test262/test/built-ins/Promise/race/resolve-poisoned-then.js
Mike Pennisi 23d566209a Make asynchronous test configuration explicit
For asynchronous tests, the contract between test file and test runner
is implicit: runners are expected to inspect the source code for
references to a global `$DONE` identifier.

Promote a more explicit contract between test file and test runner by
introducing a new frontmatter "tag", `async`. This brings asynchronous
test configuration in-line with other configuration mechanisms and also
provides a more natural means of test filtering.

The modifications to test files was made programatically using the
`grep` and `sed` utilities:

    $ grep "\$DONE" test/ -r --files-with-match --null | \
        xargs -0 sed -i 's/^\(flags:\s*\)\[/\1[async, /g'
    $ grep "\$DONE" test/ -rl --null | \
        xargs -0 grep -E '^flags:' --files-without-match --null | \
        xargs -0 sed -i 's/^---\*\//flags: [async]\n---*\//'
2016-02-12 13:03:19 -05:00

48 lines
1.2 KiB
JavaScript

// This code is governed by the BSD license found in the LICENSE file.
/*---
description: Resolving with an object with a "poisoned" `then` property
es6id: 25.4.4.3
info: >
[...]
6. Let promiseCapability be NewPromiseCapability(C).
[...]
11. Let result be PerformPromiseRace(iteratorRecord, promiseCapability, C).
[...]
25.4.4.3.1 Runtime Semantics: PerformPromiseRace
1. Repeat
[...]
j. Let result be Invoke(nextPromise, "then",
«promiseCapability.[[Resolve]], promiseCapability.[[Reject]]»).
25.4.1.3.2 Promise Resolve Functions
[...]
8. Let then be Get(resolution, "then").
9. If then is an abrupt completion, then
a. Return RejectPromise(promise, then.[[value]]).
flags: [async]
---*/
var value = {};
var poisonedThen = Object.defineProperty({}, 'then', {
get: function() {
throw value;
}
});
var thenable = {
then: function(resolve) {
resolve(poisonedThen);
}
};
Promise.race([thenable])
.then(function() {
$DONE('The promise should not be fulfilled.');
}, function(val) {
if (val !== value) {
$DONE('The promise should be rejected with the correct value.');
return;
}
$DONE();
});