diff --git a/test/built-ins/Array/from/get-iter-method-err.js b/test/built-ins/Array/from/get-iter-method-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..745f1081358ebd06c79a434d7b5a674f3f6ace43
--- /dev/null
+++ b/test/built-ins/Array/from/get-iter-method-err.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error accessing items' `Symbol.iterator` attribute
+info: >
+ [...]
+ 4. Let usingIterator be GetMethod(items, @@iterator).
+ 5. ReturnIfAbrupt(usingIterator).
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+Object.defineProperty(items, Symbol.iterator, {
+ get: function() {
+ throw new Test262Error();
+ }
+});
+
+assert.throws(Test262Error, function() {
+ Array.from(items);
+});
diff --git a/test/built-ins/Array/from/iter-adv-err.js b/test/built-ins/Array/from/iter-adv-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..0b8259baebcb831ebb1de21c36bf783808ad504c
--- /dev/null
+++ b/test/built-ins/Array/from/iter-adv-err.js
@@ -0,0 +1,28 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error advancing iterator
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ i. Let Pk be ToString(k).
+ ii. Let next be IteratorStep(iterator).
+ iii. ReturnIfAbrupt(next).
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ throw new Test262Error();
+ }
+ };
+};
+
+assert.throws(Test262Error, function() {
+ Array.from(items);
+});
diff --git a/test/built-ins/Array/from/iter-cstm-ctor-err.js b/test/built-ins/Array/from/iter-cstm-ctor-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..06733cb0939f15187bb0d34fafcfc9a56a857730
--- /dev/null
+++ b/test/built-ins/Array/from/iter-cstm-ctor-err.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: >
+ Error creating object with custom constructor (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ a. If IsConstructor(C) is true, then
+ i. Let A be Construct(C).
+ b. Else,
+ i. Let A be ArrayCreate(0).
+ c. ReturnIfAbrupt(A).
+features: [Symbol.iterator]
+---*/
+
+var C = function() {
+ throw new Test262Error();
+};
+var items = {};
+items[Symbol.iterator] = function() {};
+
+assert.throws(Test262Error, function() {
+ Array.from.call(C, items);
+});
diff --git a/test/built-ins/Array/from/iter-cstm-ctor.js b/test/built-ins/Array/from/iter-cstm-ctor.js
new file mode 100644
index 0000000000000000000000000000000000000000..a19edeb9a3a93deded8dc0cb717191a497363b01
--- /dev/null
+++ b/test/built-ins/Array/from/iter-cstm-ctor.js
@@ -0,0 +1,46 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Creating object with custom constructor (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ a. If IsConstructor(C) is true, then
+ i. Let A be Construct(C).
+ b. Else,
+ i. Let A be ArrayCreate(0).
+ c. ReturnIfAbrupt(A).
+features: [Symbol.iterator]
+---*/
+
+var thisVal, args;
+var callCount = 0;
+var C = function() {
+ thisVal = this;
+ args = arguments;
+ callCount += 1;
+};
+var result;
+var items = {};
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ return { done: true };
+ }
+ };
+};
+
+result = Array.from.call(C, items);
+
+assert(
+ result instanceof C, 'Constructed value is an instance of the constructor'
+);
+assert.sameValue(
+ result.constructor,
+ C,
+ 'Constructed value correctly defines a `constructor` property'
+);
+assert.sameValue(callCount, 1, 'Constructor invoked exactly once');
+assert.sameValue(thisVal, result, 'Constructed value is returned');
+assert.sameValue(args.length, 0, 'Constructor invoked without arguments');
diff --git a/test/built-ins/Array/from/iter-get-iter-err.js b/test/built-ins/Array/from/iter-get-iter-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..edc5b1717e897a60476fc88a15353c3339c9726e
--- /dev/null
+++ b/test/built-ins/Array/from/iter-get-iter-err.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error creating iterator object
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ d. Let iterator be GetIterator(items, usingIterator).
+ e. ReturnIfAbrupt(iterator).
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+items[Symbol.iterator] = function() {
+ throw new Test262Error();
+};
+
+assert.throws(Test262Error, function() {
+ Array.from(items);
+});
diff --git a/test/built-ins/Array/from/iter-get-iter-val-err.js b/test/built-ins/Array/from/iter-get-iter-val-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..976981d52eb204df7ae6b23c13bce2144406f71d
--- /dev/null
+++ b/test/built-ins/Array/from/iter-get-iter-val-err.js
@@ -0,0 +1,34 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error retrieving value of iterator result
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ v. Let nextValue be IteratorValue(next).
