invoke-then.js - mozsearch

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// Copyright (C) 2015 the V8 project authors. All rights reserved.

// This code is governed by the BSD license found in the LICENSE file.

/*---

description: >

    Invocation of the instance's `then` method

es6id: 25.4.4.1

info: |

    11. Let result be PerformPromiseAll(iteratorRecord, C, promiseCapability).

    [...]

    25.4.4.1.1 Runtime Semantics: PerformPromiseAll

    [...]

    6. Repeat

        [...]

        r. Let result be Invoke(nextPromise, "then", «resolveElement,

           resultCapability.[[Reject]]»).

---*/

var p1 = new Promise(function() {});

var p2 = new Promise(function() {});

var p3 = new Promise(function() {});

var callCount = 0;

var currentThis = p1;

var nextThis = p2;

var afterNextThis = p3;

p1.then = p2.then = p3.then = function(a, b) {

  assert.sameValue(typeof a, 'function', 'type of first argument');

  assert.sameValue(

    a.length,

1,

    'ES6 25.4.1.3.2: The length property of a promise resolve function is 1.'

);

  assert.sameValue(typeof b, 'function', 'type of second argument');

  assert.sameValue(

    b.length,

1,

    'ES6 25.4.1.3.1: The length property of a promise reject function is 1.'

);

  assert.sameValue(arguments.length, 2, '`then` invoked with two arguments');

  assert.sameValue(this, currentThis, '`this` value');

  currentThis = nextThis;

  nextThis = afterNextThis;

  afterNextThis = null;

  callCount += 1;

};

Promise.all([p1, p2, p3]);

assert.sameValue(callCount, 3, '`then` invoked once for every iterated value');

reportCompare(0, 0);