a[0], newValue, 'The value of i32a[0] equals the value of newValue (0b00000001000000001000000010000001)');
+assert.sameValue(i32a[0], newValue, 'The value of i32a[0] equals the value of `newValue` (0b00000001000000001000000010000001)');
diff --git a/test/built-ins/Atomics/add/good-views.js b/test/built-ins/Atomics/add/good-views.js
index 07731646be..9e047fbd4a 100644
--- a/test/built-ins/Atomics/add/good-views.js
+++ b/test/built-ins/Atomics/add/good-views.js
@@ -8,15 +8,15 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   // Add positive number
   view[8] = 0;
@@ -30,17 +30,17 @@ testWithTypedArrayConstructors(function(TA) {
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (-5)');
+    'Atomics.add(view, 3, 0) returns the value of `control[0]` (-5)');
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (12345)');
+    'Atomics.add(view, 3, 0) returns the value of `control[0]` (12345)');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.add(view, 3, 0), control[0],
-    'Atomics.add(view, 3, 0) equals the value of control[0] (123456789)');
+    'Atomics.add(view, 3, 0) returns the value of `control[0]` (123456789)');
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
diff --git a/test/built-ins/Atomics/add/non-views.js b/test/built-ins/Atomics/add/non-views.js
index 82711c52ab..6e5cbbd9a6 100644
--- a/test/built-ins/Atomics/add/non-views.js
+++ b/test/built-ins/Atomics/add/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.add(view, 0, 0);
-  }, 'Atomics.add(view, 0, 0) throws TypeError');
+  }, '`Atomics.add(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/add/nonshared-int-views.js b/test/built-ins/Atomics/add/nonshared-int-views.js
index b09f1b7c2f..fd90fa0054 100644
--- a/test/built-ins/Atomics/add/nonshared-int-views.js
+++ b/test/built-ins/Atomics/add/nonshared-int-views.js
@@ -9,11 +9,11 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.add(new TA(ab), 0, 0);
-  }, 'Atomics.add(new TA(ab), 0, 0) throws TypeError');
+  }, '`Atomics.add(new TA(ab), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/add/shared-nonint-views.js b/test/built-ins/Atomics/add/shared-nonint-views.js
index 505ea511c3..e3f05edf22 100644
--- a/test/built-ins/Atomics/add/shared-nonint-views.js
+++ b/test/built-ins/Atomics/add/shared-nonint-views.js
@@ -9,10 +9,10 @@ includes: [testTypedArray.js]
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(1024);
+const buffer = new SharedArrayBuffer(1024);
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.add(new TA(buffer), 0, 0);
-  }, 'Atomics.add(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.add(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
diff --git a/test/built-ins/Atomics/and/bad-range.js b/test/built-ins/Atomics/and/bad-range.js
index d44b4b4fbf..9bd37b2fbe 100644
--- a/test/built-ins/Atomics/and/bad-range.js
+++ b/test/built-ins/Atomics/and/bad-range.js
@@ -9,14 +9,14 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
-var views = intArrayConstructors.slice();
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.and(view, IdxGen(view), 10);
-    }, 'Atomics.and(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.and(view, IdxGen(view), 10)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/and/bigint/bad-range.js b/test/built-ins/Atomics/and/bigint/bad-range.js
index 6e688ed178..eb75e9c687 100644
--- a/test/built-ins/Atomics/and/bigint/bad-range.js
+++ b/test/built-ins/Atomics/and/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.and
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.and(view, IdxGen(view), 10);
-    }, 'Atomics.and(view, IdxGen(view), 10) throws RangeError');
+      Atomics.and(view, IdxGen(view), 10n);
+    }, '`Atomics.and(view, IdxGen(view), 10n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/and/bigint/good-views.js b/test/built-ins/Atomics/and/bigint/good-views.js
index 9f31e377a0..09cad2ce44 100644
--- a/test/built-ins/Atomics/and/bigint/good-views.js
+++ b/test/built-ins/Atomics/and/bigint/good-views.js
@@ -1,68 +1,83 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.and
 description: Test Atomics.and on arrays that allow atomic operations
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0x33333333n;
+  control[0] = 0x33333333n;
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  assert.sameValue(
+    Atomics.and(view, 8, 0x55555555n),
+    control[0],
+    'Atomics.and(view, 8, 0x55555555n) returns the value of `control[0]` (0x33333333n)'
+  );
 
-  view[8] = 0x33333333;
-  control[0] = 0x33333333;
-  assert.sameValue(Atomics.and(view, 8, 0x55555555), control[0],
-    'Atomics.and(view, 8, 0x55555555) equals the value of control[0] (0x33333333)');
+  control[0] = 0x11111111n;
 
-  control[0] = 0x11111111;
   assert.sameValue(
     view[8],
     control[0],
-    'The value of view[8] equals the value of control[0] (0x11111111)'
+    'The value of view[8] equals the value of `control[0]` (0x11111111n)'
+  );
+
+  assert.sameValue(
+    Atomics.and(view, 8, 0xF0F0F0F0n),
+    control[0],
+    'Atomics.and(view, 8, 0xF0F0F0F0n) returns the value of `control[0]` (0x11111111n)'
   );
-  assert.sameValue(Atomics.and(view, 8, 0xF0F0F0F0), control[0],
-    'Atomics.and(view, 8, 0xF0F0F0F0) equals the value of control[0] (0x11111111)');
 
-  control[0] = 0x10101010;
+  control[0] = 0x10101010n;
+
   assert.sameValue(
     view[8],
     control[0],
-    'The value of view[8] equals the value of control[0] (0x10101010)'
+    'The value of view[8] equals the value of `control[0]` (0x10101010n)'
   );
 
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (-5)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  view[3] = -5n;
+  control[0] = -5n;
 
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (12345)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  assert.sameValue(
+    Atomics.and(view, 3, 0n),
+    control[0],
+    'Atomics.and(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
+
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.and(view, 3, 0n),
+    control[0],
+    'Atomics.and(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.and(view, 3, 0n),
+    control[0],
+    'Atomics.and(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
 
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (123456789)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.and(view, Idx, 0), 37, 'Atomics.and(view, Idx, 0) returns 37');
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.and(view, Idx, 0n), 37n, 'Atomics.and(view, Idx, 0n) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/and/bigint/nonshared-int-views.js b/test/built-ins/Atomics/and/bigint/nonshared-int-views.js
index 17b270dc23..e4d86fbee4 100644
--- a/test/built-ins/Atomics/and/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/and/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.and
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+const buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.and(new TA(buffer), 0, 0);
-  }, 'Atomics.and(new TA(buffer), 0, 0) throws TypeError');
-});
+    Atomics.and(new TA(buffer), 0, 0n);
+  }, '`Atomics.and(new TA(buffer), 0, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/and/expected-return-value.js b/test/built-ins/Atomics/and/expected-return-value.js
index a9a9e5d30d..b587dfcb9a 100644
--- a/test/built-ins/Atomics/and/expected-return-value.js
+++ b/test/built-ins/Atomics/and/expected-return-value.js
@@ -27,18 +27,19 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var initial = 0b00000001000000001000000010000001;
-var other = 0b00000001111111111000000011111111;
-var anded = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const a = 0b00000001000000001000000010000001;
+const b = 0b00000001111111111000000011111111;
+const c = 0b00000001000000001000000010000001;
 
-i32a[0] = initial;
+i32a[0] = a;
 
 assert.sameValue(
-  Atomics.and(i32a, 0, other),
-  initial,
-  'Atomics.and(i32a, 0, other) equals the value of `initial` (0b00000001000000001000000010000001)'
+  Atomics.and(i32a, 0, b),
+  a,
+  'Atomics.and(i32a, 0, b) returns the value of `a` (0b00000001000000001000000010000001)'
 );
 
-assert.sameValue(i32a[0], anded, 'The value of i32a[0] equals the value of `anded` (0b00000001000000001000000010000001)');
+assert.sameValue(i32a[0], c, 'The value of i32a[0] equals the value of `c` (0b00000001000000001000000010000001)');
diff --git a/test/built-ins/Atomics/and/good-views.js b/test/built-ins/Atomics/and/good-views.js
index d6ec3fafbb..b1dee33d0f 100644
--- a/test/built-ins/Atomics/and/good-views.js
+++ b/test/built-ins/Atomics/and/good-views.js
@@ -8,53 +8,53 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   view[8] = 0x33333333;
   control[0] = 0x33333333;
   assert.sameValue(Atomics.and(view, 8, 0x55555555), control[0],
-    'Atomics.and(view, 8, 0x55555555) equals the value of control[0] (0x33333333)');
+    'Atomics.and(view, 8, 0x55555555) returns the value of `control[0]` (0x33333333)');
 
   control[0] = 0x11111111;
   assert.sameValue(
     view[8],
     control[0],
-    'The value of view[8] equals the value of control[0] (0x11111111)'
+    'The value of view[8] equals the value of `control[0]` (0x11111111)'
   );
   assert.sameValue(Atomics.and(view, 8, 0xF0F0F0F0), control[0],
-    'Atomics.and(view, 8, 0xF0F0F0F0) equals the value of control[0] (0x11111111)');
+    'Atomics.and(view, 8, 0xF0F0F0F0) returns the value of `control[0]` (0x11111111)');
 
   control[0] = 0x10101010;
   assert.sameValue(
     view[8],
     control[0],
-    'The value of view[8] equals the value of control[0] (0x10101010)'
+    'The value of view[8] equals the value of `control[0]` (0x10101010)'
   );
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (-5)');
+    'Atomics.and(view, 3, 0) returns the value of `control[0]` (-5)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (12345)');
+    'Atomics.and(view, 3, 0) returns the value of `control[0]` (12345)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.and(view, 3, 0), control[0],
-    'Atomics.and(view, 3, 0) equals the value of control[0] (123456789)');
+    'Atomics.and(view, 3, 0) returns the value of `control[0]` (123456789)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
   // In-bounds boundary cases for indexing
diff --git a/test/built-ins/Atomics/and/non-views.js b/test/built-ins/Atomics/and/non-views.js
index 45544aee28..4b50141d8f 100644
--- a/test/built-ins/Atomics/and/non-views.js
+++ b/test/built-ins/Atomics/and/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.and(view, 0, 0);
-  }, 'Atomics.and(view, 0, 0) throws TypeError');
+  }, '`Atomics.and(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/and/nonshared-int-views.js b/test/built-ins/Atomics/and/nonshared-int-views.js
index b578f411ac..ab37d61c98 100644
--- a/test/built-ins/Atomics/and/nonshared-int-views.js
+++ b/test/built-ins/Atomics/and/nonshared-int-views.js
@@ -9,11 +9,11 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var buffer = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const buffer = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.and(new TA(buffer), 0, 0);
-  }, 'Atomics.and(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.and(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/and/shared-nonint-views.js b/test/built-ins/Atomics/and/shared-nonint-views.js
index 3dbd81b3b8..2ba7884540 100644
--- a/test/built-ins/Atomics/and/shared-nonint-views.js
+++ b/test/built-ins/Atomics/and/shared-nonint-views.js
@@ -9,10 +9,10 @@ includes: [testTypedArray.js]
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(1024);
+const buffer = new SharedArrayBuffer(1024);
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.and(new TA(buffer), 0, 0);
-  }, 'Atomics.and(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.and(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
diff --git a/test/built-ins/Atomics/compareExchange/bad-range.js b/test/built-ins/Atomics/compareExchange/bad-range.js
index 9f1bcb0105..f4d007db27 100644
--- a/test/built-ins/Atomics/compareExchange/bad-range.js
+++ b/test/built-ins/Atomics/compareExchange/bad-range.js
@@ -9,14 +9,14 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
-var views = intArrayConstructors.slice();
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.compareExchange(view, IdxGen(view), 10, 0);
-    }, 'Atomics.compareExchange(view, IdxGen(view), 10, 0) throws RangeError');
+    }, '`Atomics.compareExchange(view, IdxGen(view), 10, 0)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/compareExchange/bigint/bad-range.js b/test/built-ins/Atomics/compareExchange/bigint/bad-range.js
index d28f9e861d..ed0929fd87 100644
--- a/test/built-ins/Atomics/compareExchange/bigint/bad-range.js
+++ b/test/built-ins/Atomics/compareExchange/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.compareexchange
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.compareExchange(view, IdxGen(view), 10, 0);
-    }, 'Atomics.compareExchange(view, IdxGen(view), 10, 0) throws RangeError');
+      Atomics.compareExchange(view, IdxGen(view), 10, 0n);
+    }, '`Atomics.compareExchange(view, IdxGen(view), 10, 0n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/compareExchange/bigint/good-views.js b/test/built-ins/Atomics/compareExchange/bigint/good-views.js
index af8c26c093..c954bd52ac 100644
--- a/test/built-ins/Atomics/compareExchange/bigint/good-views.js
+++ b/test/built-ins/Atomics/compareExchange/bigint/good-views.js
@@ -1,73 +1,91 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.compareexchange
 description: Test Atomics.compareExchange on arrays that allow atomic operations.
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0n;
+
+  assert.sameValue(
+    Atomics.compareExchange(view, 8, 0n, 10n),
+    0n,
+    'Atomics.compareExchange(view, 8, 0n, 10n) returns 0n'
+  );
+
+  assert.sameValue(view[8], 10n, 'The value of view[8] is 10n');
+  view[8] = 0n;
+
+  assert.sameValue(
+    Atomics.compareExchange(view, 8, 1n, 10n),
+    0n,
+    'Atomics.compareExchange(view, 8, 1n, 10n) returns 0n'
+  );
+
+  assert.sameValue(view[8], 0n, 'The value of view[8] is 0n');
+  view[8] = 0n;
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  assert.sameValue(
+    Atomics.compareExchange(view, 8, 0n, -5n),
+    0n,
+    'Atomics.compareExchange(view, 8, 0n, -5n) returns 0n'
+  );
+
+  control[0] = -5n;
 
-  // Performs the exchange
-  view[8] = 0;
   assert.sameValue(
-    Atomics.compareExchange(view, 8, 0, 10),
-    0,
-    'Atomics.compareExchange(view, 8, 0, 10) returns 0'
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (-5n)'
   );
-  assert.sameValue(view[8], 10, 'The value of view[8] is 10');
 
-  view[8] = 0;
-  assert.sameValue(Atomics.compareExchange(view, 8, 1, 10), 0,
-    'Atomics.compareExchange(view, 8, 1, 10) returns 0');
-  assert.sameValue(view[8], 0, 'The value of view[8] is 0');
+  view[3] = -5n;
+  control[0] = -5n;
 
-  view[8] = 0;
-  assert.sameValue(Atomics.compareExchange(view, 8, 0, -5), 0,
-    'Atomics.compareExchange(view, 8, 0, -5) returns 0');
-  control[0] = -5;
-  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of control[0] (-5)');
+  assert.sameValue(
+    Atomics.compareExchange(view, 3, -5n, 0n),
+    control[0],
+    'Atomics.compareExchange(view, 3, -5n, 0n) returns the value of `control[0]` (-5n)'
+  );
 
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
+  control[0] = 12345n;
+  view[3] = 12345n;
 
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.compareExchange(view, 3, -5, 0), control[0],
-    'Atomics.compareExchange(view, 3, -5, 0) equals the value of control[0] (-5)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  assert.sameValue(
+    Atomics.compareExchange(view, 3, 12345n, 0n),
+    control[0],
+    'Atomics.compareExchange(view, 3, 12345n, 0n) returns the value of `control[0]` (12345n)'
+  );
 
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
+  control[0] = 123456789n;
+  view[3] = 123456789n;
 
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.compareExchange(view, 3, 12345, 0), control[0],
-    'Atomics.compareExchange(view, 3, 12345, 0) equals the value of control[0] (12345)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  assert.sameValue(
+    Atomics.compareExchange(view, 3, 123456789n, 0n),
+    control[0],
+    'Atomics.compareExchange(view, 3, 123456789n, 0n) returns the value of `control[0]` (123456789n)'
+  );
 
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.compareExchange(view, 3, 123456789, 0), control[0],
-    'Atomics.compareExchange(view, 3, 123456789, 0) equals the value of control[0] (123456789)');
-  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+  assert.sameValue(view[3], 0n, 'The value of view[3] is 0n');
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+
     assert.sameValue(
-      Atomics.compareExchange(view, Idx, 37, 0),
-      37,
-      'Atomics.compareExchange(view, Idx, 37, 0) returns 37'
+      Atomics.compareExchange(view, Idx, 37n, 0n),
+      37n,
+      'Atomics.compareExchange(view, Idx, 37n, 0n) returns 37n'
     );
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/compareExchange/bigint/nonshared-int-views.js b/test/built-ins/Atomics/compareExchange/bigint/nonshared-int-views.js
index 5efe40c8e6..ad4cb89f10 100644
--- a/test/built-ins/Atomics/compareExchange/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/compareExchange/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.compareexchange
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+const buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.compareExchange(new TA(buffer), 0, 0, 0);
-  }, 'Atomics.compareExchange(new TA(buffer), 0, 0, 0) throws TypeError');
-});
+    Atomics.compareExchange(new TA(buffer), 0, 0n, 0n);
+  }, '`Atomics.compareExchange(new TA(buffer), 0, 0n, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/compareExchange/expected-return-value.js b/test/built-ins/Atomics/compareExchange/expected-return-value.js
index 5810279b14..9af90bae7b 100644
--- a/test/built-ins/Atomics/compareExchange/expected-return-value.js
+++ b/test/built-ins/Atomics/compareExchange/expected-return-value.js
@@ -26,15 +26,15 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
+const i32a = new Int32Array(buffer);
+const update = 0b00000001000000001000000010000001;
 
 i32a[0] = update;
 
 assert.sameValue(
   Atomics.compareExchange(i32a, 0, update, 0),
   update,
-  'Atomics.compareExchange(i32a, 0, update, 0) equals the value of update (0b00000001000000001000000010000001)'
+  'Atomics.compareExchange(i32a, 0, update, 0) returns the value of `update` (0b00000001000000001000000010000001)'
 );
 assert.sameValue(i32a[0], 0, 'The value of i32a[0] is 0');
diff --git a/test/built-ins/Atomics/compareExchange/good-views.js b/test/built-ins/Atomics/compareExchange/good-views.js
index 091414b496..bc9d29af7f 100644
--- a/test/built-ins/Atomics/compareExchange/good-views.js
+++ b/test/built-ins/Atomics/compareExchange/good-views.js
@@ -8,15 +8,15 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   // Performs the exchange
   view[8] = 0;
@@ -36,26 +36,26 @@ testWithTypedArrayConstructors(function(TA) {
   assert.sameValue(Atomics.compareExchange(view, 8, 0, -5), 0,
     'Atomics.compareExchange(view, 8, 0, -5) returns 0');
   control[0] = -5;
-  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of control[0] (-5)');
+  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of `control[0]` (-5)');
 