+ vi. ReturnIfAbrupt(nextValue).
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+var poisonedValue = {};
+Object.defineProperty(poisonedValue, 'value', {
+ get: function() {
+ throw new Test262Error();
+ }
+});
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ return poisonedValue;
+ }
+ };
+};
+
+assert.throws(Test262Error, function() {
+ Array.from(items);
+});
diff --git a/test/built-ins/Array/from/iter-map-fn-args.js b/test/built-ins/Array/from/iter-map-fn-args.js
new file mode 100644
index 0000000000000000000000000000000000000000..c7f35b8234498cbfe03e7891d020ce66c9349198
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-args.js
@@ -0,0 +1,63 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: >
+ Arguments of mapping function (traversed via iterator)
+info: >
+ [...]
+ 2. If mapfn is undefined, let mapping be false.
+ 3. else
+ a. If IsCallable(mapfn) is false, throw a TypeError exception.
+ b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+ c. Let mapping be true
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+ 2. If mappedValue is an abrupt completion, return
+ IteratorClose(iterator, mappedValue).
+ 3. Let mappedValue be mappedValue.[[value]].
+features: [Symbol.iterator]
+---*/
+
+var args = [];
+var firstResult = { done: false, value: {} };
+var secondResult = { done: false, value: {} };
+var mapFn = function(value, idx) {
+ args.push(arguments);
+};
+var items = {};
+var nextResult = firstResult;
+var nextNextResult = secondResult;
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextResult;
+ nextResult = nextNextResult;
+ nextNextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+Array.from(items, mapFn);
+
+assert.sameValue(args.length, 2, 'Iteration count');
+
+assert.sameValue(args[0].length, 2, 'First iteration: arguments length');
+assert.sameValue(
+ args[0][0], firstResult.value, 'First iteration: first argument'
+);
+assert.sameValue(args[0][1], 0, 'First iteration: second argument');
+
+assert.sameValue(args[1].length, 2, 'Second iteration: arguments length');
+assert.sameValue(
+ args[1][0], secondResult.value, 'Second iteration: first argument'
+);
+assert.sameValue(args[1][1], 1, 'Second iteration: second argument');
diff --git a/test/built-ins/Array/from/iter-map-fn-err.js b/test/built-ins/Array/from/iter-map-fn-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..a96b8f3c94e1ea3916c94cbeac95fe80944f4b31
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-err.js
@@ -0,0 +1,41 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error invoking map function (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+ 2. If mappedValue is an abrupt completion, return
+ IteratorClose(iterator, mappedValue).
+features: [Symbol.iterator]
+---*/
+
+var closeCount = 0;
+var mapFn = function() {
+ throw new Test262Error();
+};
+var items = {};
+items[Symbol.iterator] = function() {
+ return {
+ return: function() {
+ closeCount += 1;
+ },
+ next: function() {
+ return {
+ done: false
+ };
+ }
+ };
+};
+
+assert.throws(Test262Error, function() {
+ Array.from(items, mapFn);
+});
+
+assert.sameValue(closeCount, 1);
diff --git a/test/built-ins/Array/from/iter-map-fn-return.js b/test/built-ins/Array/from/iter-map-fn-return.js
new file mode 100644
index 0000000000000000000000000000000000000000..ca4c8f37837c571dec9e55b44f2429c96ba9dc8a
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-return.js
@@ -0,0 +1,58 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Value returned by mapping function (traversed via iterator)
+info: >
+ [...]
+ 2. If mapfn is undefined, let mapping be false.
+ 3. else
+ a. If IsCallable(mapfn) is false, throw a TypeError exception.
+ b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+ c. Let mapping be true
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+ 2. If mappedValue is an abrupt completion, return
+ IteratorClose(iterator, mappedValue).
+ 3. Let mappedValue be mappedValue.[[value]].
