tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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this-constructor-operations.js (2305B)

      1 // |reftest| async
      2 // Copyright (C) 2023 Igalia, S.L. All rights reserved.
      3 // This code is governed by the BSD license found in the LICENSE file.
      4 
      5 /*---
      6 esid: sec-array.fromasync
      7 description: >
      8  Order of user-observable operations on a custom this-value and its instances
      9 includes: [compareArray.js, asyncHelpers.js]
     10 flags: [async]
     11 features: [Array.fromAsync]
     12 ---*/
     13 
     14 function formatPropertyName(propertyKey, objectName = "") {
     15  switch (typeof propertyKey) {
     16    case "symbol":
     17      if (Symbol.keyFor(propertyKey) !== undefined) {
     18        return `${objectName}[Symbol.for('${Symbol.keyFor(propertyKey)}')]`;
     19      } else if (propertyKey.description.startsWith('Symbol.')) {
     20        return `${objectName}[${propertyKey.description}]`;
     21      } else {
     22        return `${objectName}[Symbol('${propertyKey.description}')]`
     23      }
     24    case "string":
     25      if (propertyKey !== String(Number(propertyKey)))
     26        return objectName ? `${objectName}.${propertyKey}` : propertyKey;
     27      // fall through
     28    default:
     29      // integer or string integer-index
     30      return `${objectName}[${propertyKey}]`;
     31  }
     32 }
     33 
     34 asyncTest(async function () {
     35  const expectedCalls = [
     36    "construct MyArray",
     37    "defineProperty A[0]",
     38    "defineProperty A[1]",
     39    "set A.length"
     40  ];
     41  const actualCalls = [];
     42 
     43  function MyArray(...args) {
     44    actualCalls.push("construct MyArray");
     45    return new Proxy(Object.create(null), {
     46      set(target, key, value) {
     47        actualCalls.push(`set ${formatPropertyName(key, "A")}`);
     48        return Reflect.set(target, key, value);
     49      },
     50      defineProperty(target, key, descriptor) {
     51        actualCalls.push(`defineProperty ${formatPropertyName(key, "A")}`);
     52        return Reflect.defineProperty(target, key, descriptor);
     53      }
     54    });
     55  }
     56 
     57  let result = await Array.fromAsync.call(MyArray, [1, 2]);
     58  assert.compareArray(expectedCalls, actualCalls, "order of operations for array argument");
     59 
     60  actualCalls.splice(0);  // reset
     61 
     62  const expectedCallsForArrayLike = [
     63    "construct MyArray",
     64    "defineProperty A[0]",
     65    "defineProperty A[1]",
     66    "set A.length"
     67  ];
     68  result = await Array.fromAsync.call(MyArray, {
     69    length: 2,
     70    0: 1,
     71    1: 2
     72  });
     73  assert.compareArray(expectedCallsForArrayLike, actualCalls, "order of operations for array-like argument");
     74 });