feat(collection): honour subclassing via @@species in static methods (#10723)

* feat(collection): use @@species in static methods

* test(collection): subclassing tests

* chore: trigger ci

---------

Co-authored-by: almeidx <github@almeidx.dev>
This commit is contained in:
René
2025-01-26 13:14:48 +00:00
committed by GitHub
parent 0ab6abbcff
commit b7e0fe3689
2 changed files with 63 additions and 3 deletions

View File

@@ -1099,3 +1099,58 @@ describe('findLastKey() tests', () => {
}, null);
});
});
describe('subclassing tests', () => {
class DerivedCollection<Key, Value> extends Collection<Key, Value> {}
test('constructor[Symbol.species]', () => {
expect(DerivedCollection[Symbol.species]).toStrictEqual(DerivedCollection);
});
describe('methods that construct new collections return subclassed objects', () => {
const coll = new DerivedCollection();
test('filter()', () => {
expect(coll.filter(Boolean)).toBeInstanceOf(DerivedCollection);
});
test('partition()', () => {
for (const partition of coll.partition(Boolean)) {
expect(partition).toBeInstanceOf(DerivedCollection);
}
});
test('flatMap()', () => {
expect(coll.flatMap(() => new Collection())).toBeInstanceOf(DerivedCollection);
});
test('mapValues()', () => {
expect(coll.mapValues(Object)).toBeInstanceOf(DerivedCollection);
});
test('clone()', () => {
expect(coll.clone()).toBeInstanceOf(DerivedCollection);
});
test('intersection()', () => {
expect(coll.intersection(new Collection())).toBeInstanceOf(DerivedCollection);
});
test('union()', () => {
expect(coll.union(new Collection())).toBeInstanceOf(DerivedCollection);
});
test('difference()', () => {
expect(coll.difference(new Collection())).toBeInstanceOf(DerivedCollection);
});
test('symmetricDifference()', () => {
expect(coll.symmetricDifference(new Collection())).toBeInstanceOf(DerivedCollection);
});
test('merge()', () => {
const fn = () => ({ keep: false }) as const; // eslint-disable-line unicorn/consistent-function-scoping
expect(coll.merge(new Collection(), fn, fn, fn)).toBeInstanceOf(DerivedCollection);
});
test('toReversed()', () => {
expect(coll.toReversed()).toBeInstanceOf(DerivedCollection);
});
test('toSorted()', () => {
expect(coll.toSorted()).toBeInstanceOf(DerivedCollection);
});
test('Collection.combineEntries()', () => {
expect(DerivedCollection.combineEntries([], Object)).toBeInstanceOf(DerivedCollection);
});
});
});

View File

@@ -11,11 +11,11 @@ export type ReadonlyCollection<Key, Value> = Omit<
export interface Collection<Key, Value> {
/**
* Ambient declaration to allow `this.constructor[@@species]` in class methods.
* Ambient declaration to allow references to `this.constructor` in class methods.
*
* @internal
*/
constructor: typeof Collection & { readonly [Symbol.species]: typeof Collection };
constructor: typeof Collection;
}
/**
@@ -1076,7 +1076,7 @@ export class Collection<Key, Value> extends Map<Key, Value> {
entries: Iterable<[Key, Value]>,
combine: (firstValue: Value, secondValue: Value, key: Key) => Value,
): Collection<Key, Value> {
const coll = new Collection<Key, Value>();
const coll = new this[Symbol.species]<Key, Value>();
for (const [key, value] of entries) {
if (coll.has(key)) {
coll.set(key, combine(coll.get(key)!, value, key));
@@ -1087,6 +1087,11 @@ export class Collection<Key, Value> extends Map<Key, Value> {
return coll;
}
/**
* @internal
*/
declare public static readonly [Symbol.species]: typeof Collection;
}
/**