+features: [Symbol.iterator]
+---*/
+
+var thisVals = [];
+var nextResult = { done: false, value: {} };
+var nextNextResult = { done: false, value: {} };
+var firstReturnVal = {};
+var secondReturnVal = {};
+var mapFn = function(value, idx) {
+ var returnVal = nextReturnVal;
+ nextReturnVal = nextNextReturnVal;
+ nextNextReturnVal = null;
+ return returnVal;
+};
+var nextReturnVal = firstReturnVal;
+var nextNextReturnVal = secondReturnVal;
+var items = {};
+var result;
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextResult;
+ nextResult = nextNextResult;
+ nextNextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+result = Array.from(items, mapFn);
+
+assert.sameValue(result.length, 2);
+assert.sameValue(result[0], firstReturnVal);
+assert.sameValue(result[1], secondReturnVal);
diff --git a/test/built-ins/Array/from/iter-map-fn-this-arg.js b/test/built-ins/Array/from/iter-map-fn-this-arg.js
new file mode 100644
index 0000000000000000000000000000000000000000..26becec78bc40832176c60ee7b302afc193abfd7
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-this-arg.js
@@ -0,0 +1,49 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: >
+ `this` value of mapping function with custom `this` argument (traversed via iterator)
+info: >
+ [...]
+ 2. If mapfn is undefined, let mapping be false.
+ 3. else
+ a. If IsCallable(mapfn) is false, throw a TypeError exception.
+ b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+ c. Let mapping be true
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+features: [Symbol.iterator]
+---*/
+
+var thisVals = [];
+var nextResult = { done: false, value: {} };
+var nextNextResult = { done: false, value: {} };
+var mapFn = function() {
+ thisVals.push(this);
+};
+var items = {};
+var thisVal = {};
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextResult;
+ nextResult = nextNextResult;
+ nextNextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+Array.from(items, mapFn, thisVal);
+
+assert.sameValue(thisVals.length, 2);
+assert.sameValue(thisVals[0], thisVal, 'First iteration `this` value');
+assert.sameValue(thisVals[1], thisVal, 'Second iteration `this` value');
diff --git a/test/built-ins/Array/from/iter-map-fn-this-non-strict.js b/test/built-ins/Array/from/iter-map-fn-this-non-strict.js
new file mode 100644
index 0000000000000000000000000000000000000000..c4e18eb029e9e41e278d0aa0140b0889f438a621
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-this-non-strict.js
@@ -0,0 +1,50 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: >
+ `this` value of mapping function in non-strict mode (traversed via iterator)
+info: >
+ [...]
+ 2. If mapfn is undefined, let mapping be false.
+ 3. else
+ a. If IsCallable(mapfn) is false, throw a TypeError exception.
+ b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+ c. Let mapping be true
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+features: [Symbol.iterator]
+flags: [noStrict]
+---*/
+
+var thisVals = [];
+var nextResult = { done: false, value: {} };
+var nextNextResult = { done: false, value: {} };
+var mapFn = function() {
+ thisVals.push(this);
+};
+var items = {};
+var global = function() { return this; }();
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextResult;
+ nextResult = nextNextResult;
+ nextNextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+Array.from(items, mapFn);
+
+assert.sameValue(thisVals.length, 2);
+assert.sameValue(thisVals[0], global, 'First iteration `this` value');
+assert.sameValue(thisVals[1], global, 'Second iteration `this` value');
diff --git a/test/built-ins/Array/from/iter-map-fn-this-strict.js b/test/built-ins/Array/from/iter-map-fn-this-strict.js
new file mode 100644
index 0000000000000000000000000000000000000000..bb17d90d816635d659f29596ce4a33442109c63b
--- /dev/null
+++ b/test/built-ins/Array/from/iter-map-fn-this-strict.js
@@ -0,0 +1,49 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: >
+ `this` value of mapping function in strict mode (traversed via iterator)
+info: >
+ [...]
+ 2. If mapfn is undefined, let mapping be false.
+ 3. else
+ a. If IsCallable(mapfn) is false, throw a TypeError exception.
+ b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+ c. Let mapping be true
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ vii. If mapping is true, then
+ 1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
+features: [Symbol.iterator]
+flags: [onlyStrict]
+---*/
+
+var thisVals = [];
+var nextResult = { done: false, value: {} };
+var nextNextResult = { done: false, value: {} };
+var mapFn = function() {
+ thisVals.push(this);
+};
+var items = {};
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextResult;
+ nextResult = nextNextResult;
+ nextNextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+Array.from(items, mapFn);
+
+assert.sameValue(thisVals.length, 2);
+assert.sameValue(thisVals[0], undefined, 'First iteration `this` value');
+assert.sameValue(thisVals[1], undefined, 'Second iteration `this` value');
diff --git a/test/built-ins/Array/from/iter-set-elem-prop-err.js b/test/built-ins/Array/from/iter-set-elem-prop-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..64945a070dcb8a374ae400c493dc256bfb601f1f
--- /dev/null
+++ b/test/built-ins/Array/from/iter-set-elem-prop-err.js
@@ -0,0 +1,45 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error setting property on result value (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ ix. Let defineStatus be CreateDataPropertyOrThrow(A, Pk,
+ mappedValue).
