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Implement Iterator.prototype.flatMap method
Signed-off-by: 2jaeheon <[email protected]>
1 parent 6d0874b commit 6242f09

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‎src/builtins/BuiltinIterator.cpp

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Original file line numberDiff line numberDiff line change
@@ -132,6 +132,17 @@ struct IteratorData : public gc {
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{
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}
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};
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struct FlatMapIteratorData : public IteratorData {
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IteratorRecord* innerIterator;
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bool innerAlive;
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FlatMapIteratorData(Value mapper)
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: IteratorData(mapper)
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, innerIterator(nullptr)
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, innerAlive(false)
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{
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}
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};
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static std::pair<Value, bool> iteratorMapClosure(ExecutionState& state, IteratorHelperObject* obj, void* data)
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{
@@ -739,6 +750,117 @@ static Value builtinIteratorToArray(ExecutionState& state, Value thisValue, size
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}
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}
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static std::pair<Value, bool> iteratorFlatMapClosure(ExecutionState& state, IteratorHelperObject* obj, void* data)
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{
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// Let closure be a new Abstract Closure with no parameters that captures iterated and mapper and performs the following steps when called:
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// a. Let counter be 0.
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// b. Repeat,
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// i. Let value be ? IteratorStepValue(iterated).
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// ii. If value is done, return ReturnCompletion(undefined).
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// iii. Let mapped be Completion(Call(mapper, undefined, « value, 𝔽(counter) »)).
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// iv. IfAbruptCloseIterator(mapped, iterated).
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// v. Let innerIterator be Completion(GetIteratorFlattenable(mapped, reject-primitives)).
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// vi. IfAbruptCloseIterator(innerIterator, iterated).
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// vii. Let innerAlive be true.
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// viii. Repeat, while innerAlive is true,
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// 1. Let innerValue be Completion(IteratorStepValue(innerIterator)).
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// 2. IfAbruptCloseIterator(innerValue, iterated).
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// 3. If innerValue is done, then
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// a. Set innerAlive to false.
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// 4. Else,
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// a. Let completion be Completion(Yield(innerValue)).
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// b. If completion is an abrupt completion, then
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// i. Let backupCompletion be Completion(IteratorClose(innerIterator, completion)).
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// ii. IfAbruptCloseIterator(backupCompletion, iterated).
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// iii. Return ? IteratorClose(iterated, completion).
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// ix. Set counter to counter + 1.
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IteratorRecord* iterated = obj->underlyingIterator();
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FlatMapIteratorData* closureData = reinterpret_cast<FlatMapIteratorData*>(data);
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Value mapper = closureData->callback;
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while (true) {
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// while innerAlive is true, Let innerValue be Completion(IteratorStepValue(innerIterator)).
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if (closureData->innerAlive && closureData->innerIterator) {
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Optional<Value> innerValue;
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try {
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innerValue = IteratorObject::iteratorStepValue(state, closureData->innerIterator);
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} catch (const Value& e) {
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// IfAbruptCloseIterator(innerValue, iterated).
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IteratorObject::iteratorClose(state, obj->underlyingIterator(), e, true);
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}
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if (!innerValue) {
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// If innerValue is done, then Set innerAlive to false.
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closureData->innerAlive = false;
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closureData->innerIterator = nullptr;
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} else {
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// Else, Let completion be Completion(Yield(innerValue)).
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return std::make_pair(innerValue.value(), false);
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}
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}
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// Let value be ? IteratorStepValue(iterated).
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auto value = IteratorObject::iteratorStepValue(state, iterated);
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// If value is done, return ReturnCompletion(undefined).
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if (!value) {
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iterated->m_done = true;
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return std::make_pair(Value(), true);
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}
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// Let mapped be Completion(Call(mapper, undefined, « value, 𝔽(counter) »)).
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Value args[2] = { value.value(), Value(closureData->counter) };
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Value mapped;
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try {
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mapped = Object::call(state, mapper, Value(), 2, args);
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} catch (const Value& e) {
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// IfAbruptCloseIterator(mapped, iterated).
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IteratorObject::iteratorClose(state, iterated, e, true);
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}
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// Let innerIterator be Completion(GetIteratorFlattenable(mapped, reject-primitives)).
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IteratorRecord* innerIterator = nullptr;
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try {
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innerIterator = IteratorObject::getIteratorFlattenable(state, mapped, IteratorObject::PrimitiveHandling::RejectPrimitives);
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} catch (const Value& e) {
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IteratorObject::iteratorClose(state, iterated, e, true);
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}
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// Let innerAlive be true.
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// Set counter to counter + 1.
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closureData->innerAlive = true;
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closureData->innerIterator = innerIterator;
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closureData->counter = StorePositiveNumberAsOddNumber(closureData->counter + 1);
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}
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}
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static Value builtinIteratorFlatMap(ExecutionState& state, Value thisValue, size_t argc, Value* argv, Optional<Object*> newTarget)
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{
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// Let O be the this value.
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const Value& O = thisValue;
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// If O is not an Object, throw a TypeError exception.
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if (!O.isObject()) {
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ErrorObject::throwBuiltinError(state, ErrorCode::TypeError, "this value is not Object");
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}
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// If IsCallable(mapper) is false, throw a TypeError exception.
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const Value& mapper = argv[0];
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if (!mapper.isCallable()) {
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ErrorObject::throwBuiltinError(state, ErrorCode::TypeError, "mapper is not callable");
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}
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// Set iterated to ? GetIteratorDirect(O).
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IteratorRecord* iterated = IteratorObject::getIteratorDirect(state, O.asObject());
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// Let result be CreateIteratorFromClosure(closure, "Iterator Helper", %IteratorHelperPrototype%, « [[UnderlyingIterator]] »).
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// Set result.[[UnderlyingIterator]] to iterated.
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IteratorHelperObject* result = new IteratorHelperObject(state, iteratorFlatMapClosure, iterated, new FlatMapIteratorData(mapper));
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// Return result.
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return result;
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}
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static Value builtinGenericIteratorNext(ExecutionState& state, Value thisValue, size_t argc, Value* argv, Optional<Object*> newTarget)
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{
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if (!thisValue.isObject() || !thisValue.asObject()->isGenericIteratorObject()) {
@@ -840,6 +962,9 @@ void GlobalObject::installIterator(ExecutionState& state)
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m_iteratorPrototype->directDefineOwnProperty(state, ObjectPropertyName(strings->toArray),
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ObjectPropertyDescriptor(new NativeFunctionObject(state, NativeFunctionInfo(strings->toArray, builtinIteratorToArray, 0, NativeFunctionInfo::Strict)), (ObjectPropertyDescriptor::PresentAttribute)(ObjectPropertyDescriptor::WritablePresent | ObjectPropertyDescriptor::ConfigurablePresent)));
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m_iteratorPrototype->directDefineOwnProperty(state, ObjectPropertyName(strings->flatMap),
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ObjectPropertyDescriptor(new NativeFunctionObject(state, NativeFunctionInfo(strings->flatMap, builtinIteratorFlatMap, 1, NativeFunctionInfo::Strict)), (ObjectPropertyDescriptor::PresentAttribute)(ObjectPropertyDescriptor::WritablePresent | ObjectPropertyDescriptor::ConfigurablePresent)));
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843968
directDefineOwnProperty(state, ObjectPropertyName(strings->Iterator),
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ObjectPropertyDescriptor(m_iterator, (ObjectPropertyDescriptor::PresentAttribute)(ObjectPropertyDescriptor::WritablePresent | ObjectPropertyDescriptor::ConfigurablePresent)));
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}

