89 lines
2.4 KiB
JavaScript
89 lines
2.4 KiB
JavaScript
var failIfThrows = function (done) {
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'use strict';
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return function (e) {
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done(e || new Error());
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};
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};
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var delayPromise = function (value, ms) {
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'use strict';
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return new Promise(function (resolve) {
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setTimeout(function () {
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resolve(value);
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}, ms);
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});
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};
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describe('Promise.race', function () {
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'use strict';
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it('should not be enumerable', function () {
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expect(Promise).ownPropertyDescriptor('race').to.have.property('enumerable', false);
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});
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it('should fulfill if all promises are settled and the ordinally-first is fulfilled', function (done) {
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var iterable = [Promise.resolve(1), Promise.reject(2), Promise.resolve(3)];
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Promise.race(iterable).then(function (value) {
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assert.strictEqual(value, 1);
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}).then(done, failIfThrows(done));
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});
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it('should reject if all promises are settled and the ordinally-first is rejected', function (done) {
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var iterable = [Promise.reject(1), Promise.reject(2), Promise.resolve(3)];
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Promise.race(iterable).then(
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function () {
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assert(false, 'should never get here');
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},
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function (reason) {
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assert.strictEqual(reason, 1);
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}
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).then(done, failIfThrows(done));
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});
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it('should settle in the same way as the first promise to settle', function (done) {
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// ensure that even if timeouts are delayed an all execute together,
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// p2 will settle first.
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var p2 = delayPromise(2, 200);
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var p1 = delayPromise(1, 1000);
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var p3 = delayPromise(3, 500);
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var iterable = [p1, p2, p3];
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Promise.race(iterable).then(function (value) {
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assert.strictEqual(value, 2);
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}).then(done, failIfThrows(done));
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});
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// see https://github.com/domenic/promises-unwrapping/issues/75
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it('should never settle when given an empty iterable', function (done) {
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var iterable = [];
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var settled = false;
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Promise.race(iterable).then(
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function () { settled = true; },
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function () { settled = true; }
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);
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setTimeout(function () {
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assert.strictEqual(settled, false);
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done();
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}, 300);
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});
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it('should reject with a TypeError if given a non-iterable', function (done) {
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var notIterable = {};
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Promise.race(notIterable).then(
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function () {
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assert(false, 'should never get here');
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},
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function (reason) {
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assert(reason instanceof TypeError);
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}
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).then(done, failIfThrows(done));
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});
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});
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