diff --git a/features.txt b/features.txt
index 478e419365201b7e06289a52dbcc5f45bf509616..07d42907ecf98e7e6ef4bd6826e947f74b907643 100644
--- a/features.txt
+++ b/features.txt
@@ -7,6 +7,10 @@
#
# https://github.com/tc39/process-document
+# Object.fromEntries
+# https://github.com/tc39/proposal-object-from-entries
+Object.fromEntries
+
# BigInt
# https://github.com/tc39/proposal-bigint
BigInt
diff --git a/test/built-ins/Object/fromEntries/evaluation-order.js b/test/built-ins/Object/fromEntries/evaluation-order.js
new file mode 100644
index 0000000000000000000000000000000000000000..4c9e07a4cb4ec1e74ea30dc7ab44bd2a8eac21ed
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/evaluation-order.js
@@ -0,0 +1,74 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Evaluation order is iterator.next(), get '0', get '1', toPropertyKey, repeat.
+esid: sec-object.fromentries
+includes: [compareArray.js]
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var effects = [];
+
+function makeEntry(label) {
+ return {
+ get '0'() {
+ effects.push('access property "0" of ' + label + ' entry');
+ return {
+ toString: function() {
+ effects.push('toString of ' + label + ' key');
+ return label + ' key';
+ },
+ };
+ },
+ get '1'() {
+ effects.push('access property "1" of ' + label + ' entry');
+ return label + ' value';
+ },
+ };
+}
+
+var iterable = {
+ [Symbol.iterator]: function() {
+ effects.push('get Symbol.iterator');
+ var count = 0;
+ return {
+ next: function() {
+ effects.push('next ' + count);
+ if (count === 0) {
+ ++count;
+ return {
+ done: false,
+ value: makeEntry('first', 'first key', 'first value'),
+ };
+ } else if (count === 1) {
+ ++count;
+ return {
+ done: false,
+ value: makeEntry('second', 'second key', 'second value'),
+ };
+ } else {
+ return {
+ done: true,
+ };
+ }
+ },
+ };
+ },
+};
+
+var result = Object.fromEntries(iterable);
+assert.compareArray(effects, [
+ 'get Symbol.iterator',
+ 'next 0',
+ 'access property "0" of first entry',
+ 'access property "1" of first entry',
+ 'toString of first key',
+ 'next 1',
+ 'access property "0" of second entry',
+ 'access property "1" of second entry',
+ 'toString of second key',
+ 'next 2',
+], 'Object.fromEntries evaluation order');
+assert.sameValue(result['first key'], 'first value');
+assert.sameValue(result['second key'], 'second value');
diff --git a/test/built-ins/Object/fromEntries/iterator-closed-for-null-entry.js.js b/test/built-ins/Object/fromEntries/iterator-closed-for-null-entry.js.js
new file mode 100644
index 0000000000000000000000000000000000000000..b84d87feacd2e86ca15498aea131df38b98383bb
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-closed-for-null-entry.js.js
@@ -0,0 +1,39 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Closes iterators when they return entries which are null.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var returned = false;
+var iterable = {
+ [Symbol.iterator]: function() {
+ var advanced = false;
+ return {
+ next: function() {
+ if (advanced) {
+ throw new Test262Error('should only advance once');
+ }
+ advanced = true;
+ return {
+ done: false,
+ value: 'null',
+ };
+ },
+ return: function() {
+ if (returned) {
+ throw new Test262Error('should only return once');
+ }
+ returned = true;
+ },
+ };
+ },
+};
+
+assert.throws(TypeError, function() {
+ Object.fromEntries(iterable);
+});
+
+assert(returned, 'iterator should be closed when entry is null');
diff --git a/test/built-ins/Object/fromEntries/iterator-closed-for-string-entry.js.js b/test/built-ins/Object/fromEntries/iterator-closed-for-string-entry.js.js
new file mode 100644
index 0000000000000000000000000000000000000000..b0c5bc9f9098be28cda26f0d9408803e0cb7f2e8
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-closed-for-string-entry.js.js
@@ -0,0 +1,39 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Closes iterators when they return entries which are strings.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var returned = false;
+var iterable = {
+ [Symbol.iterator]: function() {
+ var advanced = false;
+ return {
+ next: function() {
+ if (advanced) {
+ throw new Test262Error('should only advance once');
+ }
+ advanced = true;
+ return {
+ done: false,
+ value: 'ab',
+ };
+ },
+ return: function() {
+ if (returned) {
+ throw new Test262Error('should only return once');
+ }
+ returned = true;
+ },
+ };
+ },
+};
+
+assert.throws(TypeError, function() {
+ Object.fromEntries(iterable);
+});
+
+assert(returned, 'iterator should be closed when entry is a string');
diff --git a/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-accessor.js b/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-accessor.js
new file mode 100644
index 0000000000000000000000000000000000000000..9e7f9e4a2cfa961f51954c6c45305b73425aad55
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-accessor.js
@@ -0,0 +1,45 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Closes iterators when accessing an entry's properties throws.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+function DummyError() {}
+
+var returned = false;
+var iterable = {
+ [Symbol.iterator]: function() {
+ var advanced = false;
+ return {
+ next: function() {
+ if (advanced) {
+ throw new Test262Error('should only advance once');
+ }
+ advanced = true;
+ return {
+ done: false,
