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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --harmony-await-optimization
// test basic interleaving
(function () {
const actual = [];
const expected = [ 'await', 1, 'await', 2 ];
const iterations = 2;
async function pushAwait() {
actual.push('await');
}
async function callAsync() {
for (let i = 0; i < iterations; i++) {
await pushAwait();
}
return 0;
}
function checkAssertions() {
assertArrayEquals(expected, actual,
'Async/await and promises should be interleaved.');
}
assertPromiseResult((async() => {
callAsync();
return new Promise(function (resolve) {
actual.push(1);
resolve();
}).then(function () {
actual.push(2);
}).then(checkAssertions);
})());
})();
// test async generators
(function () {
const actual = [];
const expected = [ 'await', 1, 'await', 2 ];
const iterations = 2;
async function pushAwait() {
actual.push('await');
}
async function* callAsync() {
for (let i = 0; i < iterations; i++) {
await pushAwait();
}
return 0;
}
function checkAssertions() {
assertArrayEquals(expected, actual,
'Async/await and promises should be interleaved when using async generators.');
}
assertPromiseResult((async() => {
callAsync().next();
return new Promise(function (resolve) {
actual.push(1);
resolve();
}).then(function () {
actual.push(2);
}).then(checkAssertions);
})());
})();
// test yielding from async generators
(function () {
const actual = [];
const expected = [
'Promise: 6',
'Promise: 5',
'Await: 3',
'Promise: 4',
'Promise: 3',
'Await: 2',
'Promise: 2',
'Promise: 1',
'Await: 1',
'Promise: 0'
];
const iterations = 3;
async function* naturalNumbers(start) {
let current = start;
while (current > 0) {
yield Promise.resolve(current--);
}
}
async function trigger() {
for await (const num of naturalNumbers(iterations)) {
actual.push('Await: ' + num);
}
}
async function checkAssertions() {
assertArrayEquals(expected, actual,
'Async/await and promises should be interleaved when yielding.');
}
async function countdown(counter) {
actual.push('Promise: ' + counter);
if (counter > 0) {
return Promise.resolve(counter - 1).then(countdown);
} else {
await checkAssertions();
}
}
assertPromiseResult((async() => {
trigger();
return countdown(iterations * 2);
})());
})();
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