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// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-generator-function-definitions-runtime-semantics-evaluation
es6id: 14.4.14
description: >
`value` property is not accessed when iteration is incomplete
info: |
YieldExpression : yield * AssignmentExpression
1. Let exprRef be the result of evaluating AssignmentExpression.
2. Let value be ? GetValue(exprRef).
3. Let iterator be ? GetIterator(value).
4. Let received be NormalCompletion(undefined).
5. Repeat
a. If received.[[Type]] is normal, then
[...]
b. Else if received.[[Type]] is throw, then
[...]
c. Else,
i. Assert: received.[[Type]] is return.
ii. Let return be ? GetMethod(iterator, "return").
iii. If return is undefined, return Completion(received).
iv. Let innerReturnResult be ? Call(return, iterator, «
received.[[Value]] »).
v. If Type(innerReturnResult) is not Object, throw a TypeError
exception.
vi. Let done be ? IteratorComplete(innerReturnResult).
vii. If done is true, then
1. Let value be ? IteratorValue(innerReturnResult).
2. Return Completion{[[Type]]: return, [[Value]]: value,
[[Target]]: empty}.
viii. Let received be GeneratorYield(innerReturnResult).
7.4.3 IteratorComplete
1. Assert: Type(iterResult) is Object.
2. Return ToBoolean(? Get(iterResult, "done")).
features: [generators, Symbol.iterator]
---*/
var badIter = {};
var callCount = 0;
var spyValue = Object.defineProperty({ done: false }, 'value', {
get: function() {
callCount += 1;
}
});
badIter[Symbol.iterator] = function() {
return {
next: function() {
return { done: false };
},
return: function() {
return spyValue;
}
};
};
var normalCompletion = false;
var errorCompletion = false;
var delegationComplete = false;
function* g() {
try {
yield * badIter;
normalCompletion = true;
} catch (_) {
errorCompletion = true;
} finally {
delegationComplete = true;
}
}
var iter = g();
iter.next();
assert.sameValue(callCount, 0, 'access count (first iteration)');
assert.sameValue(
delegationComplete, false, 'delegation ongoing (first iteration)'
);
iter.return();
assert.sameValue(callCount, 0, 'access count (second iteration)');
assert.sameValue(
delegationComplete, false, 'delegation ongoing (second iteration)'
);
spyValue.done = true;
iter.return();
assert.sameValue(callCount, 1, 'access count (final iteration)');
assert.sameValue(delegationComplete, true, 'delegation complete');
assert.sameValue(normalCompletion, false, 'completion was abrupt');
assert.sameValue(errorCompletion, false, 'completion was not of type "throw"');
reportCompare(0, 0);