‎tools/test/test262/excludelist.orig.xml

Lines changed: 0 additions & 38 deletions
Original file line numberDiff line numberDiff line change
@@ -254,45 +254,7 @@
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<test id="built-ins/Iterator/prototype/filter/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/find/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/callable"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/exhaustion-does-not-call-return"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/flattens-iterable"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/flattens-iterator"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/flattens-only-depth-1"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/get-next-method-only-once"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/get-next-method-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/get-return-method-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/is-function"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/iterable-primitives-are-not-flattened"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/iterable-to-iterator-fallback"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/iterator-already-exhausted"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/iterator-return-method-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/length"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-args"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-returns-closed-iterator"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-returns-non-object"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-this"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/mapper-throws-then-closing-iterator-also-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/name"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/next-method-returns-non-object"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/next-method-returns-throwing-done"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/next-method-returns-throwing-value"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/next-method-returns-throwing-value-done"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/next-method-throws"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/prop-desc"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/proto"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/result-is-iterator"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/return-is-forwarded-to-mapper-result"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/return-is-forwarded-to-underlying-iterator"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/return-is-not-forwarded-after-exhaustion"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/strings-are-not-flattened"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/this-non-callable-next"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/this-plain-iterator"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/throws-typeerror-when-generator-is-running"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/underlying-iterator-advanced-in-parallel"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/underlying-iterator-closed"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/flatMap/underlying-iterator-closed-in-parallel"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/forEach/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/map/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>
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<test id="built-ins/Iterator/prototype/reduce/argument-validation-failure-closes-underlying"><reason>TODO</reason></test>

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