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.compareExchange(view, 3, -5, 0), control[0],
-    'Atomics.compareExchange(view, 3, -5, 0) equals the value of control[0] (-5)');
+    'Atomics.compareExchange(view, 3, -5, 0) returns the value of `control[0]` (-5)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.compareExchange(view, 3, 12345, 0), control[0],
-    'Atomics.compareExchange(view, 3, 12345, 0) equals the value of control[0] (12345)');
+    'Atomics.compareExchange(view, 3, 12345, 0) returns the value of `control[0]` (12345)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.compareExchange(view, 3, 123456789, 0), control[0],
-    'Atomics.compareExchange(view, 3, 123456789, 0) equals the value of control[0] (123456789)');
+    'Atomics.compareExchange(view, 3, 123456789, 0) returns the value of `control[0]` (123456789)');
   assert.sameValue(view[3], 0, 'The value of view[3] is 0');
 
   // In-bounds boundary cases for indexing
diff --git a/test/built-ins/Atomics/compareExchange/non-views.js b/test/built-ins/Atomics/compareExchange/non-views.js
index 2f49a21c90..f32827e594 100644
--- a/test/built-ins/Atomics/compareExchange/non-views.js
+++ b/test/built-ins/Atomics/compareExchange/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.compareExchange(view, 0, 0, 0);
-  }, 'Atomics.compareExchange(view, 0, 0, 0) throws TypeError');
+  }, '`Atomics.compareExchange(view, 0, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/compareExchange/nonshared-int-views.js b/test/built-ins/Atomics/compareExchange/nonshared-int-views.js
index d1477aa0be..2ffd28d66a 100644
--- a/test/built-ins/Atomics/compareExchange/nonshared-int-views.js
+++ b/test/built-ins/Atomics/compareExchange/nonshared-int-views.js
@@ -15,5 +15,5 @@ var views = intArrayConstructors.slice();
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.compareExchange(new TA(buffer), 0, 0, 0);
-  }, 'Atomics.compareExchange(new TA(buffer), 0, 0, 0) throws TypeError');
+  }, '`Atomics.compareExchange(new TA(buffer), 0, 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/compareExchange/shared-nonint-views.js b/test/built-ins/Atomics/compareExchange/shared-nonint-views.js
index 3160bc4419..e0590d6e8b 100644
--- a/test/built-ins/Atomics/compareExchange/shared-nonint-views.js
+++ b/test/built-ins/Atomics/compareExchange/shared-nonint-views.js
@@ -14,5 +14,5 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.compareExchange(new TA(buffer), 0, 0, 0);
-  }, 'Atomics.compareExchange(new TA(buffer), 0, 0, 0) throws TypeError');
+  }, '`Atomics.compareExchange(new TA(buffer), 0, 0, 0)` throws TypeError');
 }, floatArrayConstructors);
diff --git a/test/built-ins/Atomics/exchange/bad-range.js b/test/built-ins/Atomics/exchange/bad-range.js
index 80163b287f..330f3333cc 100644
--- a/test/built-ins/Atomics/exchange/bad-range.js
+++ b/test/built-ins/Atomics/exchange/bad-range.js
@@ -9,14 +9,14 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
-var views = intArrayConstructors.slice();
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.exchange(view, IdxGen(view), 10, 0);
-    }, 'Atomics.exchange(view, IdxGen(view), 10, 0) throws RangeError');
+    }, '`Atomics.exchange(view, IdxGen(view), 10, 0)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/exchange/bigint/bad-range.js b/test/built-ins/Atomics/exchange/bigint/bad-range.js
index 659d375970..b2326d0fa7 100644
--- a/test/built-ins/Atomics/exchange/bigint/bad-range.js
+++ b/test/built-ins/Atomics/exchange/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.exchange
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+var buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   let view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.exchange(view, IdxGen(view), 10, 0);
-    }, 'Atomics.exchange(view, IdxGen(view), 10, 0) throws RangeError');
+      Atomics.exchange(view, IdxGen(view), 10n, 0n);
+    }, '`Atomics.exchange(view, IdxGen(view), 10n, 0n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/exchange/bigint/good-views.js b/test/built-ins/Atomics/exchange/bigint/good-views.js
index cca30e8aeb..9c2cacc45b 100644
--- a/test/built-ins/Atomics/exchange/bigint/good-views.js
+++ b/test/built-ins/Atomics/exchange/bigint/good-views.js
@@ -1,54 +1,71 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.exchange
 description: Test Atomics.exchange on arrays that allow atomic operations.
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0n;
+  assert.sameValue(Atomics.exchange(view, 8, 10n), 0n, 'Atomics.exchange(view, 8, 10n) returns 0n');
+  assert.sameValue(view[8], 10n, 'The value of view[8] is 10n');
+
+  assert.sameValue(
+    Atomics.exchange(view, 8, -5n),
+    10n,
+    'Atomics.exchange(view, 8, -5n) returns 10n'
+  );
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  control[0] = -5n;
 
-  view[8] = 0;
-  assert.sameValue(Atomics.exchange(view, 8, 10), 0,
-    'Atomics.exchange(view, 8, 10) returns 0');
-  assert.sameValue(view[8], 10, 'The value of view[8] is 10');
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (-5n)'
+  );
 
-  assert.sameValue(Atomics.exchange(view, 8, -5), 10,
-    'Atomics.exchange(view, 8, -5) returns 10');
-  control[0] = -5;
-  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of control[0] (-5)');
+  view[3] = -5n;
+  control[0] = -5n;
 
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (-5)');
+  assert.sameValue(
+    Atomics.exchange(view, 3, 0n),
+    control[0],
+    'Atomics.exchange(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
 
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (12345)');
+  control[0] = 12345n;
+  view[3] = 12345n;
 
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (123456789)');
+  assert.sameValue(
+    Atomics.exchange(view, 3, 0n),
+    control[0],
+    'Atomics.exchange(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.exchange(view, 3, 0n),
+    control[0],
+    'Atomics.exchange(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.exchange(view, Idx, 0), 37, 'Atomics.exchange(view, Idx, 0) returns 37');
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+
+    assert.sameValue(
+      Atomics.exchange(view, Idx, 0n),
+      37n,
+      'Atomics.exchange(view, Idx, 0n) returns 37n'
+    );
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/exchange/bigint/nonshared-int-views.js b/test/built-ins/Atomics/exchange/bigint/nonshared-int-views.js
index 8a2d2a8259..c5fc8213b5 100644
--- a/test/built-ins/Atomics/exchange/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/exchange/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.exchange
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+var buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.exchange(new TA(buffer), 0, 0);
-  }, 'Atomics.exchange(new TA(buffer), 0, 0) throws TypeError');
-});
+    Atomics.exchange(new TA(buffer), 0n, 0n);
+  }, '`Atomics.exchange(new TA(buffer), 0n, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/exchange/expected-return-value.js b/test/built-ins/Atomics/exchange/expected-return-value.js
index 58eab15ef4..ef2e979928 100644
--- a/test/built-ins/Atomics/exchange/expected-return-value.js
+++ b/test/built-ins/Atomics/exchange/expected-return-value.js
@@ -27,9 +27,10 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const update = 0b00000001000000001000000010000001;
 
 assert.sameValue(
   Atomics.exchange(i32a, 0, update),
@@ -39,5 +40,5 @@ assert.sameValue(
 assert.sameValue(
   i32a[0],
   update,
-  'The value of i32a[0] equals the value of update (0b00000001000000001000000010000001)'
+  'The value of i32a[0] equals the value of `update` (0b00000001000000001000000010000001)'
 );
diff --git a/test/built-ins/Atomics/exchange/good-views.js b/test/built-ins/Atomics/exchange/good-views.js
index d0a21d455e..c3f63ab9e0 100644
--- a/test/built-ins/Atomics/exchange/good-views.js
+++ b/test/built-ins/Atomics/exchange/good-views.js
@@ -8,15 +8,15 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   view[8] = 0;
   assert.sameValue(Atomics.exchange(view, 8, 10), 0,
@@ -26,22 +26,22 @@ testWithTypedArrayConstructors(function(TA) {
   assert.sameValue(Atomics.exchange(view, 8, -5), 10,
     'Atomics.exchange(view, 8, -5) returns 10');
   control[0] = -5;
-  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of control[0] (-5)');
+  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of `control[0]` (-5)');
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (-5)');
+    'Atomics.exchange(view, 3, 0) returns the value of `control[0]` (-5)');
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (12345)');
+    'Atomics.exchange(view, 3, 0) returns the value of `control[0]` (12345)');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.exchange(view, 3, 0), control[0],
-    'Atomics.exchange(view, 3, 0) equals the value of control[0] (123456789)');
+    'Atomics.exchange(view, 3, 0) returns the value of `control[0]` (123456789)');
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
diff --git a/test/built-ins/Atomics/exchange/non-views.js b/test/built-ins/Atomics/exchange/non-views.js
index 02a899ec4f..20e1acda7e 100644
--- a/test/built-ins/Atomics/exchange/non-views.js
+++ b/test/built-ins/Atomics/exchange/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.exchange(view, 0, 0);
-  }, 'Atomics.exchange(view, 0, 0) throws TypeError');
+  }, '`Atomics.exchange(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/exchange/nonshared-int-views.js b/test/built-ins/Atomics/exchange/nonshared-int-views.js
index 8de5815f5f..f3514d1165 100644
--- a/test/built-ins/Atomics/exchange/nonshared-int-views.js
+++ b/test/built-ins/Atomics/exchange/nonshared-int-views.js
@@ -15,5 +15,5 @@ var views = intArrayConstructors.slice();
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.exchange(new TA(buffer), 0, 0);
-  }, 'Atomics.exchange(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.exchange(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/exchange/shared-nonint-views.js b/test/built-ins/Atomics/exchange/shared-nonint-views.js
index c3e4ad4d0a..371c9e191f 100644
--- a/test/built-ins/Atomics/exchange/shared-nonint-views.js
+++ b/test/built-ins/Atomics/exchange/shared-nonint-views.js
@@ -14,5 +14,5 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.exchange(new TA(buffer), 0, 0);
-  }, 'Atomics.exchange(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.exchange(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
diff --git a/test/built-ins/Atomics/isLockFree/bigint/corner-cases.js b/test/built-ins/Atomics/isLockFree/bigint/corner-cases.js
index ee48ff883c..51958fe100 100644
--- a/test/built-ins/Atomics/isLockFree/bigint/corner-cases.js
+++ b/test/built-ins/Atomics/isLockFree/bigint/corner-cases.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.islockfree
 description: >
@@ -8,22 +7,24 @@ description: >
 features: [arrow-function, Atomics, SharedArrayBuffer, ArrayBuffer, DataView, BigInt, let, TypedArray, for-of]
 includes: [testAtomics.js, testBigIntTypedArray.js]
 ---*/
-
 assert.sameValue(
   Atomics.isLockFree(hide(3, Number.NaN)),
   false,
   'Atomics.isLockFree(hide(3, Number.NaN)) returns false'
 );
+
 assert.sameValue(
   Atomics.isLockFree(hide(3, -1)),
   false,
   'Atomics.isLockFree(hide(3, -1)) returns false'
 );
+
 assert.sameValue(
   Atomics.isLockFree(hide(3, 3.14)),
   false,
   'Atomics.isLockFree(hide(3, 3.14)) returns false'
 );
+
 assert.sameValue(
   Atomics.isLockFree(hide(3, 0)),
   false,
@@ -33,12 +34,13 @@ assert.sameValue(
 assert.sameValue(
   Atomics.isLockFree('1'),
   Atomics.isLockFree(1),
-  'Atomics.isLockFree(\'1\') returns Atomics.isLockFree(1)'
+  'Atomics.isLockFree("1") returns Atomics.isLockFree(1)'
 );
+
 assert.sameValue(
   Atomics.isLockFree('3'),
   Atomics.isLockFree(3),
-  'Atomics.isLockFree(\'3\') returns Atomics.isLockFree(3)'
+  'Atomics.isLockFree("3") returns Atomics.isLockFree(3)'
 );
 
 assert.sameValue(
@@ -47,30 +49,26 @@ assert.sameValue(
   'Atomics.isLockFree(true) returns Atomics.isLockFree(1)'
 );
 
-assert.sameValue(
-  Atomics.isLockFree(1),
-  Atomics.isLockFree({valueOf: () => 1}),
-  'Atomics.isLockFree(1) returns Atomics.isLockFree({valueOf: () => 1})'
-);
-assert.sameValue(
-  Atomics.isLockFree(3),
-  Atomics.isLockFree({valueOf: () => 3}),
-  'Atomics.isLockFree(3) returns Atomics.isLockFree({valueOf: () => 3})'
-);
-assert.sameValue(
-  Atomics.isLockFree(1),
-  Atomics.isLockFree({toString: () => '1'}),
-  'Atomics.isLockFree(1) returns Atomics.isLockFree({toString: () => \'1\'})'
-);
-assert.sameValue(
-  Atomics.isLockFree(3),
-  Atomics.isLockFree({toString: () => '3'}),
-  'Atomics.isLockFree(3) returns Atomics.isLockFree({toString: () => \'3\'})'
-);
+assert.sameValue(Atomics.isLockFree(1), Atomics.isLockFree({
+  valueOf: () => 1
+}), 'Atomics.isLockFree(1) returns Atomics.isLockFree({\n    valueOf: () => 1\n})');
+
+assert.sameValue(Atomics.isLockFree(3), Atomics.isLockFree({
+  valueOf: () => 3
+}), 'Atomics.isLockFree(3) returns Atomics.isLockFree({\n    valueOf: () => 3\n})');
+
+assert.sameValue(Atomics.isLockFree(1), Atomics.isLockFree({
+  toString: () => '1'
+}), 'Atomics.isLockFree(1) returns Atomics.isLockFree({\n    toString: () => "1"\n})');
+
+assert.sameValue(Atomics.isLockFree(3), Atomics.isLockFree({
+  toString: () => '3'
+}), 'Atomics.isLockFree(3) returns Atomics.isLockFree({\n    toString: () => "3"\n})');
 
 function hide(k, x) {
   if (k) {
-    return hide(k - 3, x) + x;
+    return BigInt(hide(k - 3, x) + x);
   }
-  return 0;
-}
+
+  return 0n;
+}
\ No newline at end of file
diff --git a/test/built-ins/Atomics/isLockFree/bigint/expected-return-value.js b/test/built-ins/Atomics/isLockFree/bigint/expected-return-value.js
index 69cad37db6..b73f2901c8 100644
--- a/test/built-ins/Atomics/isLockFree/bigint/expected-return-value.js
+++ b/test/built-ins/Atomics/isLockFree/bigint/expected-return-value.js
@@ -28,7 +28,7 @@ testWithBigIntTypedArrayConstructors(function(TA) {
   assert.sameValue(
     Atomics.isLockFree(TA.BYTES_PER_ELEMENT),
     observed,
-    'Atomics.isLockFree(TA.BYTES_PER_ELEMENT) equals the value of `observed` (Atomics.isLockFree(TA.BYTES_PER_ELEMENT))'
+    'Atomics.isLockFree(TA.BYTES_PER_ELEMENT) returns the value of `observed` (Atomics.isLockFree(TA.BYTES_PER_ELEMENT))'
   );
 });
 
diff --git a/test/built-ins/Atomics/isLockFree/corner-cases.js b/test/built-ins/Atomics/isLockFree/corner-cases.js
index 8f77cda292..d4e713e8f3 100644
--- a/test/built-ins/Atomics/isLockFree/corner-cases.js
+++ b/test/built-ins/Atomics/isLockFree/corner-cases.js
@@ -32,12 +32,12 @@ assert.sameValue(
 assert.sameValue(
   Atomics.isLockFree('1'),
   Atomics.isLockFree(1),
-  'Atomics.isLockFree("1") returns Atomics.isLockFree(1)'
+  'Atomics.isLockFree(\'1\') returns Atomics.isLockFree(1)'
 );
 assert.sameValue(
   Atomics.isLockFree('3'),
   Atomics.isLockFree(3),
-  'Atomics.isLockFree("3") returns Atomics.isLockFree(3)'
+  'Atomics.isLockFree(\'3\') returns Atomics.isLockFree(3)'
 );
 
 assert.sameValue(
@@ -59,12 +59,12 @@ assert.sameValue(
 assert.sameValue(
   Atomics.isLockFree(1),
   Atomics.isLockFree({toString: () => '1'}),
-  'Atomics.isLockFree(1) returns Atomics.isLockFree({toString: () => "1"})'
+  'Atomics.isLockFree(1) returns Atomics.isLockFree({toString: () => \'1\'})'
 );
 assert.sameValue(
   Atomics.isLockFree(3),
   Atomics.isLockFree({toString: () => '3'}),
-  'Atomics.isLockFree(3) returns Atomics.isLockFree({toString: () => "3"})'
+  'Atomics.isLockFree(3) returns Atomics.isLockFree({toString: () => \'3\'})'
 );
 
 function hide(k, x) {
diff --git a/test/built-ins/Atomics/isLockFree/expected-return-value.js b/test/built-ins/Atomics/isLockFree/expected-return-value.js
index cd5795c784..72448c6576 100644
--- a/test/built-ins/Atomics/isLockFree/expected-return-value.js
+++ b/test/built-ins/Atomics/isLockFree/expected-return-value.js
@@ -32,7 +32,7 @@ var isLockFree8;
   assert.sameValue(
     Atomics.isLockFree(1),
     isLockFree1,
-    'Atomics.isLockFree(1) equals the value of `isLockFree1` (1)'
+    'Atomics.isLockFree(1) returns the value of `isLockFree1` (Atomics.isLockFree(1))'
   );
 };
 {
@@ -47,7 +47,7 @@ var isLockFree8;
   assert.sameValue(
     Atomics.isLockFree(2),
     isLockFree2,
-    'Atomics.isLockFree(2) equals the value of `isLockFree2` (2)'
+    'Atomics.isLockFree(2) returns the value of `isLockFree2` (Atomics.isLockFree(2))'
   );
 };
 {
@@ -55,8 +55,8 @@ var isLockFree8;
   //
   // If n equals 4, return true.
   //
-  assert.sameValue(typeof isLockFree4, 'boolean', 'The value of `typeof isLockFree` is "boolean"');
-  assert.sameValue(isLockFree4, true, 'The value of `isLockFree` is true');
+  assert.sameValue(typeof isLockFree4, 'boolean', 'The value of `typeof isLockFree4` is "boolean"');
+  assert.sameValue(isLockFree4, true, 'The value of `isLockFree4` is true');
 };
 
 {
@@ -71,14 +71,14 @@ var isLockFree8;
   assert.sameValue(
     Atomics.isLockFree(8),
     isLockFree8,
-    'Atomics.isLockFree(8) equals the value of `isLockFree8` (8)'
+    'Atomics.isLockFree(8) returns the value of `isLockFree8` (Atomics.isLockFree(8))'
   );
 };
 
 {
   for (let i = 0; i < 12; i++) {
     if (![1, 2, 4, 8].includes(i)) {
-      assert.sameValue(Atomics.isLockFree(i), false);
+      assert.sameValue(Atomics.isLockFree(i), false, 'Atomics.isLockFree(i) returns false');
     }
   }
 };
@@ -86,17 +86,17 @@ var isLockFree8;
 assert.sameValue(
   Atomics.isLockFree(1),
   isLockFree1,
-  'Later call to Atomics.isLockFree(1) equals the value of `isLockFree1` (1)'
+  'Atomics.isLockFree(1) returns the value of `isLockFree1` (Atomics.isLockFree(1))'
 );
 assert.sameValue(
   Atomics.isLockFree(2),
   isLockFree2,
-  'Later call to Atomics.isLockFree(2) equals the value of `isLockFree2` (2)'
+  'Atomics.isLockFree(2) returns the value of `isLockFree2` (Atomics.isLockFree(2))'
 );
 assert.sameValue(
   Atomics.isLockFree(8),
   isLockFree8,
-  'Later call to Atomics.isLockFree(8) equals the value of `isLockFree8` (8)'
+  'Atomics.isLockFree(8) returns the value of `isLockFree8` (Atomics.isLockFree(8))'
 );
 
