test262/test/language/expressions/yield/star-rhs-iter-rtrn-no-rtrn.js

77 lines
1.9 KiB
JavaScript

// 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: >
"Return" completion returned when `return` method is not defined
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).
features: [generators, Symbol.iterator]
---*/
var badIter = {};
var throwCount = 0;
var returnCount = 0;
var hitNextStatement = false;
var hitCatch = false;
var hitFinally = false;
var spyResult = {
next: function() {
return { done: false };
}
};
Object.defineProperty(spyResult, 'throw', {
get: function() {
throwCount += 1;
}
});
Object.defineProperty(spyResult, 'return', {
get: function() {
returnCount += 1;
}
});
badIter[Symbol.iterator] = function() {
return spyResult;
};
function* g() {
try {
yield * badIter;
hitNextStatement = true;
} catch (_) {
hitCatch = true;
} finally {
hitFinally = true;
}
}
var iter = g();
iter.next();
iter.return();
assert.sameValue(throwCount, 0, '`throw` property access');
assert.sameValue(returnCount, 1, '`return` property access');
assert.sameValue(
hitFinally, true, 'Generator execution was resumed'
);
assert.sameValue(
hitNextStatement, false, 'Abrupt completion interrupted control flow'
);
assert.sameValue(
hitCatch, false, 'Abrupt completion not interpreted as "throw"'
);