+ value: {
+ get '0'() {
+ throw new DummyError();
+ },
+ },
+ };
+ },
+ return: function() {
+ if (returned) {
+ throw new Test262Error('should only return once');
+ }
+ returned = true;
+ },
+ };
+ },
+};
+
+assert.throws(DummyError, function() {
+ Object.fromEntries(iterable);
+});
+
+assert(returned, 'iterator should be closed when entry property access throws');
diff --git a/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-key-tostring.js b/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-key-tostring.js
new file mode 100644
index 0000000000000000000000000000000000000000..5a845b5b20657e87394db529b023b099d88561ec
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-closed-for-throwing-entry-key-tostring.js
@@ -0,0 +1,47 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Closes iterators when toString on a key throws.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+function DummyError() {}
+
+var returned = false;
+var iterable = {
+ [Symbol.iterator]: function() {
+ var advanced = false;
+ return {
+ next: function() {
+ if (advanced) {
+ throw new Test262Error('should only advance once');
+ }
+ advanced = true;
+ return {
+ done: false,
+ value: {
+ 0: {
+ toString: function() {
+ throw new DummyError();
+ },
+ },
+ },
+ };
+ },
+ return: function() {
+ if (returned) {
+ throw new Test262Error('should only return once');
+ }
+ returned = true;
+ },
+ };
+ },
+};
+
+assert.throws(DummyError, function() {
+ Object.fromEntries(iterable);
+});
+
+assert(returned, 'iterator should be closed when key toString throws');
diff --git a/test/built-ins/Object/fromEntries/iterator-not-closed-for-next-returning-non-object.js b/test/built-ins/Object/fromEntries/iterator-not-closed-for-next-returning-non-object.js
new file mode 100644
index 0000000000000000000000000000000000000000..8f18c974f04f70af3e235c14515ee69ca8ed6bbd
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-not-closed-for-next-returning-non-object.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Does not close iterators with a `next` method which returns a non-object.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var iterable = {
+ [Symbol.iterator]: function() {
+ return {
+ next: function() {
+ return null;
+ },
+ return: function() {
+ throw new Test262Error('should not call return');
+ },
+ };
+ },
+};
+
+assert.throws(TypeError, function() {
+ Object.fromEntries(iterable);
+});
diff --git a/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-done-accessor.js b/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-done-accessor.js
new file mode 100644
index 0000000000000000000000000000000000000000..5fd69c116f06e051e38e59a70fd133f1d149118f
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-done-accessor.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Does not close iterators with a `done` accessor which throws.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+function DummyError() {}
+
+var returned = false;
+var iterable = {
+ [Symbol.iterator]: function() {
+ return {
+ next: function() {
+ return {
+ get done() {
+ throw new DummyError();
+ },
+ };
+ },
+ return: function() {
+ throw new Test262Error('should not call return');
+ },
+ };
+ },
+};
+
+assert.throws(DummyError, function() {
+ Object.fromEntries(iterable);
+});
diff --git a/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-next.js b/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-next.js
new file mode 100644
index 0000000000000000000000000000000000000000..b5ebcdf3f1505d5c458e5f9cdf9d0e1818d542c6
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-not-closed-for-throwing-next.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Does not close iterators with a `next` method which throws.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+function DummyError() {}
+
+var iterable = {
+ [Symbol.iterator]: function() {
+ return {
+ next: function() {
+ throw new DummyError();
+ },
+ return: function() {
+ throw new Test262Error('should not call return');
+ },
+ };
+ },
+};
+
+assert.throws(DummyError, function() {
+ Object.fromEntries(iterable);
+});
diff --git a/test/built-ins/Object/fromEntries/iterator-not-closed-for-uncallable-next.js b/test/built-ins/Object/fromEntries/iterator-not-closed-for-uncallable-next.js
new file mode 100644
index 0000000000000000000000000000000000000000..f9aa9d23e1038c99d3ef008d2a5a63b9c58da5a9
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/iterator-not-closed-for-uncallable-next.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Does not close iterators with an uncallable `next` property.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var iterable = {
+ [Symbol.iterator]: function() {
+ return {
+ next: null,
+ return: function() {
+ throw new Test262Error('should not call return');
+ },
+ };
+ },
+};
+
+assert.throws(TypeError, function() {
+ Object.fromEntries(iterable);
+});
diff --git a/test/built-ins/Object/fromEntries/key-order.js b/test/built-ins/Object/fromEntries/key-order.js
new file mode 100644
index 0000000000000000000000000000000000000000..f8a08d3fae84d0c05a1ab9b954570cedf9a44098
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/key-order.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Key enumeration order of result objects matches the order of entries in the iterable.