 // Duplicates behavior created by loop from above
diff --git a/test/built-ins/Atomics/load/bad-range.js b/test/built-ins/Atomics/load/bad-range.js
index 14054e0dbc..c698ded175 100644
--- a/test/built-ins/Atomics/load/bad-range.js
+++ b/test/built-ins/Atomics/load/bad-range.js
@@ -17,6 +17,6 @@ testWithTypedArrayConstructors(function(TA) {
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.load(view, IdxGen(view));
-    }, 'Atomics.load(view, IdxGen(view)) throws RangeError');
+    }, '`Atomics.load(view, IdxGen(view))` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/load/bigint/bad-range.js b/test/built-ins/Atomics/load/bigint/bad-range.js
index 3f25785087..9da162b6a7 100644
--- a/test/built-ins/Atomics/load/bigint/bad-range.js
+++ b/test/built-ins/Atomics/load/bigint/bad-range.js
@@ -9,13 +9,13 @@ includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+var buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   let view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.load(view, IdxGen(view));
-    }, 'Atomics.load(view, IdxGen(view)) throws RangeError');
+    }, '`Atomics.load(view, IdxGen(view))` throws RangeError');
   });
 });
diff --git a/test/built-ins/Atomics/load/bigint/good-views.js b/test/built-ins/Atomics/load/bigint/good-views.js
index e044358c01..bc6824d133 100644
--- a/test/built-ins/Atomics/load/bigint/good-views.js
+++ b/test/built-ins/Atomics/load/bigint/good-views.js
@@ -1,45 +1,48 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.load
 description: Test Atomics.load on arrays that allow atomic operations.
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to coercion");
-
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to chopping");
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[3] = -5n;
+  control[0] = -5n;
+
+  assert.sameValue(
+    Atomics.load(view, 3),
+    control[0],
+    'Atomics.load(view, 3) returns the value of `control[0]` (-5n)'
+  );
+
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.load(view, 3),
+    control[0],
+    'Atomics.load(view, 3) returns the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.load(view, 3),
+    control[0],
+    'Atomics.load(view, 3) returns the value of `control[0]` (123456789n)'
+  );
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.load(view, Idx), 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.load(view, Idx), 37n, 'Atomics.load(view, Idx) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/load/bigint/nonshared-int-views.js b/test/built-ins/Atomics/load/bigint/nonshared-int-views.js
index 8dc6195901..949fb74596 100644
--- a/test/built-ins/Atomics/load/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/load/bigint/nonshared-int-views.js
@@ -9,7 +9,7 @@ includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
 
-var ab = new ArrayBuffer(16);
+var ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 
 testWithBigIntTypedArrayConstructors(function(TA) {
@@ -17,5 +17,5 @@ testWithBigIntTypedArrayConstructors(function(TA) {
 
   assert.throws(TypeError, function() {
     Atomics.load(view, 0);
-  }, 'Atomics.load(view, 0) throws TypeError');
+  }, '`Atomics.load(view, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/load/expected-return-value.js b/test/built-ins/Atomics/load/expected-return-value.js
index bc373f27a9..204d18058f 100644
--- a/test/built-ins/Atomics/load/expected-return-value.js
+++ b/test/built-ins/Atomics/load/expected-return-value.js
@@ -28,13 +28,18 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const update = 0b00000001000000001000000010000001;
 
-assert.sameValue(Atomics.load(i32a, 0), 0);
+assert.sameValue(Atomics.load(i32a, 0), 0, 'Atomics.load(i32a, 0) returns 0');
 
 i32a[0] = update;
 
-assert.sameValue(Atomics.load(i32a, 0), update);
+assert.sameValue(
+  Atomics.load(i32a, 0),
+  update,
+  'Atomics.load(i32a, 0) returns the value of `update` (0b00000001000000001000000010000001)'
+);
 
diff --git a/test/built-ins/Atomics/load/good-views.js b/test/built-ins/Atomics/load/good-views.js
index b36b892513..0f43410a51 100644
--- a/test/built-ins/Atomics/load/good-views.js
+++ b/test/built-ins/Atomics/load/good-views.js
@@ -8,31 +8,31 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
 
-var views = intArrayConstructors.slice();
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to coercion");
+    'Atomics.load(view, 3) returns the value of `control[0]` (-5)');
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to chopping");
+    'Atomics.load(view, 3) returns the value of `control[0]` (12345)');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.load(view, 3), control[0],
-    "Result is subject to chopping");
+    'Atomics.load(view, 3) returns the value of `control[0]` (123456789)');
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
@@ -41,6 +41,6 @@ testWithTypedArrayConstructors(function(TA) {
     // Atomics.store() computes an index from Idx in the same way as other
     // Atomics operations, not quite like view[Idx].
     Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.load(view, Idx), 37);
+    assert.sameValue(Atomics.load(view, Idx), 37, 'Atomics.load(view, Idx) returns 37');
   });
 }, views);
diff --git a/test/built-ins/Atomics/load/non-views.js b/test/built-ins/Atomics/load/non-views.js
index 2dab45f5da..ac9d0f57a7 100644
--- a/test/built-ins/Atomics/load/non-views.js
+++ b/test/built-ins/Atomics/load/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.load(view, 0);
-  }, 'Atomics.load(view, 0) throws TypeError');
+  }, '`Atomics.load(view, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/load/nonshared-int-views.js b/test/built-ins/Atomics/load/nonshared-int-views.js
index 6c33c02091..58f04ddc7a 100644
--- a/test/built-ins/Atomics/load/nonshared-int-views.js
+++ b/test/built-ins/Atomics/load/nonshared-int-views.js
@@ -9,14 +9,13 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var ab = new ArrayBuffer(16);
-
-var views = intArrayConstructors.slice();
+const buffer = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
-  var view = new TA(ab);
+  const view = new TA(buffer);
 
   assert.throws(TypeError, function() {
     Atomics.load(view, 0);
-  }, 'Atomics.load(view, 0) throws TypeError');
+  }, '`Atomics.load(view, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/load/shared-nonint-views.js b/test/built-ins/Atomics/load/shared-nonint-views.js
index 3e1f875a9d..ea493ccf82 100644
--- a/test/built-ins/Atomics/load/shared-nonint-views.js
+++ b/test/built-ins/Atomics/load/shared-nonint-views.js
@@ -9,9 +9,9 @@ includes: [testTypedArray.js]
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(1024);
+const buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.load(new TA(buffer), 0);
-  }, 'Atomics.load(new TA(buffer), 0) throws TypeError');
+  }, '`Atomics.load(new TA(buffer), 0)` throws TypeError');
 }, floatArrayConstructors);
diff --git a/test/built-ins/Atomics/or/bad-range.js b/test/built-ins/Atomics/or/bad-range.js
index 679eae4895..b3f94b5e34 100644
--- a/test/built-ins/Atomics/or/bad-range.js
+++ b/test/built-ins/Atomics/or/bad-range.js
@@ -17,6 +17,6 @@ testWithTypedArrayConstructors(function(TA) {
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.or(view, IdxGen(view), 10);
-    }, 'Atomics.or(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.or(view, IdxGen(view), 10)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/or/bigint/bad-range.js b/test/built-ins/Atomics/or/bigint/bad-range.js
index 81d866a55f..c8440e9b04 100644
--- a/test/built-ins/Atomics/or/bigint/bad-range.js
+++ b/test/built-ins/Atomics/or/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.or
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+var buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   let view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.or(view, IdxGen(view), 10);
-    }, 'Atomics.or(view, IdxGen(view), 10) throws RangeError');
+      Atomics.or(view, IdxGen(view), 10n);
+    }, '`Atomics.or(view, IdxGen(view), 10n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/or/bigint/good-views.js b/test/built-ins/Atomics/or/bigint/good-views.js
index 5c9afcf62a..fd882a3629 100644
--- a/test/built-ins/Atomics/or/bigint/good-views.js
+++ b/test/built-ins/Atomics/or/bigint/good-views.js
@@ -1,60 +1,97 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.or
 description: Test Atomics.or on arrays that allow atomic operations
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  view[8] = 0x33333333;
-  control[0] = 0x33333333;
-  assert.sameValue(Atomics.or(view, 8, 0x55555555), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 0x77777777;
-  assert.sameValue(view[8], control[0]);
-  assert.sameValue(Atomics.or(view, 8, 0xF0F0F0F0), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 0xF7F7F7F7;
-  assert.sameValue(view[8], control[0]);
-
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
-  assert.sameValue(view[3], control[0]);
-
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
-
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
-
-  // In-bounds boundary cases for indexing
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0x33333333n;
+  control[0] = 0x33333333n;
+
+  assert.sameValue(
+    Atomics.or(view, 8, 0x55555555n),
+    control[0],
+    'Atomics.or(view, 8, 0x55555555n) returns the value of `control[0]` (0x33333333n)'
+  );
+
+  control[0] = 0x77777777n;
+
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x77777777n)'
+  );
+
+  assert.sameValue(
+    Atomics.or(view, 8, 0xF0F0F0F0n),
+    control[0],
+    'Atomics.or(view, 8, 0xF0F0F0F0n) returns the value of `control[0]` (0x77777777n)'
+  );
+
+  control[0] = 0xF7F7F7F7n;
+
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0xF7F7F7F7n)'
+  );
+
+  view[3] = -5n;
+  control[0] = -5n;
+
+  assert.sameValue(
+    Atomics.or(view, 3, 0n),
+    control[0],
+    'Atomics.or(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (-5n)'
+  );
+
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.or(view, 3, 0n),
+    control[0],
+    'Atomics.or(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.or(view, 3, 0n),
+    control[0],
+    'Atomics.or(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (123456789n)'
+  );
+
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.or(view, Idx, 0), 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.or(view, Idx, 0n), 37n, 'Atomics.or(view, Idx, 0n) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/or/bigint/nonshared-int-views.js b/test/built-ins/Atomics/or/bigint/nonshared-int-views.js
index ae8b56117f..1dea6f2429 100644
--- a/test/built-ins/Atomics/or/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/or/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.or
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+const buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.or(new TA(buffer), 0, 0);
-  }, 'Atomics.or(new TA(buffer), 0, 0) throws TypeError');
-});
+    Atomics.or(new TA(buffer), 0, 0n);
+  }, '`Atomics.or(new TA(buffer), 0, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/or/expected-return-value.js b/test/built-ins/Atomics/or/expected-return-value.js
index 71971d2c85..9b560247eb 100644
--- a/test/built-ins/Atomics/or/expected-return-value.js
+++ b/test/built-ins/Atomics/or/expected-return-value.js
@@ -27,9 +27,20 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const a = 0b00000001000000001000000010000001;
+const b = 0b00000001111111111000000011111111;
+const c = 0b00000001111111111000000011111111;
+
+i32a[0] = a;
+
+assert.sameValue(
+  Atomics.or(i32a, 0, b),
+  a,
+  'Atomics.or(i32a, 0, b) returns the value of `a` (0b00000001000000001000000010000001)'
+);
+
+assert.sameValue(i32a[0], c, 'The value of i32a[0] equals the value of `c` (0b00000001111111111000000011111111)');
 
-assert.sameValue(Atomics.or(i32a, 0, update), 0);
-assert.sameValue(i32a[0], 0 | update);
diff --git a/test/built-ins/Atomics/or/good-views.js b/test/built-ins/Atomics/or/good-views.js
index 228500d69a..7522f1da43 100644
--- a/test/built-ins/Atomics/or/good-views.js
+++ b/test/built-ins/Atomics/or/good-views.js
@@ -21,33 +21,53 @@ testWithTypedArrayConstructors(function(TA) {
   view[8] = 0x33333333;
   control[0] = 0x33333333;
   assert.sameValue(Atomics.or(view, 8, 0x55555555), control[0],
-    "Result is subject to chopping");
+    'Atomics.or(view, 8, 0x55555555) returns the value of `control[0]` (0x33333333)');
 
   control[0] = 0x77777777;
-  assert.sameValue(view[8], control[0]);
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x77777777)'
+  );
   assert.sameValue(Atomics.or(view, 8, 0xF0F0F0F0), control[0],
-    "Result is subject to chopping");
+    'Atomics.or(view, 8, 0xF0F0F0F0) returns the value of `control[0]` (0x77777777)');
 
   control[0] = 0xF7F7F7F7;
-  assert.sameValue(view[8], control[0]);
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0xF7F7F7F7)'
+  );
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.or(view, 3, 0) returns the value of `control[0]` (-5)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (-5)'
+  );
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.or(view, 3, 0) returns the value of `control[0]` (12345)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (12345)'
+  );
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.or(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.or(view, 3, 0) returns the value of `control[0]` (123456789)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (123456789)'
+  );
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
@@ -56,6 +76,6 @@ testWithTypedArrayConstructors(function(TA) {
     // Atomics.store() computes an index from Idx in the same way as other
     // Atomics operations, not quite like view[Idx].
     Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.or(view, Idx, 0), 37);
+    assert.sameValue(Atomics.or(view, Idx, 0), 37, 'Atomics.or(view, Idx, 0) returns 37');
   });
 }, views);
diff --git a/test/built-ins/Atomics/or/non-views.js b/test/built-ins/Atomics/or/non-views.js
index 04f82bacfc..4cebf0f892 100644
--- a/test/built-ins/Atomics/or/non-views.js
+++ b/test/built-ins/Atomics/or/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.or(view, 0, 0);
-  }, 'Atomics.or(view, 0, 0) throws TypeError');
+  }, '`Atomics.or(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/or/nonshared-int-views.js b/test/built-ins/Atomics/or/nonshared-int-views.js
index 5c92bd5665..13d226697d 100644
--- a/test/built-ins/Atomics/or/nonshared-int-views.js
+++ b/test/built-ins/Atomics/or/nonshared-int-views.js
@@ -9,11 +9,11 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var buffer = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const buffer = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.or(new TA(buffer), 0, 0);
-  }, 'Atomics.or(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.or(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/or/shared-nonint-views.js b/test/built-ins/Atomics/or/shared-nonint-views.js
index 2dd48cbc3c..04ba84ab55 100644
--- a/test/built-ins/Atomics/or/shared-nonint-views.js
+++ b/test/built-ins/Atomics/or/shared-nonint-views.js
@@ -14,7 +14,7 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.or(new TA(buffer), 0, 0);
-  }, 'Atomics.or(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.or(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
 
 
diff --git a/test/built-ins/Atomics/prop-desc.js b/test/built-ins/Atomics/prop-desc.js
index 57cfb2ecba..90825f14f7 100644
--- a/test/built-ins/Atomics/prop-desc.js
+++ b/test/built-ins/Atomics/prop-desc.js
@@ -24,15 +24,15 @@ includes: [propertyHelper.js]
 features: [Atomics]
 ---*/
 
-assert.sameValue(typeof Atomics, "object");
+assert.sameValue(typeof Atomics, "object", 'The value of `typeof Atomics` is "object"');
 
 assert.throws(TypeError, function() {
   Atomics();
-}, "no [[Call]]");
+}, '`Atomics()` throws TypeError');
 
 assert.throws(TypeError, function() {
   new Atomics();
-}, "no [[Construct]]");
+}, '`new Atomics()` throws TypeError');
 
 verifyProperty(this, "Atomics", {
   enumerable: false,
diff --git a/test/built-ins/Atomics/proto.js b/test/built-ins/Atomics/proto.js
index 8072c47494..d6275cb56c 100644
--- a/test/built-ins/Atomics/proto.js
+++ b/test/built-ins/Atomics/proto.js
@@ -13,4 +13,8 @@ info: |
 features: [Atomics]
 ---*/
 
-assert.sameValue(Object.getPrototypeOf(Atomics), Object.prototype);
+assert.sameValue(
+  Object.getPrototypeOf(Atomics),
+  Object.prototype,
+  'Object.getPrototypeOf(Atomics) returns the value of `Object.prototype`'
+);
diff --git a/test/built-ins/Atomics/store/bad-range.js b/test/built-ins/Atomics/store/bad-range.js
index 224347fd36..fd26e25b82 100644
--- a/test/built-ins/Atomics/store/bad-range.js
+++ b/test/built-ins/Atomics/store/bad-range.js
@@ -9,14 +9,14 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
-var views = intArrayConstructors.slice();
+const buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.store(view, IdxGen(view), 10);
-    }, 'Atomics.store(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.store(view, IdxGen(view), 10)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/store/bigint/bad-range.js b/test/built-ins/Atomics/store/bigint/bad-range.js
index 38527f23c5..7cf5180359 100644
--- a/test/built-ins/Atomics/store/bigint/bad-range.js
+++ b/test/built-ins/Atomics/store/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.store
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.store(view, IdxGen(view), 10);
-    }, 'Atomics.store(view, IdxGen(view), 10) throws RangeError');
+      Atomics.store(view, IdxGen(view), 10n);
+    }, '`Atomics.store(view, IdxGen(view), 10n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/store/bigint/good-views.js b/test/built-ins/Atomics/store/bigint/good-views.js
index e6b27141f8..08b40f0f51 100644
--- a/test/built-ins/Atomics/store/bigint/good-views.js
+++ b/test/built-ins/Atomics/store/bigint/good-views.js
@@ -1,59 +1,42 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.store
 description: Test Atomics.store on arrays that allow atomic operations.
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+// Make it interesting - use non-zero byteOffsets and non-zero indexes.
+// In-bounds boundary cases for indexing
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  for (let val of [10, -5,
-      12345,
-      123456789,
-      Math.PI,
-      "33",
-      {
-        valueOf: () => 33
-      },
-      undefined
-    ])
-  {
-    assert.sameValue(Atomics.store(view, 3, val), ToInteger(val),
-      "Atomics.store returns its third argument (" + val + ") converted to Integer, not the input value nor the value that was stored");
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+
+  for (let val of [10n, -5n, 12345n, 123456789n, BigInt('33'), {
+    valueOf: () => 33n
+  }, BigInt(undefined)]) {
+    assert.sameValue(
+      Atomics.store(view, 3, val),
+      BigInt(val),
+      'Atomics.store(view, 3, val) returns BigInt(val)'
+    );
 
     control[0] = val;
-    assert.sameValue(view[3], control[0]);
+
+    assert.sameValue(
+      view[3],
+      control[0],
+      'The value of view[3] equals the value of `control[0]` (val)'
+    );
   }
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.load(view, Idx), 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.load(view, Idx), 37n, 'Atomics.load(view, Idx) returns 37n');
   });
 });
-
-function ToInteger(v) {
-  v = +v;
-  if (isNaN(v)) {
-    return 0;
-  }
-  if (v == 0 || !isFinite(v)) {
-    return v;
-  }
-  if (v < 0) {
-    return -Math.floor(Math.abs(v));
-  }
-  return Math.floor(v);
-}
diff --git a/test/built-ins/Atomics/store/bigint/nonshared-int-views.js b/test/built-ins/Atomics/store/bigint/nonshared-int-views.js
index ab5942d81b..b1999d514e 100644
--- a/test/built-ins/Atomics/store/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/store/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.store
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+const buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.store(new TA(buffer), 0, 0);
-  }, 'Atomics.store(new TA(buffer), 0, 0) throws TypeError');
-});
+    Atomics.store(new TA(buffer), 0, 0n);
+  }, '`Atomics.store(new TA(buffer), 0, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/store/expected-return-value.js b/test/built-ins/Atomics/store/expected-return-value.js
index 010886bbde..1ccff20c35 100644
--- a/test/built-ins/Atomics/store/expected-return-value.js
+++ b/test/built-ins/Atomics/store/expected-return-value.js
@@ -18,9 +18,18 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const update = 0b00000001000000001000000010000001;
 
-assert.sameValue(Atomics.store(i32a, 0, update), update);
-assert.sameValue(i32a[0], update);
+assert.sameValue(
+  Atomics.store(i32a, 0, update),
+  update,
+  'Atomics.store(i32a, 0, update) returns the value of `update` (0b00000001000000001000000010000001)'
+);
+assert.sameValue(
+  i32a[0],
+  update,
+  'The value of i32a[0] equals the value of `update` (0b00000001000000001000000010000001)'
+);
diff --git a/test/built-ins/Atomics/store/good-views.js b/test/built-ins/Atomics/store/good-views.js
index 4e665a7639..43a0c5f56f 100644
--- a/test/built-ins/Atomics/store/good-views.js
+++ b/test/built-ins/Atomics/store/good-views.js
@@ -8,15 +8,15 @@ includes: [testAtomics.js, testTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
 
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   // Make it interesting - use non-zero byteOffsets and non-zero indexes.
 
