Dramex 8ea7c7c7e4 fix(collection): preserve ReadonlyCollection through tap/each (#11501) ...

* fix(collection): preserve ReadonlyCollection through tap/each

`each` and `tap` return polymorphic `this`, which TypeScript resolves
against the `Omit<Collection, ...>` portion of `ReadonlyCollection`
rather than the full intersection. That let callers reach `set` and
`delete` on the result of a chain started from a `ReadonlyCollection`:

    const ro: ReadonlyCollection<string, number> = new Collection(...);
    ro.tap(() => {}).set('x', 0); // compiled, mutated the underlying Map

The fix omits `each` and `tap` from the base `Omit` and re-declares
them on the `ReadonlyCollection` side of the intersection so the return
type narrows back to `ReadonlyCollection`.

Closes #10514

* test(collection): gate readonly-chain checks behind if(false)

Previously the `@ts-expect-error` lines still executed the `set` and
`delete` mutations at runtime, and the final `size === 1` passed only
because they happened to cancel out. Wrapping the assertions in
`if (false)` keeps the compile-time guarantee while the backing
collection is truly untouched, and adds a `get('a') === 1` check as
a belt.

* test(collection): move readonly type checks to *.test-d.ts

Addresses review feedback. The type-level assertions around tap() and
each() preserving ReadonlyCollection belong in a *.test-d.ts file so
they run through vitest's typecheck pass instead of runtime.

Replaces the if(false)-gated @ts-expect-error block in collection.test.ts
with expectTypeOf assertions in a new collection.test-d.ts. Covers both
the no-thisArg and with-thisArg overloads of tap and each.

2026-04-20 19:15:29 +00:00

..

collection.test-d.ts

fix(collection): preserve ReadonlyCollection through tap/each (#11501)

2026-04-20 19:15:29 +00:00

collection.test.ts

perf: Optimize Collection.equals() to reduce redundant map lookups (#11344)

2025-12-09 21:22:14 +00:00