tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

invoke-resolve-get-once-no-calls.js (1029B)


      1 // Copyright (C) 2019 Leo Balter. All rights reserved.
      2 // This code is governed by the BSD license found in the LICENSE file.
      3 
      4 /*---
      5 description: >
      6  Gets constructor's `resolve` method once from zero to many invocations.
      7 esid: sec-promise.all
      8 info: |
      9  Runtime Semantics: PerformPromiseAll
     10 
     11  1. Let promiseResolve be ? Get(constructor, `"resolve"`).
     12  1. If IsCallable(promiseResolve) is false, throw a TypeError exception.
     13  ...
     14  1. Repeat,
     15    ...
     16    1. Let nextPromise be ? Call(promiseResolve, constructor, « nextValue »).
     17 ---*/
     18 
     19 var resolve = Promise.resolve;
     20 var getCount = 0;
     21 var callCount = 0;
     22 
     23 Object.defineProperty(Promise, 'resolve', {
     24  configurable: true,
     25  get() {
     26    getCount += 1;
     27    return function() {
     28      callCount += 1;
     29      return resolve.apply(Promise, arguments);
     30    };
     31  }
     32 });
     33 
     34 Promise.all([]);
     35 
     36 assert.sameValue(
     37  getCount, 1, 'Got `resolve` only once for each iterated value'
     38 );
     39 assert.sameValue(
     40  callCount, 0, '`resolve` not called for empty iterator'
     41 );
     42 
     43 reportCompare(0, 0);