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
 
   for (let val of [10, -5,
       12345,
@@ -30,10 +30,14 @@ testWithTypedArrayConstructors(function(TA) {
     ])
   {
     assert.sameValue(Atomics.store(view, 3, val), ToInteger(val),
-      "Atomics.store returns its third argument (" + val + ") converted to Integer, not the input value nor the value that was stored");
+      'Atomics.store(view, 3, val) returns ToInteger(val)');
 
     control[0] = val;
-    assert.sameValue(view[3], control[0]);
+    assert.sameValue(
+      view[3],
+      control[0],
+      'The value of view[3] equals the value of `control[0]` (val)'
+    );
   }
 
   // In-bounds boundary cases for indexing
@@ -41,7 +45,7 @@ testWithTypedArrayConstructors(function(TA) {
     let Idx = IdxGen(view);
     view.fill(0);
     Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.load(view, Idx), 37);
+    assert.sameValue(Atomics.load(view, Idx), 37, 'Atomics.load(view, Idx) returns 37');
   });
 }, views);
 
diff --git a/test/built-ins/Atomics/store/non-views.js b/test/built-ins/Atomics/store/non-views.js
index bc256a3a27..aa0046aeaf 100644
--- a/test/built-ins/Atomics/store/non-views.js
+++ b/test/built-ins/Atomics/store/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.store(view, 0, 0);
-  }, 'Atomics.store(view, 0, 0) throws TypeError');
+  }, '`Atomics.store(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/store/nonshared-int-views.js b/test/built-ins/Atomics/store/nonshared-int-views.js
index 90591d4489..06541264d8 100644
--- a/test/built-ins/Atomics/store/nonshared-int-views.js
+++ b/test/built-ins/Atomics/store/nonshared-int-views.js
@@ -9,11 +9,11 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var buffer = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const buffer = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.store(new TA(buffer), 0, 0);
-  }, 'Atomics.store(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.store(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/store/shared-nonint-views.js b/test/built-ins/Atomics/store/shared-nonint-views.js
index fd3d159e89..acb7d8d880 100644
--- a/test/built-ins/Atomics/store/shared-nonint-views.js
+++ b/test/built-ins/Atomics/store/shared-nonint-views.js
@@ -14,7 +14,7 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.store(new TA(buffer), 0, 0);
-  }, 'Atomics.store(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.store(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
 
 
diff --git a/test/built-ins/Atomics/sub/bad-range.js b/test/built-ins/Atomics/sub/bad-range.js
index 6d9871bb9d..e041a78748 100644
--- a/test/built-ins/Atomics/sub/bad-range.js
+++ b/test/built-ins/Atomics/sub/bad-range.js
@@ -17,6 +17,6 @@ testWithTypedArrayConstructors(function(TA) {
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.sub(view, IdxGen(view), 10);
-    }, 'Atomics.sub(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.sub(view, IdxGen(view), 10)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/sub/bigint/bad-range.js b/test/built-ins/Atomics/sub/bigint/bad-range.js
index d033c212e0..9ca736812f 100644
--- a/test/built-ins/Atomics/sub/bigint/bad-range.js
+++ b/test/built-ins/Atomics/sub/bigint/bad-range.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.sub
 description: >
@@ -8,14 +7,14 @@ description: >
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 2);
+const buffer = new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  let view = new TA(buffer);
+  const view = new TA(buffer);
+
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
-      Atomics.sub(view, IdxGen(view), 10);
-    }, 'Atomics.sub(view, IdxGen(view), 10) throws RangeError');
+      Atomics.sub(view, IdxGen(view), 10n);
+    }, '`Atomics.sub(view, IdxGen(view), 10n)` throws RangeError');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/sub/bigint/good-views.js b/test/built-ins/Atomics/sub/bigint/good-views.js
index ca79f54086..676dd8b5c3 100644
--- a/test/built-ins/Atomics/sub/bigint/good-views.js
+++ b/test/built-ins/Atomics/sub/bigint/good-views.js
@@ -1,53 +1,57 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.sub
 description: Test Atomics.sub on arrays that allow atomic operations
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+// Make it interesting - use non-zero byteOffsets and non-zero indexes.
+// In-bounds boundary cases for indexing
+// Atomics.store() computes an index from Idx in the same way as other
+// Atomics operations, not quite like view[Idx].
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  view[8] = 100;
-  assert.sameValue(Atomics.sub(view, 8, 10), 100,
-    "Subtract positive number");
-  assert.sameValue(view[8], 90);
-
-  assert.sameValue(Atomics.sub(view, 8, -5), 90,
-    "Subtract negative number, though result remains positive");
-  assert.sameValue(view[8], 95);
-
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
-
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is subject to chopping");
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 100n;
+  assert.sameValue(Atomics.sub(view, 8, 10n), 100n, 'Atomics.sub(view, 8, 10n) returns 100n');
+  assert.sameValue(view[8], 90n, 'The value of view[8] is 90n');
+  assert.sameValue(Atomics.sub(view, 8, -5n), 90n, 'Atomics.sub(view, 8, -5n) returns 90n');
+  assert.sameValue(view[8], 95, 'The value of view[8] is 95');
+  view[3] = -5n;
+  control[0] = -5n;
+
+  assert.sameValue(
+    Atomics.sub(view, 3, 0n),
+    control[0],
+    'Atomics.sub(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
+
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.sub(view, 3, 0n),
+    control[0],
+    'Atomics.sub(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.sub(view, 3, 0n),
+    control[0],
+    'Atomics.sub(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
 
-  // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.sub(view, Idx, 0), 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.sub(view, Idx, 0n), 37n, 'Atomics.sub(view, Idx, 0n) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/sub/bigint/nonshared-int-views.js b/test/built-ins/Atomics/sub/bigint/nonshared-int-views.js
index de1455b301..58274797df 100644
--- a/test/built-ins/Atomics/sub/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/sub/bigint/nonshared-int-views.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.sub
 description: >
@@ -8,11 +7,10 @@ description: >
 includes: [testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, TypedArray]
 ---*/
-
-var buffer = new ArrayBuffer(16);
+const buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 2);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
-    Atomics.sub(new TA(buffer), 0, 0);
-  }, 'Atomics.sub(new TA(buffer), 0, 0) throws TypeError');
-});
+    Atomics.sub(new TA(buffer), 0, 0n);
+  }, '`Atomics.sub(new TA(buffer), 0, 0n)` throws TypeError');
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/sub/expected-return-value.js b/test/built-ins/Atomics/sub/expected-return-value.js
index eb0fcf88ba..c4d1d1bf6e 100644
--- a/test/built-ins/Atomics/sub/expected-return-value.js
+++ b/test/built-ins/Atomics/sub/expected-return-value.js
@@ -27,11 +27,16 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var update = 0b00000001000000001000000010000001;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const update = 0b00000001000000001000000010000001;
 
 i32a[0] = update;
 
-assert.sameValue(Atomics.sub(i32a, 0, update), update);
-assert.sameValue(i32a[0], 0);
+assert.sameValue(
+  Atomics.sub(i32a, 0, update),
+  update,
+  'Atomics.sub(i32a, 0, update) returns the value of `update` (0b00000001000000001000000010000001)'
+);
+assert.sameValue(i32a[0], 0, 'The value of i32a[0] is 0');
diff --git a/test/built-ins/Atomics/sub/good-views.js b/test/built-ins/Atomics/sub/good-views.js
index 411e1ad185..e05c6720c2 100644
--- a/test/built-ins/Atomics/sub/good-views.js
+++ b/test/built-ins/Atomics/sub/good-views.js
@@ -20,27 +20,27 @@ testWithTypedArrayConstructors(function(TA) {
 
   view[8] = 100;
   assert.sameValue(Atomics.sub(view, 8, 10), 100,
-    "Subtract positive number");
-  assert.sameValue(view[8], 90);
+    'Atomics.sub(view, 8, 10) returns 100');
+  assert.sameValue(view[8], 90, 'The value of view[8] is 90');
 
   assert.sameValue(Atomics.sub(view, 8, -5), 90,
-    "Subtract negative number, though result remains positive");
-  assert.sameValue(view[8], 95);
+    'Atomics.sub(view, 8, -5) returns 90');
+  assert.sameValue(view[8], 95, 'The value of view[8] is 95');
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
+    'Atomics.sub(view, 3, 0) returns the value of `control[0]` (-5)');
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is subject to chopping");
+    'Atomics.sub(view, 3, 0) returns the value of `control[0]` (12345)');
 
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.sub(view, 3, 0), control[0],
-    "Result is subject to chopping");
+    'Atomics.sub(view, 3, 0) returns the value of `control[0]` (123456789)');
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
@@ -49,6 +49,6 @@ testWithTypedArrayConstructors(function(TA) {
     // Atomics.store() computes an index from Idx in the same way as other
     // Atomics operations, not quite like view[Idx].
     Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.sub(view, Idx, 0), 37);
+    assert.sameValue(Atomics.sub(view, Idx, 0), 37, 'Atomics.sub(view, Idx, 0) returns 37');
   });
 }, views);
diff --git a/test/built-ins/Atomics/sub/non-views.js b/test/built-ins/Atomics/sub/non-views.js
index 46233994e6..695f021863 100644
--- a/test/built-ins/Atomics/sub/non-views.js
+++ b/test/built-ins/Atomics/sub/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.sub(view, 0, 0);
-  }, 'Atomics.sub(view, 0, 0) throws TypeError');
+  }, '`Atomics.sub(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/sub/nonshared-int-views.js b/test/built-ins/Atomics/sub/nonshared-int-views.js
index ff7bbf0925..b3f6c74a1c 100644
--- a/test/built-ins/Atomics/sub/nonshared-int-views.js
+++ b/test/built-ins/Atomics/sub/nonshared-int-views.js
@@ -9,11 +9,11 @@ includes: [testTypedArray.js]
 features: [ArrayBuffer, Atomics, TypedArray]
 ---*/
 
-var buffer = new ArrayBuffer(16);
-var views = intArrayConstructors.slice();
+const buffer = new ArrayBuffer(16);
+const views = intArrayConstructors.slice();
 
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.sub(new TA(buffer), 0, 0);
-  }, 'Atomics.sub(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.sub(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/sub/shared-nonint-views.js b/test/built-ins/Atomics/sub/shared-nonint-views.js
index 9c373891cf..599f77f413 100644
--- a/test/built-ins/Atomics/sub/shared-nonint-views.js
+++ b/test/built-ins/Atomics/sub/shared-nonint-views.js
@@ -14,7 +14,7 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.sub(new TA(buffer), 0, 0);
-  }, 'Atomics.sub(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.sub(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
 
 
diff --git a/test/built-ins/Atomics/wait/bad-range.js b/test/built-ins/Atomics/wait/bad-range.js
index 8299a66f0f..607149e6b4 100644
--- a/test/built-ins/Atomics/wait/bad-range.js
+++ b/test/built-ins/Atomics/wait/bad-range.js
@@ -22,5 +22,5 @@ const i32a = new Int32Array(
 testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
   assert.throws(RangeError, function() {
     Atomics.wait(i32a, IdxGen(i32a), 0, 0);
-  }, 'Atomics.wait(i32a, IdxGen(i32a), 0, 0) throws RangeError');
+  }, '`Atomics.wait(i32a, IdxGen(i32a), 0, 0)` throws RangeError');
 });
diff --git a/test/built-ins/Atomics/wait/bigint/bad-range.js b/test/built-ins/Atomics/wait/bigint/bad-range.js
index 4a942951ae..ae0644e618 100644
--- a/test/built-ins/Atomics/wait/bigint/bad-range.js
+++ b/test/built-ins/Atomics/wait/bigint/bad-range.js
@@ -21,6 +21,6 @@ const i64a = new BigInt64Array(
 
 testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
   assert.throws(RangeError, function() {
-    Atomics.wait(i64a, IdxGen(i64a), 0, 0);
-  }, 'Atomics.wait(i64a, IdxGen(i64a), 0, 0) throws RangeError');
+    Atomics.wait(i64a, IdxGen(i64a), 0n, 0);
+  }, '`Atomics.wait(i64a, IdxGen(i64a), 0n, 0)` throws RangeError');
 });
diff --git a/test/built-ins/Atomics/wait/bigint/cannot-suspend-throws.js b/test/built-ins/Atomics/wait/bigint/cannot-suspend-throws.js
index 08b6551bb8..05ad9aba09 100644
--- a/test/built-ins/Atomics/wait/bigint/cannot-suspend-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/cannot-suspend-throws.js
@@ -1,6 +1,5 @@
 // Copyright (C) 2018 Amal Hussein. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.wait
 description: >
@@ -17,11 +16,8 @@ info: |
 features: [Atomics, BigInt, SharedArrayBuffer, TypedArray]
 flags: [CanBlockIsFalse]
 ---*/
-
-const i64a = new BigInt64Array(
-  new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 8)
-);
+const i64a = new BigInt64Array(new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 8));
 
 assert.throws(TypeError, function() {
-  Atomics.wait(i64a, 0, 0, 0);
-});
+  Atomics.wait(i64a, 0, 0n, 0);
+}, '`Atomics.wait(i64a, 0, 0n, 0)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/bigint/false-for-timeout-agent.js b/test/built-ins/Atomics/wait/bigint/false-for-timeout-agent.js
index 9ed38e8987..54732a390b 100644
--- a/test/built-ins/Atomics/wait/bigint/false-for-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/bigint/false-for-timeout-agent.js
@@ -32,9 +32,9 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    $262.agent.report(Atomics.wait(i64a, 0, 0, false));
-    $262.agent.report(Atomics.wait(i64a, 0, 0, valueOf));
-    $262.agent.report(Atomics.wait(i64a, 0, 0, toPrimitive));
+    $262.agent.report(Atomics.wait(i64a, 0, 0n, false));
+    $262.agent.report(Atomics.wait(i64a, 0, 0n, valueOf));
+    $262.agent.report(Atomics.wait(i64a, 0, 0n, toPrimitive));
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.leaving();
   });
@@ -47,18 +47,30 @@ const i64a = new BigInt64Array(
 $262.agent.broadcast(i64a.buffer);
 $262.agent.sleep(100);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
 
 const lapse = $262.agent.getReport();
 assert(
   lapse >= 0,
-  `${lapse} should be greater than, or equal to 0`
+  'The result of `(lapse >= 0)` is true'
 );
 assert(
   lapse <= $262.agent.MAX_TIME_EPSILON,
-  `${lapse} should be less than ${$262.agent.MAX_TIME_EPSILON}`
+  'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true'
 );
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/bigint/false-for-timeout.js b/test/built-ins/Atomics/wait/bigint/false-for-timeout.js
index 2188167e54..b16ac53274 100644
--- a/test/built-ins/Atomics/wait/bigint/false-for-timeout.js
+++ b/test/built-ins/Atomics/wait/bigint/false-for-timeout.js
@@ -32,7 +32,19 @@ const toPrimitive = {
   }
 };
 
-assert.sameValue(Atomics.wait(i64a, 0, 0, false), "timed-out");
-assert.sameValue(Atomics.wait(i64a, 0, 0, valueOf), "timed-out");
-assert.sameValue(Atomics.wait(i64a, 0, 0, toPrimitive), "timed-out");
+assert.sameValue(
+  Atomics.wait(i64a, 0, 0n, false),
+  "timed-out",
+  'Atomics.wait(i64a, 0, 0n, false) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i64a, 0, 0n, valueOf),
+  "timed-out",
+  'Atomics.wait(i64a, 0, 0n, valueOf) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i64a, 0, 0n, toPrimitive),
+  "timed-out",
+  'Atomics.wait(i64a, 0, 0n, toPrimitive) returns "timed-out"'
+);
 
diff --git a/test/built-ins/Atomics/wait/bigint/good-views.js b/test/built-ins/Atomics/wait/bigint/good-views.js
deleted file mode 100644
index 0c1bbc0ca8..0000000000
--- a/test/built-ins/Atomics/wait/bigint/good-views.js
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright (C) 2018 Rick Waldron. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-atomics.wait
-description: >
-  Test Atomics.wait on arrays that allow atomic operations,
-  in an Agent that is allowed to wait.
-includes: [atomicsHelper.js]
-features: [Atomics, BigInt]
----*/
-
-// Let's assume 'wait' is not allowed on the main thread,
-// even in the shell.
-
-$262.agent.start(`
-  const sab = new SharedArrayBuffer(1024);
-  const ab = new ArrayBuffer(16);
-
-  const good_indices = [ (view) => 0/-1, // -0
-                       (view) => '-0',
-                       (view) => view.length - 1,
-                       (view) => ({ valueOf: () => 0 }),
-                       (view) => ({ toString: () => '0', valueOf: false }) // non-callable valueOf triggers invocation of toString
-                     ];
-
-  const view = new BigInt64Array(sab, 32, 20);
-
-  view[0] = 0;
-  $262.agent.report("A " + Atomics.wait(view, 0, 0, 0))
-  $262.agent.report("B " + Atomics.wait(view, 0, 37, 0));
-
-  // In-bounds boundary cases for indexing
-  for ( let IdxGen of good_indices ) {
-    let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    $262.agent.report("C " + Atomics.wait(view, Idx, 0));
-  }
-
-  $262.agent.report("done");
-  $262.agent.leaving();
-`);
-
-assert.sameValue($262.agent.getReport(), 'A timed-out');
-assert.sameValue($262.agent.getReport(), 'B not-equal');
-assert.sameValue($262.agent.getReport(), 'C not-equal');
diff --git a/test/built-ins/Atomics/wait/bigint/nan-for-timeout.js b/test/built-ins/Atomics/wait/bigint/nan-for-timeout.js
index 21723c9bec..04c8343fe3 100644
--- a/test/built-ins/Atomics/wait/bigint/nan-for-timeout.js
+++ b/test/built-ins/Atomics/wait/bigint/nan-for-timeout.js
@@ -20,7 +20,7 @@ features: [Atomics, BigInt, SharedArrayBuffer, TypedArray]
 $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
-    $262.agent.report(Atomics.wait(i64a, 0, 0, NaN));  // NaN => +Infinity
+    $262.agent.report(Atomics.wait(i64a, 0, 0n, NaN));  // NaN => +Infinity
     $262.agent.leaving();
   });
 `);
@@ -31,5 +31,5 @@ const i64a = new BigInt64Array(
 