+esid: sec-object.fromentries
+includes: [compareArray.js]
+features: [Object.fromEntries]
+---*/
+
+var entries = [
+ ['z', 1],
+ ['y', 2],
+ ['x', 3],
+ ['y', 4],
+];
+
+var result = Object.fromEntries(entries);
+assert.sameValue(result['z'], 1);
+assert.sameValue(result['y'], 4);
+assert.sameValue(result['x'], 3);
+assert.compareArray(Object.keys(result), ['z', 'y', 'x']);
diff --git a/test/built-ins/Object/fromEntries/length.js b/test/built-ins/Object/fromEntries/length.js
new file mode 100644
index 0000000000000000000000000000000000000000..56615b4d7b8d0e20a6078018fa5ab531d874ee6a
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/length.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Object.fromEntries.length is 1.
+esid: sec-object.fromentries
+includes: [propertyHelper.js]
+features: [Object.fromEntries]
+---*/
+
+assert.sameValue(Object.fromEntries.length, 1);
+
+verifyNotEnumerable(Object.fromEntries, "length");
+verifyNotWritable(Object.fromEntries, "length");
+verifyConfigurable(Object.fromEntries, "length");
diff --git a/test/built-ins/Object/fromEntries/name.js b/test/built-ins/Object/fromEntries/name.js
new file mode 100644
index 0000000000000000000000000000000000000000..aa39c2277dd419de14d6b0d797cb67fb94c3e040
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/name.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Object.fromEntries.name is "fromEntries".
+esid: sec-object.fromentries
+includes: [propertyHelper.js]
+features: [Object.fromEntries]
+---*/
+
+assert.sameValue(Object.fromEntries.name, "fromEntries");
+
+verifyNotEnumerable(Object.fromEntries, "name");
+verifyNotWritable(Object.fromEntries, "name");
+verifyConfigurable(Object.fromEntries, "name");
diff --git a/test/built-ins/Object/fromEntries/requires-argument.js b/test/built-ins/Object/fromEntries/requires-argument.js
new file mode 100644
index 0000000000000000000000000000000000000000..b65051b00395fc9cea98f317fd3707f2ba142308
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/requires-argument.js
@@ -0,0 +1,12 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Throws when called without an argument.
+esid: sec-object.fromentries
+features: [Object.fromEntries]
+---*/
+
+assert.throws(TypeError, function() {
+ Object.fromEntries();
+});
diff --git a/test/built-ins/Object/fromEntries/simple-properties.js b/test/built-ins/Object/fromEntries/simple-properties.js
new file mode 100644
index 0000000000000000000000000000000000000000..92663304bafb1d4430a715c72e6876fe95d0ed1b
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/simple-properties.js
@@ -0,0 +1,14 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Creates data properties which are enumerable, writable, and configurable.
+esid: sec-object.fromentries
+includes: [propertyHelper.js]
+features: [Object.fromEntries]
+---*/
+
+var result = Object.fromEntries([['key', 'value']]);
+verifyEnumerable(result, 'key');
+verifyWritable(result, 'key');
+verifyConfigurable(result, 'key');
diff --git a/test/built-ins/Object/fromEntries/string-entry-object-succeeds.js b/test/built-ins/Object/fromEntries/string-entry-object-succeeds.js
new file mode 100644
index 0000000000000000000000000000000000000000..d616f4d47a02c22204d84493c41ce0dc8e973b4f
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/string-entry-object-succeeds.js
@@ -0,0 +1,11 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Succeeds when an entry object is a boxed string.
