TrackedMap, TrackedSet, TrackedWeakMap, and TrackedWeakSet delete() returns true for non-existent entries

[megothss]

🐞 Describe the Bug

The delete() method in all four tracked collections (trackedMap, trackedSet, trackedWeakMap, trackedWeakSet) returns true when the key/value does not exist in the collection. Per the ECMAScript specification, delete() must return false if the element was not present.

The bug is an inverted early-return in each implementation:

delete(key: K): boolean {
  if (!this.#vals.has(key)) return true; // should be `return false`
  ...
}

Affected files:

• packages/@glimmer/validator/lib/collections/map.ts
• packages/@glimmer/validator/lib/collections/set.ts
• packages/@glimmer/validator/lib/collections/weak-map.ts
• packages/@glimmer/validator/lib/collections/weak-set.ts

🔬 Minimal Reproduction

import { trackedMap } from '@ember/reactive/collections';

const map = trackedMap();
console.log(map.delete('nonexistent')); // true (should be false)

map.set('key', 'value');
console.log(map.delete('key')); // true (correct)

Same pattern applies to trackedSet, trackedWeakMap, and trackedWeakSet.

😕 Actual Behavior

delete() returns true when the key/value is not in the collection.

🤔 Expected Behavior

delete() returns false when the key/value is not in the collection, per:

• ECMA-262 Map.prototype.delete
• ECMA-262 Set.prototype.delete
• ECMA-262 WeakMap.prototype.delete
• ECMA-262 WeakSet.prototype.delete

🌍 Environment

• Ember: 6.10.1
• Ember-CLI: -
• Node.js/npm: -
• OS: -
• Browser: -

➕ Additional Context

Existing tests for delete() don't assert the return value, which is how this slipped through. Found at commit 02c62b0d7cbec49271949fcf608e66f1ccb5b3a6.