 $262.agent.broadcast(i64a.buffer);
 $262.agent.sleep(100);
-assert.sameValue(Atomics.wake(i64a, 0), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
+assert.sameValue(Atomics.wake(i64a, 0), 1, 'Atomics.wake(i64a, 0) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
diff --git a/test/built-ins/Atomics/wait/bigint/negative-index-throws.js b/test/built-ins/Atomics/wait/bigint/negative-index-throws.js
index 9acd86db1e..552b710478 100644
--- a/test/built-ins/Atomics/wait/bigint/negative-index-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/negative-index-throws.js
@@ -27,13 +27,13 @@ const poisoned = {
 
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, -Infinity, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, -Infinity, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, -7.999, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, -7.999, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, -1, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, -1, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, -300, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, -300, poisoned, poisoned)` throws RangeError');
diff --git a/test/built-ins/Atomics/wait/bigint/negative-timeout-agent.js b/test/built-ins/Atomics/wait/bigint/negative-timeout-agent.js
index d828c990c9..d46bc8b691 100644
--- a/test/built-ins/Atomics/wait/bigint/negative-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/bigint/negative-timeout-agent.js
@@ -23,5 +23,9 @@ const i64a = new BigInt64Array(
 
 $262.agent.broadcast(i64a.buffer);
 $262.agent.sleep(10);
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/bigint/negative-timeout.js b/test/built-ins/Atomics/wait/bigint/negative-timeout.js
index a3239d9ce0..35bc0d57f6 100644
--- a/test/built-ins/Atomics/wait/bigint/negative-timeout.js
+++ b/test/built-ins/Atomics/wait/bigint/negative-timeout.js
@@ -13,4 +13,8 @@ const i64a = new BigInt64Array(
   new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 8)
 );
 
-assert.sameValue(Atomics.wait(i64a, 0, 0, -1), "timed-out");
+assert.sameValue(
+  Atomics.wait(i64a, 0, 0n, -1),
+  "timed-out",
+  'Atomics.wait(i64a, 0, 0n, -1) returns "timed-out"'
+);
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-no-operation.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-no-operation.js
index cb91b6da4e..221668f83d 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-no-operation.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-no-operation.js
@@ -40,7 +40,11 @@ $262.agent.sleep(10);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-add.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-add.js
index 2cc3ddae5f..7e223b6b04 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-add.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-add.js
@@ -18,7 +18,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -33,9 +33,13 @@ Atomics.add(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-and.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-and.js
index 2d92ce6f43..5352f006bf 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-and.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-and.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,9 +32,13 @@ Atomics.and(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-compareExchange.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-compareExchange.js
index b6faecf477..3b36acc82c 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-compareExchange.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-compareExchange.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,7 +32,11 @@ Atomics.compareExchange(i64a, 0, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-exchange.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-exchange.js
index 23b63d38fc..d50a5c20ff 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-exchange.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-exchange.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,8 +32,12 @@ Atomics.exchange(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-or.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-or.js
index 352642bfa5..29d0adb0fe 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-or.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-or.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,9 +32,13 @@ Atomics.or(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-store.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-store.js
index 7f955ac2c0..646a6ea4f5 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-store.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-store.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,8 +32,12 @@ Atomics.store(i64a, 0, 0x111111);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-sub.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-sub.js
index 68bcdea9a3..b60d398743 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-sub.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-sub.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,7 +32,11 @@ Atomics.sub(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-xor.js b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-xor.js
index b06ac9565c..542a3f4335 100644
--- a/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-xor.js
+++ b/test/built-ins/Atomics/wait/bigint/no-spurious-wakeup-on-xor.js
@@ -17,7 +17,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${TIMEOUT});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${TIMEOUT});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -32,10 +32,14 @@ Atomics.xor(i64a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i64a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i64a, 0), 0, 'Atomics.wake(i64a, 0) returns 0');
 
 
 
diff --git a/test/built-ins/Atomics/wait/bigint/non-bigint64-typedarray-throws.js b/test/built-ins/Atomics/wait/bigint/non-bigint64-typedarray-throws.js
index 6278a5c328..e6437c19df 100644
--- a/test/built-ins/Atomics/wait/bigint/non-bigint64-typedarray-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/non-bigint64-typedarray-throws.js
@@ -16,7 +16,7 @@ info: |
 
   ...
   5. If waitable is true, then
-      a. If typeName is not "Int32Array" or "BigInt64Array",
+      a. If typeName is not "BigInt64Array",
       throw a TypeError exception.
 
 features: [Atomics, BigInt, SharedArrayBuffer, TypedArray, ArrayBuffer, DataView, let, arrow-function, for-of, Atomics, BigInt, SharedArrayBuffer, TypedArray]
@@ -34,10 +34,10 @@ const poisoned = {
 };
 
 assert.throws(TypeError, function() {
-  Atomics.wait(i64a, 0, 0, 0);
-}, 'BigUint64Array');
+  Atomics.wait(i64a, 0, 0n, 0);
+}, '`Atomics.wait(i64a, 0, 0n, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i64a, poisoned, poisoned, poisoned);
-}, 'BigUint64Array');
+}, '`Atomics.wait(i64a, poisoned, poisoned, poisoned)` throws TypeError');
 
diff --git a/test/built-ins/Atomics/wait/bigint/non-shared-bufferdata-throws.js b/test/built-ins/Atomics/wait/bigint/non-shared-bufferdata-throws.js
index cbe7776b1d..fefbd333b2 100644
--- a/test/built-ins/Atomics/wait/bigint/non-shared-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/non-shared-bufferdata-throws.js
@@ -26,9 +26,9 @@ const poisoned = {
 };
 
 assert.throws(TypeError, function() {
-  Atomics.wait(i64a, 0, 0, 0);
-}, 'Atomics.wait(i64a, 0, 0, 0) on ArrayBuffer throws TypeError');
+  Atomics.wait(i64a, 0, 0n, 0);
+}, '`Atomics.wait(i64a, 0, 0n, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i64a, poisoned, poisoned, poisoned);
-}, 'Atomics.wait(i64a, poisoned, poisoned, poisoned) on ArrayBuffer throws TypeError');
+}, '`Atomics.wait(i64a, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/bigint/null-bufferdata-throws.js b/test/built-ins/Atomics/wait/bigint/null-bufferdata-throws.js
index 0420510c6b..ae4e3c2a0e 100644
--- a/test/built-ins/Atomics/wait/bigint/null-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/null-bufferdata-throws.js
@@ -42,4 +42,4 @@ try {
 
 assert.throws(TypeError, function() {
   Atomics.wait(i64a, poisoned, poisoned, poisoned);
-}, 'Atomics.wait(i64a, poisoned, poisoned, poisoned) on detached buffer throws TypeError');
+}, '`Atomics.wait(i64a, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/bigint/out-of-range-index-throws.js b/test/built-ins/Atomics/wait/bigint/out-of-range-index-throws.js
index d4d936860b..ac029a9f60 100644
--- a/test/built-ins/Atomics/wait/bigint/out-of-range-index-throws.js
+++ b/test/built-ins/Atomics/wait/bigint/out-of-range-index-throws.js
@@ -28,10 +28,10 @@ const poisoned = {
 
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, Infinity, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, Infinity, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, 2, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, 2, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i64a, 200, poisoned, poisoned);
-});
+}, '`Atomics.wait(i64a, 200, poisoned, poisoned)` throws RangeError');
diff --git a/test/built-ins/Atomics/wait/bigint/value-not-equal.js b/test/built-ins/Atomics/wait/bigint/value-not-equal.js
index c67f828080..99be75f72d 100644
--- a/test/built-ins/Atomics/wait/bigint/value-not-equal.js
+++ b/test/built-ins/Atomics/wait/bigint/value-not-equal.js
@@ -18,12 +18,12 @@ includes: [atomicsHelper.js]
 features: [Atomics, BigInt, SharedArrayBuffer, TypedArray]
 ---*/
 
-var value = 42;
+const value = 42n;
 
 $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
-
+    Atomics.add(i64a, 1, 1);
     $262.agent.report(Atomics.store(i64a, 0, ${value}));
     $262.agent.report(Atomics.wait(i64a, 0, 0));
     $262.agent.leaving();
@@ -35,8 +35,16 @@ const i64a = new BigInt64Array(
 );
 
 $262.agent.broadcast(i64a.buffer);
-$262.agent.sleep(100);
+$262.agent.waitUntil(i64a, 1, 1);
 
-assert.sameValue($262.agent.getReport(), value.toString());
-assert.sameValue($262.agent.getReport(), 'not-equal');
+assert.sameValue(
+  $262.agent.getReport(),
+  '42',
+  '$262.agent.getReport() returns "42"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'not-equal',
+  '$262.agent.getReport() returns "not-equal"'
+);
 
diff --git a/test/built-ins/Atomics/wait/bigint/waiterlist-order-of-operations-is-fifo.js b/test/built-ins/Atomics/wait/bigint/waiterlist-order-of-operations-is-fifo.js
index 95a554b72d..f9758bac6a 100644
--- a/test/built-ins/Atomics/wait/bigint/waiterlist-order-of-operations-is-fifo.js
+++ b/test/built-ins/Atomics/wait/bigint/waiterlist-order-of-operations-is-fifo.js
@@ -24,7 +24,7 @@ $262.agent.start(`
     const i64a = new BigInt64Array(sab);
 
     $262.agent.report(${agent1});
-    $262.agent.report(Atomics.wait(i64a, 1, 0));
+    $262.agent.report(Atomics.wait(i64a, 1, 0n));
     $262.agent.report(${agent1});
     $262.agent.leaving();
   });
@@ -35,7 +35,7 @@ $262.agent.start(`
     const i64a = new BigInt64Array(sab);
 
     $262.agent.report(${agent2});
-    $262.agent.report(Atomics.wait(i64a, 2, 0));
+    $262.agent.report(Atomics.wait(i64a, 2, 0n));
     $262.agent.report(${agent2});
     $262.agent.leaving();
   });
@@ -46,7 +46,7 @@ $262.agent.start(`
     const i64a = new BigInt64Array(sab);
 
     $262.agent.report(${agent3});
-    $262.agent.report(Atomics.wait(i64a, 3, 0));
+    $262.agent.report(Atomics.wait(i64a, 3, 0n));
     $262.agent.report(${agent3});
     $262.agent.leaving();
   });
@@ -64,14 +64,26 @@ $262.agent.sleep(100);
 const started = [$262.agent.getReport(), $262.agent.getReport(), $262.agent.getReport()];
 
 // Agents must wake in the order they waited
-assert.sameValue(Atomics.wake(i64a, 1, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[0]);
+assert.sameValue(Atomics.wake(i64a, 1, 1), 1, 'Atomics.wake(i64a, 1, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[0],
+  `$262.agent.getReport() returns the value of 'started[0]' (${started[0]})`
+);
 
-assert.sameValue(Atomics.wake(i64a, 2, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[1]);
+assert.sameValue(Atomics.wake(i64a, 2, 1), 1, 'Atomics.wake(i64a, 2, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[1],
+  `$262.agent.getReport() returns the value of 'started[1]' (${started[1]})`
+);
 
-assert.sameValue(Atomics.wake(i64a, 3, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[2]);
+assert.sameValue(Atomics.wake(i64a, 3, 1), 1, 'Atomics.wake(i64a, 3, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[2],
+  `$262.agent.getReport() returns the value of 'started[2]' (${started[2]})`
+);
diff --git a/test/built-ins/Atomics/wait/bigint/was-woken-before-timeout.js b/test/built-ins/Atomics/wait/bigint/was-woken-before-timeout.js
index d9084dcdf5..48ad7d3abe 100644
--- a/test/built-ins/Atomics/wait/bigint/was-woken-before-timeout.js
+++ b/test/built-ins/Atomics/wait/bigint/was-woken-before-timeout.js
@@ -29,7 +29,7 @@ $262.agent.start(`
   $262.agent.receiveBroadcast(function(sab) {
     const i64a = new BigInt64Array(sab);
     const before = $262.agent.monotonicNow();
-    const unpark = Atomics.wait(i64a, 0, 0, ${timeout});
+    const unpark = Atomics.wait(i64a, 0, 0n, ${timeout});
     $262.agent.report($262.agent.monotonicNow() - before);
     $262.agent.report(unpark);
     $262.agent.leaving();
@@ -43,14 +43,14 @@ const i64a = new BigInt64Array(
 $262.agent.broadcast(i64a.buffer);
 $262.agent.sleep(sleeping);
 
-assert.sameValue(Atomics.wake(i64a, 0), 1);
+assert.sameValue(Atomics.wake(i64a, 0), 1, 'Atomics.wake(i64a, 0) returns 1');
 
 const lapse = $262.agent.getReport();
 
 assert(
   sleeping + lapse < timeout,
-  `${sleeping + lapse} should be less than ${timeout}`
+  'The result of `(sleeping + lapse < timeout)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'ok');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
 
 
diff --git a/test/built-ins/Atomics/wait/cannot-suspend-throws.js b/test/built-ins/Atomics/wait/cannot-suspend-throws.js
index 39792eb682..48941b8cab 100644
--- a/test/built-ins/Atomics/wait/cannot-suspend-throws.js
+++ b/test/built-ins/Atomics/wait/cannot-suspend-throws.js
@@ -24,4 +24,4 @@ const i32a = new Int32Array(
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, 0, 0);
-});
+}, '`Atomics.wait(i32a, 0, 0, 0)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/false-for-timeout-agent.js b/test/built-ins/Atomics/wait/false-for-timeout-agent.js
index 1bdda0a50e..85bd22bc85 100644
--- a/test/built-ins/Atomics/wait/false-for-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/false-for-timeout-agent.js
@@ -47,15 +47,27 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(100);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
 
 var lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
 
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, `timeout should be a max of ${$262.agent.MAX_TIME_EPSILON}`);
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true)');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/false-for-timeout.js b/test/built-ins/Atomics/wait/false-for-timeout.js
index b79fe25fe3..c008d21f61 100644
--- a/test/built-ins/Atomics/wait/false-for-timeout.js
+++ b/test/built-ins/Atomics/wait/false-for-timeout.js
@@ -32,7 +32,19 @@ const toPrimitive = {
   }
 };
 
-assert.sameValue(Atomics.wait(i32a, 0, 0, false), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, valueOf), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, toPrimitive), 'timed-out');
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, false),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, false) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, valueOf),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, valueOf) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, toPrimitive),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, toPrimitive) returns "timed-out"'
+);
 
diff --git a/test/built-ins/Atomics/wait/good-views.js b/test/built-ins/Atomics/wait/good-views.js
index 536293c23e..f699c69346 100644
--- a/test/built-ins/Atomics/wait/good-views.js
+++ b/test/built-ins/Atomics/wait/good-views.js
@@ -44,6 +44,18 @@ $262.agent.start(`
   $262.agent.leaving();
 `);
 
-assert.sameValue($262.agent.getReport(), 'A timed-out');
-assert.sameValue($262.agent.getReport(), 'B not-equal');
-assert.sameValue($262.agent.getReport(), 'C not-equal');
+assert.sameValue(
+  $262.agent.getReport(),
+  'A timed-out',
+  '$262.agent.getReport() returns "A timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'B not-equal',
+  '$262.agent.getReport() returns "B not-equal"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'C not-equal',
+  '$262.agent.getReport() returns "C not-equal"'
+);
diff --git a/test/built-ins/Atomics/wait/nan-for-timeout.js b/test/built-ins/Atomics/wait/nan-for-timeout.js
index 7ae886c772..3a1b109e0d 100644
--- a/test/built-ins/Atomics/wait/nan-for-timeout.js
+++ b/test/built-ins/Atomics/wait/nan-for-timeout.js
@@ -32,5 +32,5 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(500); // Ample time
 
-assert.sameValue(Atomics.wake(i32a, 0), 1);
-assert.sameValue($262.agent.getReport(), "ok");
+assert.sameValue(Atomics.wake(i32a, 0), 1, 'Atomics.wake(i32a, 0) returns 1');
+assert.sameValue($262.agent.getReport(), "ok", '$262.agent.getReport() returns "ok"');
diff --git a/test/built-ins/Atomics/wait/negative-index-throws.js b/test/built-ins/Atomics/wait/negative-index-throws.js
index 5cb009486f..0c2ecffcf5 100644
--- a/test/built-ins/Atomics/wait/negative-index-throws.js
+++ b/test/built-ins/Atomics/wait/negative-index-throws.js
@@ -30,13 +30,13 @@ const poisoned = {
 
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, -Infinity, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, -Infinity, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, -7.999, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, -7.999, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, -1, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, -1, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, -300, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, -300, poisoned, poisoned)` throws RangeError');
diff --git a/test/built-ins/Atomics/wait/negative-timeout-agent.js b/test/built-ins/Atomics/wait/negative-timeout-agent.js
index 4b93eeb05f..15ee04348d 100644
--- a/test/built-ins/Atomics/wait/negative-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/negative-timeout-agent.js
@@ -24,5 +24,9 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(100);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/negative-timeout.js b/test/built-ins/Atomics/wait/negative-timeout.js
index 97a2ed91dd..59c74af2c0 100644
--- a/test/built-ins/Atomics/wait/negative-timeout.js
+++ b/test/built-ins/Atomics/wait/negative-timeout.js
@@ -13,4 +13,8 @@ const i32a = new Int32Array(
   new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
 );
 
-assert.sameValue(Atomics.wait(i32a, 0, 0, -1), "timed-out");
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, -1),
+  "timed-out",
+  'Atomics.wait(i32a, 0, 0, -1) returns "timed-out"'
+);
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-add.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-add.js
index 4ed4cc2b37..6e43276b66 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-add.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-add.js
@@ -33,9 +33,13 @@ Atomics.add(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-and.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-and.js
index 66f6bc7c03..2d6216185b 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-and.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-and.js
@@ -33,9 +33,13 @@ Atomics.and(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-compareExchange.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-compareExchange.js
index fdb8bd04fe..d48ad4bf56 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-compareExchange.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-compareExchange.js
@@ -33,7 +33,11 @@ Atomics.compareExchange(i32a, 0, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-exchange.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-exchange.js
index 6976bcdfcc..11a9cc295f 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-exchange.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-exchange.js
@@ -33,8 +33,12 @@ Atomics.exchange(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-or.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-or.js
index 847706e762..7e39a50df1 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-or.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-or.js
@@ -33,9 +33,13 @@ Atomics.or(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
 
