test/e2e/resources/memory/weakmap.html

<!--
  Copyright 2024 The Chromium Authors
  Use of this source code is governed by a BSD-style license that can be
  found in the LICENSE file.
-->
<h1>Memory Panel (Heap profiler) Test</h1>
<script>
  class WithData {
    constructor() {
      this.data = new Uint8Array(2 ** 15);
    }
  }
  class CustomClass1 extends WithData {}
  class CustomClass1Key {}
  class CustomClass2 extends WithData {}
  class CustomClass2Key {}
  class CustomClass3 extends WithData {}
  class CustomClass3Key {}
  class CustomClass4 extends WithData {}
  class CustomClass4Key {}
  class CustomClass4Retainer {
    constructor(f) {
      this.f = f;
    }
  }

  // The WeakMap is at distance 3, and its table is a distance 4.
  var weakMap = {a: new WeakMap()};

  // Scenario 1: the key is closer to the root than the WeakMap.
  var key1 = new CustomClass1Key();  // Key object at distance 2
  weakMap.a.set(key1, new CustomClass1());

  // Scenario 2: the WeakMap is closer to the root than the key.
  var key2 = {a: {b: {c: new CustomClass2Key()}}};  // Key object at distance 5
  weakMap.a.set(key2.a.b.c, new CustomClass2());

  // Scenario 3: the value is retained by a shorter path than the key or the WeakMap.
  var key3 = {a: {b: new CustomClass3Key()}};  // Key object at distance 4
  var value3 = new CustomClass3();  // Value object at distance 2
  weakMap.a.set(key3.a.b, value3);

  // Scenario 4: the value retains its own key.
  // The value object is at distance 8 from the root.
  var value4 = {a: {b: {c: {d: {e: new CustomClass4Retainer(new CustomClass4())}}}}};
  value4.a.b.c.d.e.f.key = new CustomClass4Key();
  weakMap.a.set(value4.a.b.c.d.e.f.key, value4.a.b.c.d.e.f);
</script>