| // Copyright (C) 2018 Valerie Young. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| |
| /*--- |
| esid: sec-asyncgenerator-prototype-next |
| description: next() requests from iterator processed in order, await |
| info: > |
| AsyncGenerator.prototype.next ( value ) |
| 1. Let generator be the this value. |
| 2. Let completion be NormalCompletion(value). |
| 3. Return ! AsyncGeneratorEnqueue(generator, completion). |
| |
| AsyncGeneratorEnqueue ( generator, completion ) |
| ... |
| 4. Let queue be generator.[[AsyncGeneratorQueue]]. |
| 5. Let request be AsyncGeneratorRequest{[[Completion]]: completion, |
| [[Capability]]: promiseCapability}. |
| 6. Append request to the end of queue. |
| ... |
| |
| AsyncGeneratorResolve ( generator, value, done ) |
| ... |
| 2. Let queue be generator.[[AsyncGeneratorQueue]]. |
| 3. Assert: queue is not an empty List. |
| 4. Remove the first element from queue and let next be the value of that element. |
| ... |
| |
| flags: [async] |
| features: [async-iteration] |
| ---*/ |
| |
| var yieldorder = 0; |
| var resolveLatePromise; |
| |
| function resolveLater() { |
| return new Promise(resolve => { |
| resolveLatePromise = resolve; |
| }); |
| } |
| |
| async function* g() { |
| yield resolveLater(); |
| yield ++yieldorder; |
| } |
| |
| var iter = g(); |
| |
| assert.sameValue(yieldorder, 0); |
| |
| var item1 = iter.next(); |
| var item2 = iter.next(); |
| var item3 = iter.next(); |
| |
| async function awaitnexts() { |
| assert.sameValue((await item3).value, undefined) |
| assert.sameValue(yieldorder, 2, "All next requests have been proccessed.") |
| assert.sameValue((await item2).value, 2) |
| assert.sameValue((await item1).value, 1) |
| } |
| |
| awaitnexts().then($DONE, $DONE); |
| |
| // At this point: |
| // yieldorder == 0 |
| // item1 is an unresolved promise |
| resolveLatePromise(++yieldorder); |