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-store.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-store.js
index e2e918fab4..bff44f4f1d 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-store.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-store.js
@@ -33,8 +33,12 @@ Atomics.store(i32a, 0, 0x111111);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-sub.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-sub.js
index 196d3d2604..317157442b 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-sub.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-sub.js
@@ -33,7 +33,11 @@ Atomics.sub(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-xor.js b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-xor.js
index 83c7c97af9..e4e0014373 100644
--- a/test/built-ins/Atomics/wait/no-spurious-wakeup-on-xor.js
+++ b/test/built-ins/Atomics/wait/no-spurious-wakeup-on-xor.js
@@ -33,10 +33,14 @@ Atomics.xor(i32a, 0, 1);
 const lapse = $262.agent.getReport();
 assert(
   lapse >= TIMEOUT,
-  `${lapse} should be at least ${TIMEOUT}`
+  'The result of `(lapse >= TIMEOUT)` is true (The result of `(lapse >= TIMEOUT)` is true)'
 );
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
 
 
diff --git a/test/built-ins/Atomics/wait/non-int32-typedarray-throws.js b/test/built-ins/Atomics/wait/non-int32-typedarray-throws.js
index b0de7bcef9..fd9df6169f 100644
--- a/test/built-ins/Atomics/wait/non-int32-typedarray-throws.js
+++ b/test/built-ins/Atomics/wait/non-int32-typedarray-throws.js
@@ -26,53 +26,53 @@ assert.throws(TypeError, function() {
     new SharedArrayBuffer(Float64Array.BYTES_PER_ELEMENT * 8)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Float64Array');
+}, '`const view = new Float64Array( new SharedArrayBuffer(Float64Array.BYTES_PER_ELEMENT * 8) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Float32Array(
     new SharedArrayBuffer(Float32Array.BYTES_PER_ELEMENT * 4)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Float32Array');
+}, '`const view = new Float32Array( new SharedArrayBuffer(Float32Array.BYTES_PER_ELEMENT * 4) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Int16Array(
     new SharedArrayBuffer(Int16Array.BYTES_PER_ELEMENT * 2)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Int16Array');
+}, '`const view = new Int16Array( new SharedArrayBuffer(Int16Array.BYTES_PER_ELEMENT * 2) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Int8Array(
     new SharedArrayBuffer(Int8Array.BYTES_PER_ELEMENT)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Int8Array');
+}, '`const view = new Int8Array( new SharedArrayBuffer(Int8Array.BYTES_PER_ELEMENT) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint32Array(
     new SharedArrayBuffer(Uint32Array.BYTES_PER_ELEMENT * 4)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Uint32Array');
+}, '`const view = new Uint32Array( new SharedArrayBuffer(Uint32Array.BYTES_PER_ELEMENT * 4) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint16Array(
     new SharedArrayBuffer(Uint16Array.BYTES_PER_ELEMENT * 2)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Uint16Array');
+}, '`const view = new Uint16Array( new SharedArrayBuffer(Uint16Array.BYTES_PER_ELEMENT * 2) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint8Array(
     new SharedArrayBuffer(Uint8Array.BYTES_PER_ELEMENT)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Uint8Array');
+}, '`const view = new Uint8Array( new SharedArrayBuffer(Uint8Array.BYTES_PER_ELEMENT) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint8ClampedArray(
     new SharedArrayBuffer(Uint8ClampedArray.BYTES_PER_ELEMENT)
   );
   Atomics.wait(view, poisoned, poisoned, poisoned);
-}, 'Uint8ClampedArray');
+}, '`const view = new Uint8ClampedArray( new SharedArrayBuffer(Uint8ClampedArray.BYTES_PER_ELEMENT) ); Atomics.wait(view, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/non-shared-bufferdata-throws.js b/test/built-ins/Atomics/wait/non-shared-bufferdata-throws.js
index 164af59e2b..4da17d0bd4 100644
--- a/test/built-ins/Atomics/wait/non-shared-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wait/non-shared-bufferdata-throws.js
@@ -27,8 +27,8 @@ const poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, 0, 0);
-});
+}, '`Atomics.wait(i32a, 0, 0, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, poisoned, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/not-a-typedarray-throws.js b/test/built-ins/Atomics/wait/not-a-typedarray-throws.js
index 108f235397..62b7388f11 100644
--- a/test/built-ins/Atomics/wait/not-a-typedarray-throws.js
+++ b/test/built-ins/Atomics/wait/not-a-typedarray-throws.js
@@ -22,8 +22,8 @@ var poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wait({}, 0, 0, 0);
-});
+}, '`Atomics.wait({}, 0, 0, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait({}, poisoned, poisoned, poisoned);
-});
+}, '`Atomics.wait({}, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/not-an-object-throws.js b/test/built-ins/Atomics/wait/not-an-object-throws.js
index bcd44c9a3a..ce1c0a4937 100644
--- a/test/built-ins/Atomics/wait/not-an-object-throws.js
+++ b/test/built-ins/Atomics/wait/not-an-object-throws.js
@@ -21,28 +21,28 @@ var poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wait(null, poisoned, poisoned, poisoned);
-}, 'null');
+}, '`Atomics.wait(null, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(undefined, poisoned, poisoned, poisoned);
-}, 'undefined');
+}, '`Atomics.wait(undefined, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(true, poisoned, poisoned, poisoned);
-}, 'true');
+}, '`Atomics.wait(true, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(false, poisoned, poisoned, poisoned);
-}, 'false');
+}, '`Atomics.wait(false, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait('***string***', poisoned, poisoned, poisoned);
-}, 'String');
+}, '`Atomics.wait(\'***string***\', poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(Number.NEGATIVE_INFINITY, poisoned, poisoned, poisoned);
-}, 'Number.NEGATIVE_INFINITY');
+}, '`Atomics.wait(Number.NEGATIVE_INFINITY, poisoned, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(Symbol('***symbol***'), poisoned, poisoned, poisoned);
-}, 'Symbol');
+}, '`Atomics.wait(Symbol(\'***symbol***\'), poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/null-bufferdata-throws.js b/test/built-ins/Atomics/wait/null-bufferdata-throws.js
index 27bf1f272a..b2a562de7b 100644
--- a/test/built-ins/Atomics/wait/null-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wait/null-bufferdata-throws.js
@@ -34,4 +34,4 @@ try {
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, poisoned, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, poisoned, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/null-for-timeout-agent.js b/test/built-ins/Atomics/wait/null-for-timeout-agent.js
index 6ba9a4f5b7..e9add11675 100644
--- a/test/built-ins/Atomics/wait/null-for-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/null-for-timeout-agent.js
@@ -47,15 +47,27 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
 
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $262.agent.MAX_TIME_EPSILON');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/null-for-timeout.js b/test/built-ins/Atomics/wait/null-for-timeout.js
index 63c3780c6c..63068dfb20 100644
--- a/test/built-ins/Atomics/wait/null-for-timeout.js
+++ b/test/built-ins/Atomics/wait/null-for-timeout.js
@@ -32,7 +32,19 @@ const toPrimitive = {
   }
 };
 
-assert.sameValue(Atomics.wait(i32a, 0, 0, null), "timed-out");
-assert.sameValue(Atomics.wait(i32a, 0, 0, valueOf), "timed-out");
-assert.sameValue(Atomics.wait(i32a, 0, 0, toPrimitive), "timed-out");
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, null),
+  "timed-out",
+  'Atomics.wait(i32a, 0, 0, null) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, valueOf),
+  "timed-out",
+  'Atomics.wait(i32a, 0, 0, valueOf) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, toPrimitive),
+  "timed-out",
+  'Atomics.wait(i32a, 0, 0, toPrimitive) returns "timed-out"'
+);
 
diff --git a/test/built-ins/Atomics/wait/object-for-timeout-agent.js b/test/built-ins/Atomics/wait/object-for-timeout-agent.js
index 6446096693..12892f9e90 100644
--- a/test/built-ins/Atomics/wait/object-for-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/object-for-timeout-agent.js
@@ -52,15 +52,27 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
 
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/object-for-timeout.js b/test/built-ins/Atomics/wait/object-for-timeout.js
index 6af1359955..4699294d6c 100644
--- a/test/built-ins/Atomics/wait/object-for-timeout.js
+++ b/test/built-ins/Atomics/wait/object-for-timeout.js
@@ -42,6 +42,18 @@ const toPrimitive = {
   }
 };
 
-assert.sameValue(Atomics.wait(i32a, 0, 0, valueOf), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, toString), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, toPrimitive), 'timed-out');
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, valueOf),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, valueOf) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, toString),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, toString) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, toPrimitive),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, toPrimitive) returns "timed-out"'
+);
diff --git a/test/built-ins/Atomics/wait/out-of-range-index-throws.js b/test/built-ins/Atomics/wait/out-of-range-index-throws.js
index a50c31113d..023bb7237c 100644
--- a/test/built-ins/Atomics/wait/out-of-range-index-throws.js
+++ b/test/built-ins/Atomics/wait/out-of-range-index-throws.js
@@ -28,13 +28,13 @@ const poisoned = {
 
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, Infinity, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, Infinity, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, -1, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, -1, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, 4, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, 4, poisoned, poisoned)` throws RangeError');
 assert.throws(RangeError, function() {
   Atomics.wait(i32a, 200, poisoned, poisoned);
-});
+}, '`Atomics.wait(i32a, 200, poisoned, poisoned)` throws RangeError');
diff --git a/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws-agent.js b/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws-agent.js
index 6642ccfe3a..be288ee5f7 100644
--- a/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws-agent.js
+++ b/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws-agent.js
@@ -54,14 +54,22 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'poisonedValueOf');
-assert.sameValue($262.agent.getReport(), 'poisonedToPrimitive');
+assert.sameValue(
+  $262.agent.getReport(),
+  'poisonedValueOf',
+  '$262.agent.getReport() returns "poisonedValueOf"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'poisonedToPrimitive',
+  '$262.agent.getReport() returns "poisonedToPrimitive"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
 
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws.js b/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws.js
index b29c961039..e2880c29f4 100644
--- a/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws.js
+++ b/test/built-ins/Atomics/wait/poisoned-object-for-timeout-throws.js
@@ -36,8 +36,8 @@ const poisonedToPrimitive = {
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, 0, poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, 0, 0, poisonedValueOf)` throws Test262Error');
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, 0, poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, 0, 0, poisonedToPrimitive)` throws Test262Error');
diff --git a/test/built-ins/Atomics/wait/symbol-for-index-throws-agent.js b/test/built-ins/Atomics/wait/symbol-for-index-throws-agent.js
index 7065e97a85..86e533b3dc 100644
--- a/test/built-ins/Atomics/wait/symbol-for-index-throws-agent.js
+++ b/test/built-ins/Atomics/wait/symbol-for-index-throws-agent.js
@@ -67,13 +67,21 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'Symbol("1")');
-assert.sameValue($262.agent.getReport(), 'Symbol("2")');
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("1")',
+  '$262.agent.getReport() returns "Symbol("1")"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("2")',
+  '$262.agent.getReport() returns "Symbol("2")"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/symbol-for-index-throws.js b/test/built-ins/Atomics/wait/symbol-for-index-throws.js
index 0956311742..77a562f015 100644
--- a/test/built-ins/Atomics/wait/symbol-for-index-throws.js
+++ b/test/built-ins/Atomics/wait/symbol-for-index-throws.js
@@ -46,16 +46,16 @@ const poisonedToPrimitive = {
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, poisonedValueOf, poisonedValueOf, poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, poisonedValueOf, poisonedValueOf, poisonedValueOf)` throws Test262Error');
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, poisonedToPrimitive, poisonedToPrimitive, poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, poisonedToPrimitive, poisonedToPrimitive, poisonedToPrimitive)` throws Test262Error');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, Symbol('foo'), poisonedValueOf, poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, Symbol(\'foo\'), poisonedValueOf, poisonedValueOf)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, Symbol('foo'), poisonedToPrimitive, poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, Symbol(\'foo\'), poisonedToPrimitive, poisonedToPrimitive)` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/symbol-for-timeout-throws-agent.js b/test/built-ins/Atomics/wait/symbol-for-timeout-throws-agent.js
index a0b3316558..640cda2060 100644
--- a/test/built-ins/Atomics/wait/symbol-for-timeout-throws-agent.js
+++ b/test/built-ins/Atomics/wait/symbol-for-timeout-throws-agent.js
@@ -41,12 +41,20 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'Symbol("1")');
-assert.sameValue($262.agent.getReport(), 'Symbol("2")');
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("1")',
+  '$262.agent.getReport() returns "Symbol("1")"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("2")',
+  '$262.agent.getReport() returns "Symbol("2")"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/symbol-for-timeout-throws.js b/test/built-ins/Atomics/wait/symbol-for-timeout-throws.js
index 6030e0fd13..7d2afedd3f 100644
--- a/test/built-ins/Atomics/wait/symbol-for-timeout-throws.js
+++ b/test/built-ins/Atomics/wait/symbol-for-timeout-throws.js
@@ -32,16 +32,16 @@ var poisonedToPrimitive = {
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, 0, poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, 0, 0, poisonedValueOf)` throws Test262Error');
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, 0, poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, 0, 0, poisonedToPrimitive)` throws Test262Error');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, 0, Symbol("foo"));
-});
+}, '`Atomics.wait(i32a, 0, 0, Symbol("foo"))` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, 0, Symbol("foo"));
-});
+}, '`Atomics.wait(i32a, 0, 0, Symbol("foo"))` throws TypeError');
diff --git a/test/built-ins/Atomics/wait/symbol-for-value-throws-agent.js b/test/built-ins/Atomics/wait/symbol-for-value-throws-agent.js
index 6a2faa17db..1206fe1c14 100644
--- a/test/built-ins/Atomics/wait/symbol-for-value-throws-agent.js
+++ b/test/built-ins/Atomics/wait/symbol-for-value-throws-agent.js
@@ -58,12 +58,20 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'Symbol("1")');
-assert.sameValue($262.agent.getReport(), 'Symbol("2")');
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("1")',
+  '$262.agent.getReport() returns "Symbol("1")"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'Symbol("2")',
+  '$262.agent.getReport() returns "Symbol("2")"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/symbol-for-value-throws.js b/test/built-ins/Atomics/wait/symbol-for-value-throws.js
index d34cf24858..c414005e67 100644
--- a/test/built-ins/Atomics/wait/symbol-for-value-throws.js
+++ b/test/built-ins/Atomics/wait/symbol-for-value-throws.js
@@ -37,17 +37,17 @@ const poisonedToPrimitive = {
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, poisonedValueOf, poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, 0, poisonedValueOf, poisonedValueOf)` throws Test262Error');
 
 assert.throws(Test262Error, function() {
   Atomics.wait(i32a, 0, poisonedToPrimitive, poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, 0, poisonedToPrimitive, poisonedToPrimitive)` throws Test262Error');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, Symbol("foo"), poisonedValueOf);
-});
+}, '`Atomics.wait(i32a, 0, Symbol("foo"), poisonedValueOf)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i32a, 0, Symbol("foo"), poisonedToPrimitive);
-});
+}, '`Atomics.wait(i32a, 0, Symbol("foo"), poisonedToPrimitive)` throws TypeError');
 
diff --git a/test/built-ins/Atomics/wait/true-for-timeout-agent.js b/test/built-ins/Atomics/wait/true-for-timeout-agent.js
index be3adbb639..1b8e090a13 100644
--- a/test/built-ins/Atomics/wait/true-for-timeout-agent.js
+++ b/test/built-ins/Atomics/wait/true-for-timeout-agent.js
@@ -47,15 +47,27 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
-assert.sameValue($262.agent.getReport(), 'timed-out');
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'timed-out',
+  '$262.agent.getReport() returns "timed-out"'
+);
 
 const lapse = $262.agent.getReport();
 
-assert(lapse >= 0, 'timeout should be a min of 0ms');
+assert(lapse >= 0, 'The result of `(lapse >= 0)` is true (The result of `(lapse >= 0)` is true (timeout should be a min of 0ms))');
 
-assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'timeout should be a max of $$262.agent.MAX_TIME_EPSILON');
+assert(lapse <= $262.agent.MAX_TIME_EPSILON, 'The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (The result of `(lapse <= $262.agent.MAX_TIME_EPSILON)` is true (timeout should be a max of $$262.agent.MAX_TIME_EPSILON))');
 
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
 
diff --git a/test/built-ins/Atomics/wait/true-for-timeout.js b/test/built-ins/Atomics/wait/true-for-timeout.js
index 64b4b8710b..1db2adc508 100644
--- a/test/built-ins/Atomics/wait/true-for-timeout.js
+++ b/test/built-ins/Atomics/wait/true-for-timeout.js
@@ -32,7 +32,19 @@ const toPrimitive = {
   }
 };
 
-assert.sameValue(Atomics.wait(i32a, 0, 0, true), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, valueOf), 'timed-out');
-assert.sameValue(Atomics.wait(i32a, 0, 0, toPrimitive), 'timed-out');
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, true),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, true) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, valueOf),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, valueOf) returns "timed-out"'
+);
+assert.sameValue(
+  Atomics.wait(i32a, 0, 0, toPrimitive),
+  'timed-out',
+  'Atomics.wait(i32a, 0, 0, toPrimitive) returns "timed-out"'
+);
 
diff --git a/test/built-ins/Atomics/wait/undefined-for-timeout.js b/test/built-ins/Atomics/wait/undefined-for-timeout.js
index fd38c69ab3..304d40d4ef 100644
--- a/test/built-ins/Atomics/wait/undefined-for-timeout.js
+++ b/test/built-ins/Atomics/wait/undefined-for-timeout.js
@@ -49,7 +49,11 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
 
-assert.sameValue(Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT), WAKECOUNT);
+assert.sameValue(
+  Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT),
+  WAKECOUNT,
+  'Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT) returns the value of `WAKECOUNT` (2)'
+);
 
 const reports = [];
 for (var i = 0; i < NUMAGENT; i++) {
@@ -57,5 +61,5 @@ for (var i = 0; i < NUMAGENT; i++) {
 }
 reports.sort();
 
-assert.sameValue(reports[0], 'A ok');
-assert.sameValue(reports[1], 'B ok');
+assert.sameValue(reports[0], 'A ok', 'The value of reports[0] is "A ok"');
+assert.sameValue(reports[1], 'B ok', 'The value of reports[1] is "B ok"');
diff --git a/test/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js b/test/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js
index 6a01b06d9f..eff3c7167b 100644
--- a/test/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js
+++ b/test/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js
@@ -37,6 +37,6 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(150);
 
-assert.sameValue(Atomics.wake(i32a, 0), 1); // wake at index 0
-assert.sameValue(Atomics.wake(i32a, 0), 0); // wake again at index 0, and 0 agents should be woken
-assert.sameValue($262.agent.getReport(), 'ok');
+assert.sameValue(Atomics.wake(i32a, 0), 1, 'Atomics.wake(i32a, 0) returns 1'); // wake at index 0
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0'); // wake again at index 0, and 0 agents should be woken
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
diff --git a/test/built-ins/Atomics/wait/value-not-equal.js b/test/built-ins/Atomics/wait/value-not-equal.js
index 8111ba45e5..3837eef8b7 100644
--- a/test/built-ins/Atomics/wait/value-not-equal.js
+++ b/test/built-ins/Atomics/wait/value-not-equal.js
@@ -36,6 +36,14 @@ const i32a = new Int32Array(
 