+esid: sec-object.fromentries
+features: [Object.fromEntries]
+---*/
+
+var result = Object.fromEntries([Object('ab')]);
+assert.sameValue(result['a'], 'b');
diff --git a/test/built-ins/Object/fromEntries/string-entry-primitive-throws.js b/test/built-ins/Object/fromEntries/string-entry-primitive-throws.js
new file mode 100644
index 0000000000000000000000000000000000000000..2a678e3d8aafb340924756daa1e8fb1e7ded4284
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/string-entry-primitive-throws.js
@@ -0,0 +1,12 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Throws when an entry object is a primitive string.
+esid: sec-object.fromentries
+features: [Object.fromEntries]
+---*/
+
+assert.throws(TypeError, function() {
+ Object.fromEntries(['ab']);
+});
diff --git a/test/built-ins/Object/fromEntries/supports-symbols.js b/test/built-ins/Object/fromEntries/supports-symbols.js
new file mode 100644
index 0000000000000000000000000000000000000000..fc729961664ee49b195cc01c4a68bb77210cd8ec
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/supports-symbols.js
@@ -0,0 +1,12 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Allows symbol keys.
+esid: sec-object.fromentries
+features: [Symbol, Object.fromEntries]
+---*/
+
+var key = Symbol();
+var result = Object.fromEntries([[key, 'value']]);
+assert.sameValue(result[key], 'value');
diff --git a/test/built-ins/Object/fromEntries/to-property-key.js b/test/built-ins/Object/fromEntries/to-property-key.js
new file mode 100644
index 0000000000000000000000000000000000000000..a707787588804fd6ee98fbf3ca77f0147af73a65
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/to-property-key.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Coerces keys to strings using ToPropertyKey.
+esid: sec-object.fromentries
+features: [Symbol.toPrimitive, Object.fromEntries]
+---*/
+
+var key = {
+ [Symbol.toPrimitive]: function(hint) {
+ assert.sameValue(hint, 'string');
+ return 'key';
+ },
+};
+var result = Object.fromEntries([[key, 'value']]);
+assert.sameValue(result.key, 'value');
diff --git a/test/built-ins/Object/fromEntries/uses-define-semantics.js b/test/built-ins/Object/fromEntries/uses-define-semantics.js
new file mode 100644
index 0000000000000000000000000000000000000000..b5f56686d1f79865750e4a3841e5a250286a75d1
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/uses-define-semantics.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Uses [[DefineOwnProperty]] rather than [[Set]].
+esid: sec-object.fromentries
+features: [Object.fromEntries]
+---*/
+
+Object.defineProperty(Object.prototype, 'property', {
+ get: function() {
+ throw new Test262Error('should not trigger getter on Object.prototype');
+ },
+ set: function() {
+ throw new Test262Error('should not trigger setter on Object.prototype');
+ },
+});
+
+var result = Object.fromEntries([['property', 'value']]);
+assert.sameValue(result['property'], 'value', '');
diff --git a/test/built-ins/Object/fromEntries/uses-keys-not-iterator.js b/test/built-ins/Object/fromEntries/uses-keys-not-iterator.js
new file mode 100644
index 0000000000000000000000000000000000000000..c4302074cb0c5171647b7489d065983fc115b621
--- /dev/null
+++ b/test/built-ins/Object/fromEntries/uses-keys-not-iterator.js
@@ -0,0 +1,48 @@
+// Copyright (C) 2018 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Reads properties rather than iterating.
+esid: sec-object.fromentries
+features: [Symbol.iterator, Object.fromEntries]
+---*/
+
+var iterable = {
+ [Symbol.iterator]: function() {
+ var count = 0;
+ return {
+ next: function() {
+ if (count === 0) {
+ ++count;
+ return {
+ done: false,
+ value: {
+ '0': 'first key',
+ '1': 'first value',
+ get [Symbol.iterator]() {
+ throw new Test262Error('Object.fromEntries should not access Symbol.iterator on entry objects');
+ },
+ },
+ };
+ } else if (count === 1) {
+ ++count;
+ Array.prototype[Symbol.iterator] = function() {
+ throw new Test262Error('Object.fromEntries should not access Symbol.iterator on entry arrays');
+ };
+ return {
+ done: false,
+ value: ['second key', 'second value'],
+ };
+ } else {
+ return {
+ done: true,
+ };
+ }
+ },
+ };
+ },
+};
+
+var result = Object.fromEntries(iterable);
+assert.sameValue(result['first key'], 'first value');
+assert.sameValue(result['second key'], 'second value');