+ x. If defineStatus is an abrupt completion, return
+ IteratorClose(iterator, defineStatus).
+features: [Symbol.iterator]
+---*/
+
+var C = function() {
+ Object.defineProperty(this, '0', { configurable: false });
+};
+var closeCount = 0;
+var items = {};
+var nextResult = { done: false };
+
+items[Symbol.iterator] = function() {
+ return {
+ return: function() {
+ closeCount += 1;
+ },
+ next: function() {
+ var result = nextResult;
+
+ nextResult = { done: true };
+
+ return result;
+ }
+ };
+};
+
+assert.throws(TypeError, function() {
+ Array.from.call(C, items);
+});
+
+assert.sameValue(closeCount, 1);
diff --git a/test/built-ins/Array/from/iter-set-elem-prop.js b/test/built-ins/Array/from/iter-set-elem-prop.js
new file mode 100644
index 0000000000000000000000000000000000000000..91762fddde4920fd37e7abf5527d75c38ea9ee4e
--- /dev/null
+++ b/test/built-ins/Array/from/iter-set-elem-prop.js
@@ -0,0 +1,41 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Setting property on result value (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ ix. Let defineStatus be CreateDataPropertyOrThrow(A, Pk,
+ mappedValue).
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+var firstIterResult = { done: false, value: {} };
+var secondIterResult = { done: false, value: {} };
+var thirdIterResult = { done: true, value: {} };
+var nextIterResult = firstIterResult;
+var nextNextIterResult = secondIterResult;
+var result;
+
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextIterResult;
+
+ nextIterResult = nextNextIterResult;
+ nextNextIterResult = thirdIterResult;
+
+ return result;
+ }
+ };
+};
+
+result = Array.from(items);
+
+assert.sameValue(result[0], firstIterResult.value);
+assert.sameValue(result[1], secondIterResult.value);
diff --git a/test/built-ins/Array/from/iter-set-length-err.js b/test/built-ins/Array/from/iter-set-length-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..3379ed7ec4342cbfd424b6707779f3c96326732b
--- /dev/null
+++ b/test/built-ins/Array/from/iter-set-length-err.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Error setting length of object (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ iv. If next is false, then
+ 1. Let setStatus be Set(A, "length", k, true).
+ 2. ReturnIfAbrupt(setStatus).
+features: [Symbol.iterator]
+---*/
+
+var C = function() {};
+var items = {};
+Object.defineProperty(C.prototype, 'length', {
+ set: function(_) {
+ throw new Test262Error();
+ }
+});
+items[Symbol.iterator] = function() {
+ return {
+ next: function() { return { done: true }; }
+ };
+};
+
+assert.throws(Test262Error, function() {
+ Array.from.call(C, items);
+});
diff --git a/test/built-ins/Array/from/iter-set-length.js b/test/built-ins/Array/from/iter-set-length.js
new file mode 100644
index 0000000000000000000000000000000000000000..95913df721d2d94149949069dacbbbd97ad1b8b6
--- /dev/null
+++ b/test/built-ins/Array/from/iter-set-length.js
@@ -0,0 +1,40 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 22.1.2.1
+description: Setting length of object (traversed via iterator)
+info: >
+ [...]
+ 6. If usingIterator is not undefined, then
+ [...]
+ g. Repeat
+ [...]
+ iv. If next is false, then
+ 1. Let setStatus be Set(A, "length", k, true).
+ 2. ReturnIfAbrupt(setStatus).
+ 3. Return A.
+features: [Symbol.iterator]
+---*/
+
+var items = {};
+var result, nextIterResult, lastIterResult;
+items[Symbol.iterator] = function() {
+ return {
+ next: function() {
+ var result = nextIterResult;
+ nextIterResult = lastIterResult;
+ return result;
+ }
+ };
+};
+
+nextIterResult = lastIterResult = { done: true };
+result = Array.from(items);
+
+assert.sameValue(result.length, 0);
+
+nextIterResult = { done: false };
+lastIterResult = { done: true };
+result = Array.from(items);
+
+assert.sameValue(result.length, 1);