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(100);
-assert.sameValue($262.agent.getReport(), value.toString());
-assert.sameValue($262.agent.getReport(), 'not-equal');
+assert.sameValue(
+  $262.agent.getReport(),
+  value.toString(),
+  '$262.agent.getReport() returns value.toString()'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'not-equal',
+  '$262.agent.getReport() returns "not-equal"'
+);
 
diff --git a/test/built-ins/Atomics/wait/wait-index-value-not-equal.js b/test/built-ins/Atomics/wait/wait-index-value-not-equal.js
index 19c6c90a70..a9a6003f2b 100644
--- a/test/built-ins/Atomics/wait/wait-index-value-not-equal.js
+++ b/test/built-ins/Atomics/wait/wait-index-value-not-equal.js
@@ -33,6 +33,14 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(100);
 
-assert.sameValue($262.agent.getReport(), 'not-equal');
-assert.sameValue($262.agent.getReport(), 'not-equal');
-assert.sameValue(Atomics.wake(i32a, 0), 0);
+assert.sameValue(
+  $262.agent.getReport(),
+  'not-equal',
+  '$262.agent.getReport() returns "not-equal"'
+);
+assert.sameValue(
+  $262.agent.getReport(),
+  'not-equal',
+  '$262.agent.getReport() returns "not-equal"'
+);
+assert.sameValue(Atomics.wake(i32a, 0), 0, 'Atomics.wake(i32a, 0) returns 0');
diff --git a/test/built-ins/Atomics/wait/waiterlist-order-of-operations-is-fifo.js b/test/built-ins/Atomics/wait/waiterlist-order-of-operations-is-fifo.js
index 418dd921be..11a910e478 100644
--- a/test/built-ins/Atomics/wait/waiterlist-order-of-operations-is-fifo.js
+++ b/test/built-ins/Atomics/wait/waiterlist-order-of-operations-is-fifo.js
@@ -65,14 +65,26 @@ $262.agent.sleep(100);
 const started = [$262.agent.getReport(), $262.agent.getReport(), $262.agent.getReport()];
 
 // Agents must wake in the order they waited
-assert.sameValue(Atomics.wake(i32a, 1, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[0]);
+assert.sameValue(Atomics.wake(i32a, 1, 1), 1, 'Atomics.wake(i32a, 1, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[0],
+  '$262.agent.getReport() returns the value of `started[0]` (undefined)'
+);
 
-assert.sameValue(Atomics.wake(i32a, 2, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[1]);
+assert.sameValue(Atomics.wake(i32a, 2, 1), 1, 'Atomics.wake(i32a, 2, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[1],
+  '$262.agent.getReport() returns the value of `started[1]` (undefined)'
+);
 
-assert.sameValue(Atomics.wake(i32a, 3, 1), 1);
-assert.sameValue($262.agent.getReport(), 'ok');
-assert.sameValue($262.agent.getReport(), started[2]);
+assert.sameValue(Atomics.wake(i32a, 3, 1), 1, 'Atomics.wake(i32a, 3, 1) returns 1');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+assert.sameValue(
+  $262.agent.getReport(),
+  started[2],
+  '$262.agent.getReport() returns the value of `started[2]` (undefined)'
+);
diff --git a/test/built-ins/Atomics/wait/was-woken-before-timeout.js b/test/built-ins/Atomics/wait/was-woken-before-timeout.js
index ba5c9ee4dc..24673df84c 100644
--- a/test/built-ins/Atomics/wait/was-woken-before-timeout.js
+++ b/test/built-ins/Atomics/wait/was-woken-before-timeout.js
@@ -43,14 +43,14 @@ const i32a = new Int32Array(
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(sleeping);
 
-assert.sameValue(Atomics.wake(i32a, 0), 1);
+assert.sameValue(Atomics.wake(i32a, 0), 1, 'Atomics.wake(i32a, 0) returns 1');
 
 const lapse = $262.agent.getReport();
 
 assert(
   sleeping + lapse < timeout,
-  `${sleeping + lapse} should be less than ${timeout}`
+  'The result of `(sleeping + lapse < timeout)` is true'
 );
-assert.sameValue($262.agent.getReport(), 'ok');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
 
 
diff --git a/test/built-ins/Atomics/wake/bad-range.js b/test/built-ins/Atomics/wake/bad-range.js
index 5db7b2f2a5..880ea7fbd2 100644
--- a/test/built-ins/Atomics/wake/bad-range.js
+++ b/test/built-ins/Atomics/wake/bad-range.js
@@ -22,5 +22,5 @@ const i32a = new Int32Array(
 testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
   assert.throws(RangeError, function() {
     Atomics.wake(i32a, IdxGen(i32a), 0);
-  }, 'Atomics.wake(i32a, IdxGen(i32a), 0) throws RangeError');
+  }, '`Atomics.wake(i32a, IdxGen(i32a), 0)` throws RangeError');
 });
diff --git a/test/built-ins/Atomics/wake/bigint/non-bigint64-typedarray-throws.js b/test/built-ins/Atomics/wake/bigint/non-bigint64-typedarray-throws.js
index d60d5b6c0d..287911c474 100644
--- a/test/built-ins/Atomics/wake/bigint/non-bigint64-typedarray-throws.js
+++ b/test/built-ins/Atomics/wake/bigint/non-bigint64-typedarray-throws.js
@@ -27,8 +27,8 @@ const poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wait(i64a, 0, 0);
-}, 'BigUint64Array');
+}, '`Atomics.wait(i64a, 0, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wait(i64a, poisoned, poisoned);
-}, 'BigUint64Array');
+}, '`Atomics.wait(i64a, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/bigint/non-shared-bufferdata-throws.js b/test/built-ins/Atomics/wake/bigint/non-shared-bufferdata-throws.js
index a50363cd57..99bf204576 100644
--- a/test/built-ins/Atomics/wake/bigint/non-shared-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wake/bigint/non-shared-bufferdata-throws.js
@@ -26,8 +26,8 @@ const poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wake(i64a, 0, 0);
-}, 'Atomics.wake(i64a, 0, 0) on ArrayBuffer throws TypeError');
+}, '`Atomics.wake(i64a, 0, 0)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(i64a, poisoned, poisoned);
-}, 'Atomics.wake(i64a, poisoned, poisoned) on ArrayBuffer throws TypeError');
+}, '`Atomics.wake(i64a, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/bigint/null-bufferdata-throws.js b/test/built-ins/Atomics/wake/bigint/null-bufferdata-throws.js
index 3c773de4be..4d6fac5b8f 100644
--- a/test/built-ins/Atomics/wake/bigint/null-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wake/bigint/null-bufferdata-throws.js
@@ -33,4 +33,4 @@ try {
 
 assert.throws(TypeError, function() {
   Atomics.wake(i64a, poisoned, poisoned);
-}, 'Atomics.wake(i64a, poisoned, poisoned) on detached buffer throws TypeError');
+}, '`Atomics.wake(i64a, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/bigint/wake-all-on-loc.js b/test/built-ins/Atomics/wake/bigint/wake-all-on-loc.js
index 8e6568779c..d1cb63946e 100644
--- a/test/built-ins/Atomics/wake/bigint/wake-all-on-loc.js
+++ b/test/built-ins/Atomics/wake/bigint/wake-all-on-loc.js
@@ -53,7 +53,7 @@ $262.agent.sleep(50);
 assert.sameValue(
   Atomics.wake(i64a, WAIT_INDEX),
   NUMAGENT,
-  'Atomics.wake(i64a, WAIT_INDEX) equals the value of `NUMAGENT` (3)'
+  'Atomics.wake(i64a, WAIT_INDEX) returns the value of `NUMAGENT` (3)'
 );
 
 var reports = [];
diff --git a/test/built-ins/Atomics/wake/count-boundary-cases.js b/test/built-ins/Atomics/wake/count-boundary-cases.js
index c0686fb0b6..654eb4f17f 100644
--- a/test/built-ins/Atomics/wake/count-boundary-cases.js
+++ b/test/built-ins/Atomics/wake/count-boundary-cases.js
@@ -47,7 +47,7 @@ assert.sameValue(
 assert.sameValue(
   Atomics.wake(i32a, 0, '33'),
   0,
-  'Atomics.wake(i32a, 0, "33") returns 0'
+  'Atomics.wake(i32a, 0, \'33\') returns 0'
 );
 assert.sameValue(
   Atomics.wake(i32a, 0, { valueOf: 8 }),
diff --git a/test/built-ins/Atomics/wake/count-defaults-to-infinity-missing.js b/test/built-ins/Atomics/wake/count-defaults-to-infinity-missing.js
index 45ca182734..29601ae79e 100644
--- a/test/built-ins/Atomics/wake/count-defaults-to-infinity-missing.js
+++ b/test/built-ins/Atomics/wake/count-defaults-to-infinity-missing.js
@@ -69,7 +69,7 @@ $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX /*, count missing */),
   NUMAGENT,
-  'Atomics.wake(i32a, WAIT_INDEX /*, count missing */) equals the value of `NUMAGENT` (4)'
+  'Atomics.wake(i32a, WAIT_INDEX /*, count missing */) returns the value of `NUMAGENT` (4)'
 );
 
 const reports = [];
diff --git a/test/built-ins/Atomics/wake/count-defaults-to-infinity-undefined.js b/test/built-ins/Atomics/wake/count-defaults-to-infinity-undefined.js
index 74c91ca992..be5646351a 100644
--- a/test/built-ins/Atomics/wake/count-defaults-to-infinity-undefined.js
+++ b/test/built-ins/Atomics/wake/count-defaults-to-infinity-undefined.js
@@ -67,7 +67,7 @@ $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX, undefined),
   NUMAGENT,
-  'Atomics.wake(i32a, WAIT_INDEX, undefined) equals the value of `NUMAGENT` (4)'
+  'Atomics.wake(i32a, WAIT_INDEX, undefined) returns the value of `NUMAGENT` (4)'
 );
 
 const reports = [];
diff --git a/test/built-ins/Atomics/wake/non-int32-typedarray-throws.js b/test/built-ins/Atomics/wake/non-int32-typedarray-throws.js
index aea70d3e45..b949e20aeb 100644
--- a/test/built-ins/Atomics/wake/non-int32-typedarray-throws.js
+++ b/test/built-ins/Atomics/wake/non-int32-typedarray-throws.js
@@ -26,53 +26,53 @@ assert.throws(TypeError, function() {
     new SharedArrayBuffer(Float64Array.BYTES_PER_ELEMENT * 8)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Float64Array( new SharedArrayBuffer(Float64Array.BYTES_PER_ELEMENT * 8) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Float32Array(
     new SharedArrayBuffer(Float32Array.BYTES_PER_ELEMENT * 4)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Float32Array( new SharedArrayBuffer(Float32Array.BYTES_PER_ELEMENT * 4) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Int16Array(
     new SharedArrayBuffer(Int16Array.BYTES_PER_ELEMENT * 2)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Int16Array( new SharedArrayBuffer(Int16Array.BYTES_PER_ELEMENT * 2) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Int8Array(
     new SharedArrayBuffer(Int8Array.BYTES_PER_ELEMENT)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Int8Array( new SharedArrayBuffer(Int8Array.BYTES_PER_ELEMENT) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint32Array(
     new SharedArrayBuffer(Uint32Array.BYTES_PER_ELEMENT * 4)
   );
   Atomics.wake(new Uint32Array(),  poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Uint32Array( new SharedArrayBuffer(Uint32Array.BYTES_PER_ELEMENT * 4) ); Atomics.wake(new Uint32Array(), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint16Array(
     new SharedArrayBuffer(Uint16Array.BYTES_PER_ELEMENT * 2)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Uint16Array( new SharedArrayBuffer(Uint16Array.BYTES_PER_ELEMENT * 2) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint8Array(
     new SharedArrayBuffer(Uint8Array.BYTES_PER_ELEMENT)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wait(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Uint8Array( new SharedArrayBuffer(Uint8Array.BYTES_PER_ELEMENT) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   const view = new Uint8ClampedArray(
     new SharedArrayBuffer(Uint8ClampedArray.BYTES_PER_ELEMENT)
   );
   Atomics.wake(view, poisoned, poisoned);
-}, '`Atomics.wake(view), poisoned, poisoned)` throws TypeError');
+}, '`const view = new Uint8ClampedArray( new SharedArrayBuffer(Uint8ClampedArray.BYTES_PER_ELEMENT) ); Atomics.wake(view, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/non-shared-bufferdatate-non-shared-int-views.js b/test/built-ins/Atomics/wake/non-shared-bufferdatate-non-shared-int-views.js
index 6b46aff513..86a96cbd1e 100644
--- a/test/built-ins/Atomics/wake/non-shared-bufferdatate-non-shared-int-views.js
+++ b/test/built-ins/Atomics/wake/non-shared-bufferdatate-non-shared-int-views.js
@@ -19,24 +19,24 @@ const poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Int16Array(nonsab), poisoned, poisoned);
-}, 'Atomics.wake(new Int16Array(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Int16Array(nonsab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Int8Array(nonsab), poisoned, poisoned);
-}, 'Atomics.wake(new Int8Array(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Int8Array(nonsab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint32Array(nonsab),  poisoned, poisoned);
-}, 'Atomics.wake(new Uint32Array(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Uint32Array(nonsab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint16Array(nonsab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint16Array(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Uint16Array(nonsab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint8Array(nonsab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint8Array(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Uint8Array(nonsab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint8ClampedArray(nonsab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint8ClampedArray(nonsab)) throws TypeError');
+}, '`Atomics.wake(new Uint8ClampedArray(nonsab), poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/non-shared-int-views.js b/test/built-ins/Atomics/wake/non-shared-int-views.js
index 04b901edd0..278a0762f2 100644
--- a/test/built-ins/Atomics/wake/non-shared-int-views.js
+++ b/test/built-ins/Atomics/wake/non-shared-int-views.js
@@ -19,24 +19,24 @@ const poisoned = {
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Int16Array(sab), poisoned, poisoned);
-}, 'Atomics.wake(new Int16Array(sab)) throws TypeError');
+}, '`Atomics.wake(new Int16Array(sab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Int8Array(sab), poisoned, poisoned);
-}, 'Atomics.wake(new Int8Array(sab)) throws TypeError');
+}, '`Atomics.wake(new Int8Array(sab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint32Array(sab),  poisoned, poisoned);
-}, 'Atomics.wake(new Uint32Array(sab)) throws TypeError');
+}, '`Atomics.wake(new Uint32Array(sab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint16Array(sab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint16Array(sab)) throws TypeError');
+}, '`Atomics.wake(new Uint16Array(sab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint8Array(sab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint8Array(sab)) throws TypeError');
+}, '`Atomics.wake(new Uint8Array(sab), poisoned, poisoned)` throws TypeError');
 
 assert.throws(TypeError, function() {
   Atomics.wake(new Uint8ClampedArray(sab), poisoned, poisoned);
-}, 'Atomics.wake(new Uint8ClampedArray(sab)) throws TypeError');
+}, '`Atomics.wake(new Uint8ClampedArray(sab), poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/null-bufferdata-throws.js b/test/built-ins/Atomics/wake/null-bufferdata-throws.js
index 3ee8e4e474..d81c76080b 100644
--- a/test/built-ins/Atomics/wake/null-bufferdata-throws.js
+++ b/test/built-ins/Atomics/wake/null-bufferdata-throws.js
@@ -34,4 +34,4 @@ try {
 
 assert.throws(TypeError, function() {
   Atomics.wake(i32a, poisoned, poisoned);
-}, 'Atomics.wake(i32a, poisoned, poisoned) on detached buffer throws TypeError');
+}, '`Atomics.wake(i32a, poisoned, poisoned)` throws TypeError');
diff --git a/test/built-ins/Atomics/wake/wake-all-on-loc.js b/test/built-ins/Atomics/wake/wake-all-on-loc.js
index 56136e4639..aa21761f3e 100644
--- a/test/built-ins/Atomics/wake/wake-all-on-loc.js
+++ b/test/built-ins/Atomics/wake/wake-all-on-loc.js
@@ -54,7 +54,7 @@ $262.agent.sleep(50);
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX),
   NUMAGENT,
-  'Atomics.wake(i32a, WAIT_INDEX) equals the value of `NUMAGENT` (3)'
+  'Atomics.wake(i32a, WAIT_INDEX) returns the value of `NUMAGENT` (3)'
 );
 
 const reports = [];
diff --git a/test/built-ins/Atomics/wake/wake-all.js b/test/built-ins/Atomics/wake/wake-all.js
index c2f88accfa..eda79a07ed 100644
--- a/test/built-ins/Atomics/wake/wake-all.js
+++ b/test/built-ins/Atomics/wake/wake-all.js
@@ -53,7 +53,7 @@ $262.agent.sleep(50);
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX),
   NUMAGENT,
-  'Atomics.wake(i32a, WAIT_INDEX) equals the value of `NUMAGENT` (3)'
+  'Atomics.wake(i32a, WAIT_INDEX) returns the value of `NUMAGENT` (3)'
 );
 
 const reports = [];
diff --git a/test/built-ins/Atomics/wake/wake-in-order-one-time.js b/test/built-ins/Atomics/wake/wake-in-order-one-time.js
index 59d11b5232..581b738457 100644
--- a/test/built-ins/Atomics/wake/wake-in-order-one-time.js
+++ b/test/built-ins/Atomics/wake/wake-in-order-one-time.js
@@ -49,39 +49,51 @@ $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
 $262.agent.sleep(50);
 
 var waiterlist = [];
-assert.sameValue(Atomics.store(i32a, SPIN + 0, 1), 1);
+assert.sameValue(
+  Atomics.store(i32a, SPIN + 0, 1),
+  1,
+  'Atomics.store(i32a, SPIN + 0, 1) returns 1'
+);
 waiterlist.push($262.agent.getReport());
 
-assert.sameValue(Atomics.store(i32a, SPIN + 1, 1), 1);
+assert.sameValue(
+  Atomics.store(i32a, SPIN + 1, 1),
+  1,
+  'Atomics.store(i32a, SPIN + 1, 1) returns 1'
+);
 waiterlist.push($262.agent.getReport());
 
-assert.sameValue(Atomics.store(i32a, SPIN + 2, 1), 1);
+assert.sameValue(
+  Atomics.store(i32a, SPIN + 2, 1),
+  1,
+  'Atomics.store(i32a, SPIN + 2, 1) returns 1'
+);
 waiterlist.push($262.agent.getReport());
 
 var notified = [];
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX, 1),
   1,
-  `Notification #0: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+  'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
 );
 notified.push($262.agent.getReport());
 
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX, 1),
   1,
-  `Notification #1: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+  'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
 );
 notified.push($262.agent.getReport());
 
