resultEqualityCheck gets a WeakRef instead of derefed previous value.

[uncaught]

I don't know the exact circumstances, but I'm getting errors because resultEqualityCheck gets a WeakRef instead of the expected Set:

Looks like the WeakRef is "cleared":

So this line would still keep the WeakRef in lastResultValue:

const lastResultValue = lastResult?.deref?.() ?? lastResult

Should better be:

const lastResultValue = lastResult?.deref ? lastResult.deref() : lastResult

[uncaught]

Looks like this was fixed already over a year ago: cea19b9

Could you please create a new release!

Also I've tried to add a test, but I can't get the garbage collection to run. Maybe you have more luck:

  test.skipIf(!global.gc)('resultEqualityCheck is not called with a WeakRef', async () => {
    type Source = { foo: string };
    type Result = Set<string>;

    const fn = (value: Source): Result => new Set([value.foo])
    const resultEqualityCheck = vi.fn(() => true)
    const memoized = weakMapMemoize(fn, { resultEqualityCheck })

    let resolve: (v: void) => void
    const promise = new Promise<void>(r => (resolve = r))

    const registry = new FinalizationRegistry(() => {
      resolve()
    })

    for (let i = 0; i < 100; i++) {
      const result = memoized({ foo: 'bar' })
      registry.register(result, i)
      resultEqualityCheck.mockClear()
    }

    global.gc()

    await promise

    memoized({ foo: 'bar' })
    expect(resultEqualityCheck).toHaveBeenCalledWith(new Set(['bar']), new Set(['bar']))
  })