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX, 1),
   1,
-  `Notification #2: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+  'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
 );
 notified.push($262.agent.getReport());
 
 assert.sameValue(
   notified.join(''),
   waiterlist.join(''),
-  `notified and waiterlist order do not match.`
+  'notified.join(\'\') returns waiterlist.join(\'\')'
 );
diff --git a/test/built-ins/Atomics/wake/wake-in-order.js b/test/built-ins/Atomics/wake/wake-in-order.js
index 3a2700ff35..a5de6b8341 100644
--- a/test/built-ins/Atomics/wake/wake-in-order.js
+++ b/test/built-ins/Atomics/wake/wake-in-order.js
@@ -50,40 +50,52 @@ for (var attempt = 0; attempt < 10; attempt++) {
   $262.agent.sleep(50);
 
   var waiterlist = [];
-  assert.sameValue(Atomics.store(i32a, SPIN + 0, 1), 1);
+  assert.sameValue(
+    Atomics.store(i32a, SPIN + 0, 1),
+    1,
+    'Atomics.store(i32a, SPIN + 0, 1) returns 1'
+  );
   waiterlist.push($262.agent.getReport());
 
-  assert.sameValue(Atomics.store(i32a, SPIN + 1, 1), 1);
+  assert.sameValue(
+    Atomics.store(i32a, SPIN + 1, 1),
+    1,
+    'Atomics.store(i32a, SPIN + 1, 1) returns 1'
+  );
   waiterlist.push($262.agent.getReport());
 
-  assert.sameValue(Atomics.store(i32a, SPIN + 2, 1), 1);
+  assert.sameValue(
+    Atomics.store(i32a, SPIN + 2, 1),
+    1,
+    'Atomics.store(i32a, SPIN + 2, 1) returns 1'
+  );
   waiterlist.push($262.agent.getReport());
 
   var notified = [];
   assert.sameValue(
     Atomics.wake(i32a, WAIT_INDEX, 1),
     1,
-    `Attempt #${attempt}, Notification #0: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+    'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
   );
   notified.push($262.agent.getReport());
 
   assert.sameValue(
     Atomics.wake(i32a, WAIT_INDEX, 1),
     1,
-    `Attempt #${attempt}, Notification #1: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+    'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
   );
   notified.push($262.agent.getReport());
 
   assert.sameValue(
     Atomics.wake(i32a, WAIT_INDEX, 1),
     1,
-    `Attempt #${attempt}, Notification #2: on WAIT_INDEX (0) of i32a must notify 1 waiter.`
+    'Atomics.wake(i32a, WAIT_INDEX, 1) returns 1'
   );
   notified.push($262.agent.getReport());
 
   assert.sameValue(
     notified.join(''),
     waiterlist.join(''),
-    `Attempt #${attempt}: notified and waiterlist order do not match.`
+    'notified.join(\'\') returns waiterlist.join(\'\')'
   );
 }
diff --git a/test/built-ins/Atomics/wake/wake-nan.js b/test/built-ins/Atomics/wake/wake-nan.js
index e4a0471565..7d1e76012a 100644
--- a/test/built-ins/Atomics/wake/wake-nan.js
+++ b/test/built-ins/Atomics/wake/wake-nan.js
@@ -23,7 +23,7 @@ const i32a = new Int32Array(
 
 $262.agent.broadcast(i32a.buffer);
 $262.agent.sleep(10); // Give the agent a chance to wait
-assert.sameValue(Atomics.wake(i32a, 0, NaN), 0, 'Atomics.wake(i32a, 0, NaN) returns 0, and will not actually notify any waiters.');
+assert.sameValue(Atomics.wake(i32a, 0, NaN), 0, 'Atomics.wake(i32a, 0, NaN) returns 0');
 
 // Sleep past the timeout
 $262.agent.sleep(300);
diff --git a/test/built-ins/Atomics/wake/wake-one.js b/test/built-ins/Atomics/wake/wake-one.js
index bbf3507bfb..5d6498a477 100644
--- a/test/built-ins/Atomics/wake/wake-one.js
+++ b/test/built-ins/Atomics/wake/wake-one.js
@@ -46,7 +46,7 @@ $262.agent.sleep(10);
 assert.sameValue(
   Atomics.wake(i32a, 0, WAKECOUNT),
   WAKECOUNT,
-  'Atomics.wake(i32a, 0, WAKECOUNT) equals the value of `WAKECOUNT` (1)'
+  'Atomics.wake(i32a, 0, WAKECOUNT) returns the value of `WAKECOUNT` (1)'
 );
 
 // Collect and check results
diff --git a/test/built-ins/Atomics/wake/wake-rewake-noop.js b/test/built-ins/Atomics/wake/wake-rewake-noop.js
index 086b2ea736..59080e8f4b 100644
--- a/test/built-ins/Atomics/wake/wake-rewake-noop.js
+++ b/test/built-ins/Atomics/wake/wake-rewake-noop.js
@@ -28,7 +28,7 @@ $262.agent.waitUntil(i32a, 1, 1);
 
 assert.sameValue(Atomics.wake(i32a, 0, 1), 1, 'Atomics.wake(i32a, 0, 1) returns 1');
 
-assert.sameValue($262.agent.getReport(), 'ok', 'The value of `report` is "ok"');
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
 
 // Already awake, this should be a noop
 assert.sameValue(Atomics.wake(i32a, 0, 1), 0, 'Atomics.wake(i32a, 0, 1) returns 0');
diff --git a/test/built-ins/Atomics/wake/wake-two.js b/test/built-ins/Atomics/wake/wake-two.js
index 7a05ba188d..f318bac1f1 100644
--- a/test/built-ins/Atomics/wake/wake-two.js
+++ b/test/built-ins/Atomics/wake/wake-two.js
@@ -47,7 +47,7 @@ $262.agent.sleep(10);
 assert.sameValue(
   Atomics.wake(i32a, 0, WAKECOUNT),
   WAKECOUNT,
-  'Atomics.wake(i32a, 0, WAKECOUNT) equals the value of `WAKECOUNT` (2)'
+  'Atomics.wake(i32a, 0, WAKECOUNT) returns the value of `WAKECOUNT` (2)'
 );
 
 // Sleep past the timeout
diff --git a/test/built-ins/Atomics/wake/wake-zero.js b/test/built-ins/Atomics/wake/wake-zero.js
index df226e98ed..85eea4fa11 100644
--- a/test/built-ins/Atomics/wake/wake-zero.js
+++ b/test/built-ins/Atomics/wake/wake-zero.js
@@ -42,12 +42,12 @@ $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
 assert.sameValue(
   Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT),
   WAKECOUNT,
-  'Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT) equals the value of `WAKECOUNT` (0)'
+  'Atomics.wake(i32a, WAIT_INDEX, WAKECOUNT) returns the value of `WAKECOUNT` (0)'
 );
 
 // Sleep past the timeout
 $262.agent.sleep(300);
 
 for (var i = 0; i < NUMAGENT; i++) {
-  assert.sameValue($262.agent.getReport(), 'timed-out', `Report #${i}: must equal "timed-out"`);
+  assert.sameValue($262.agent.getReport(), 'timed-out', '$262.agent.getReport() returns "timed-out"');
 }
diff --git a/test/built-ins/Atomics/xor/bad-range.js b/test/built-ins/Atomics/xor/bad-range.js
index fd5858533b..49b0c94fc5 100644
--- a/test/built-ins/Atomics/xor/bad-range.js
+++ b/test/built-ins/Atomics/xor/bad-range.js
@@ -17,6 +17,6 @@ testWithTypedArrayConstructors(function(TA) {
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.xor(view, IdxGen(view), 0);
-    }, 'Atomics.xor(view, IdxGen(view), 0) throws RangeError');
+    }, '`Atomics.xor(view, IdxGen(view), 0)` throws RangeError');
   });
 }, views);
diff --git a/test/built-ins/Atomics/xor/bigint/bad-range.js b/test/built-ins/Atomics/xor/bigint/bad-range.js
index c2b1c3b574..0cf4eb6269 100644
--- a/test/built-ins/Atomics/xor/bigint/bad-range.js
+++ b/test/built-ins/Atomics/xor/bigint/bad-range.js
@@ -16,6 +16,6 @@ testWithBigIntTypedArrayConstructors(function(TA) {
   testWithAtomicsOutOfBoundsIndices(function(IdxGen) {
     assert.throws(RangeError, function() {
       Atomics.xor(view, IdxGen(view), 10);
-    }, 'Atomics.xor(view, IdxGen(view), 10) throws RangeError');
+    }, '`Atomics.xor(view, IdxGen(view), 10)` throws RangeError');
   });
 });
diff --git a/test/built-ins/Atomics/xor/bigint/good-views.js b/test/built-ins/Atomics/xor/bigint/good-views.js
index b0f5159f5c..242a1f1b62 100644
--- a/test/built-ins/Atomics/xor/bigint/good-views.js
+++ b/test/built-ins/Atomics/xor/bigint/good-views.js
@@ -1,61 +1,102 @@
 // Copyright (C) 2018 Rick Waldron. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
 esid: sec-atomics.xor
 description: Test Atomics.xor on arrays that allow atomic operations
 includes: [testAtomics.js, testBigIntTypedArray.js]
 features: [ArrayBuffer, arrow-function, Atomics, BigInt, DataView, for-of, let, SharedArrayBuffer, TypedArray]
 ---*/
-
-var sab = new SharedArrayBuffer(1024);
-var ab = new ArrayBuffer(16);
+// Make it interesting - use non-zero byteOffsets and non-zero indexes.
+// And again
+// In-bounds boundary cases for indexing
+// Atomics.store() computes an index from Idx in the same way as other
+// Atomics operations, not quite like view[Idx].
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
 
 testWithBigIntTypedArrayConstructors(function(TA) {
-  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
-
-  var view = new TA(sab, 32, 20);
-  var control = new TA(ab, 0, 2);
-
-  view[8] = 0x33333333;
-  control[0] = 0x33333333;
-  assert.sameValue(Atomics.xor(view, 8, 0x55555555), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 0x66666666;
-  assert.sameValue(view[8], control[0]);
-  assert.sameValue(Atomics.xor(view, 8, 0xF0F0F0F0), control[0],
-    "Result is subject to chopping");
-
-  control[0] = 0x96969696;
-  assert.sameValue(view[8], control[0]);
-
-  view[3] = -5;
-  control[0] = -5;
-  assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
-  assert.sameValue(view[3], control[0]);
-
-  control[0] = 12345;
-  view[3] = 12345;
-  assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
-
-  // And again
-  control[0] = 123456789;
-  view[3] = 123456789;
-  assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
-
-  // In-bounds boundary cases for indexing
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+  view[8] = 0x33333333n;
+  control[0] = 0x33333333n;
+
+  assert.sameValue(
+    Atomics.xor(view, 8, 0x55555555n),
+    control[0],
+    'Atomics.xor(view, 8, 0x55555555n) returns the value of `control[0]` (0x33333333n)'
+  );
+
+  control[0] = 0x66666666n;
+
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x66666666n)'
+  );
+
+  assert.sameValue(
+    Atomics.xor(view, 8, 0xF0F0F0F0),
+    control[0],
+    'Atomics.xor(view, 8, 0xF0F0F0F0) returns the value of `control[0]` (0x66666666n)'
+  );
+
+  control[0] = 0x96969696n;
+
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x96969696n)'
+  );
+
+  view[3] = -5n;
+  control[0] = -5n;
+
+  assert.sameValue(
+    Atomics.xor(view, 3, 0n),
+    control[0],
+    'Atomics.xor(view, 3, 0n) returns the value of `control[0]` (-5n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (-5n)'
+  );
+
+  control[0] = 12345n;
+  view[3] = 12345n;
+
+  assert.sameValue(
+    Atomics.xor(view, 3, 0n),
+    control[0],
+    'Atomics.xor(view, 3, 0n) returns the value of `control[0]` (12345n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (12345n)'
+  );
+
+  control[0] = 123456789n;
+  view[3] = 123456789n;
+
+  assert.sameValue(
+    Atomics.xor(view, 3, 0n),
+    control[0],
+    'Atomics.xor(view, 3, 0n) returns the value of `control[0]` (123456789n)'
+  );
+
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (123456789n)'
+  );
+
   testWithAtomicsInBoundsIndices(function(IdxGen) {
     let Idx = IdxGen(view);
-    view.fill(0);
-    // Atomics.store() computes an index from Idx in the same way as other
-    // Atomics operations, not quite like view[Idx].
-    Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.xor(view, Idx, 0), 37);
+    view.fill(0n);
+    Atomics.store(view, Idx, 37n);
+    assert.sameValue(Atomics.xor(view, Idx, 0n), 37n, 'Atomics.xor(view, Idx, 0n) returns 37n');
   });
-});
+});
\ No newline at end of file
diff --git a/test/built-ins/Atomics/xor/bigint/nonshared-int-views.js b/test/built-ins/Atomics/xor/bigint/nonshared-int-views.js
index 3648a8e3df..87a9661a73 100644
--- a/test/built-ins/Atomics/xor/bigint/nonshared-int-views.js
+++ b/test/built-ins/Atomics/xor/bigint/nonshared-int-views.js
@@ -14,5 +14,5 @@ var buffer = new ArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 4);
 testWithBigIntTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.xor(new TA(buffer), 0, 0);
-  }, 'Atomics.xor(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.xor(new TA(buffer), 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/xor/expected-return-value.js b/test/built-ins/Atomics/xor/expected-return-value.js
index d275d46658..424b67d66f 100644
--- a/test/built-ins/Atomics/xor/expected-return-value.js
+++ b/test/built-ins/Atomics/xor/expected-return-value.js
@@ -27,12 +27,20 @@ info: |
 features: [Atomics, SharedArrayBuffer, TypedArray]
 ---*/
 
-var buffer = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4);
-var i32a = new Int32Array(buffer);
-var initial = 0b00000001000000001000000010000001;
-var update = 0b00000001111111111000000011111111;
 
-i32a[0] = initial;
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+const a = 0b00000001000000001000000010000001;
+const b = 0b00000001111111111000000011111111;
+const c = 0b00000000111111110000000001111110;
 
-assert.sameValue(Atomics.xor(i32a, 0, update), initial);
-assert.sameValue(i32a[0], initial ^ update);
+i32a[0] = a;
+
+assert.sameValue(
+  Atomics.xor(i32a, 0, b),
+  a,
+  'Atomics.xor(i32a, 0, b) returns the value of `a` (0b00000001000000001000000010000001)'
+);
+
+assert.sameValue(i32a[0], c, 'The value of i32a[0] equals the value of `c` (0b00000000111111110000000001111110)');
diff --git a/test/built-ins/Atomics/xor/good-views.js b/test/built-ins/Atomics/xor/good-views.js
index 76be431af4..ba5c582532 100644
--- a/test/built-ins/Atomics/xor/good-views.js
+++ b/test/built-ins/Atomics/xor/good-views.js
@@ -21,34 +21,54 @@ testWithTypedArrayConstructors(function(TA) {
   view[8] = 0x33333333;
   control[0] = 0x33333333;
   assert.sameValue(Atomics.xor(view, 8, 0x55555555), control[0],
-    "Result is subject to chopping");
+    'Atomics.xor(view, 8, 0x55555555) returns the value of `control[0]` (0x33333333)');
 
   control[0] = 0x66666666;
-  assert.sameValue(view[8], control[0]);
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x66666666)'
+  );
   assert.sameValue(Atomics.xor(view, 8, 0xF0F0F0F0), control[0],
-    "Result is subject to chopping");
+    'Atomics.xor(view, 8, 0xF0F0F0F0) returns the value of `control[0]` (0x66666666)');
 
   control[0] = 0x96969696;
-  assert.sameValue(view[8], control[0]);
+  assert.sameValue(
+    view[8],
+    control[0],
+    'The value of view[8] equals the value of `control[0]` (0x96969696)'
+  );
 
   view[3] = -5;
   control[0] = -5;
   assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is negative and subject to coercion");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.xor(view, 3, 0) returns the value of `control[0]` (-5)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (-5)'
+  );
 
   control[0] = 12345;
   view[3] = 12345;
   assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.xor(view, 3, 0) returns the value of `control[0]` (12345)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (12345)'
+  );
 
   // And again
   control[0] = 123456789;
   view[3] = 123456789;
   assert.sameValue(Atomics.xor(view, 3, 0), control[0],
-    "Result is subject to chopping");
-  assert.sameValue(view[3], control[0]);
+    'Atomics.xor(view, 3, 0) returns the value of `control[0]` (123456789)');
+  assert.sameValue(
+    view[3],
+    control[0],
+    'The value of view[3] equals the value of `control[0]` (123456789)'
+  );
 
   // In-bounds boundary cases for indexing
   testWithAtomicsInBoundsIndices(function(IdxGen) {
@@ -57,6 +77,6 @@ testWithTypedArrayConstructors(function(TA) {
     // Atomics.store() computes an index from Idx in the same way as other
     // Atomics operations, not quite like view[Idx].
     Atomics.store(view, Idx, 37);
-    assert.sameValue(Atomics.xor(view, Idx, 0), 37);
+    assert.sameValue(Atomics.xor(view, Idx, 0), 37, 'Atomics.xor(view, Idx, 0) returns 37');
   });
 }, views);
diff --git a/test/built-ins/Atomics/xor/non-views.js b/test/built-ins/Atomics/xor/non-views.js
index b328f70001..27963e3f80 100644
--- a/test/built-ins/Atomics/xor/non-views.js
+++ b/test/built-ins/Atomics/xor/non-views.js
@@ -12,5 +12,5 @@ features: [ArrayBuffer, arrow-function, Atomics, DataView, for-of, let, SharedAr
 testWithAtomicsNonViewValues(function(view) {
   assert.throws(TypeError, function() {
     Atomics.xor(view, 0, 0);
-  }, 'Atomics.xor(view, 0, 0) throws TypeError');
+  }, '`Atomics.xor(view, 0, 0)` throws TypeError');
 });
diff --git a/test/built-ins/Atomics/xor/nonshared-int-views.js b/test/built-ins/Atomics/xor/nonshared-int-views.js
index 8be4b2d7bc..7444786027 100644
--- a/test/built-ins/Atomics/xor/nonshared-int-views.js
+++ b/test/built-ins/Atomics/xor/nonshared-int-views.js
@@ -15,5 +15,5 @@ var views = intArrayConstructors.slice();
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.xor(new TA(buffer), 0, 0);
-  }, 'Atomics.xor(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.xor(new TA(buffer), 0, 0)` throws TypeError');
 }, views);
diff --git a/test/built-ins/Atomics/xor/shared-nonint-views.js b/test/built-ins/Atomics/xor/shared-nonint-views.js
index 845d459a94..13b246634e 100644
--- a/test/built-ins/Atomics/xor/shared-nonint-views.js
+++ b/test/built-ins/Atomics/xor/shared-nonint-views.js
@@ -14,5 +14,5 @@ var buffer = new SharedArrayBuffer(1024);
 testWithTypedArrayConstructors(function(TA) {
   assert.throws(TypeError, function() {
     Atomics.xor(new TA(buffer), 0, 0);
-  }, 'Atomics.xor(new TA(buffer), 0, 0) throws TypeError');
+  }, '`Atomics.xor(new TA(buffer), 0, 0)` throws TypeError');
 }, floatArrayConstructors);
-- 
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