`@ngrx/signals`: `patchState` blocks when State signal throws an error

[rainerhahnekamp]

Which @ngrx/* package(s) are the source of the bug?

signals

Minimal reproduction of the bug/regression with instructions

Signals can throw an error when they are accessed. This can happen for state
slices that are backed by APIs like resource or linkedSignal.

patchState currently calls getState internally before applying an update, so
it eagerly reads every state slice. As a result, patching an unrelated state
slice can lead to a dead-end, in that sense that other state slices are not
patchable anymore.

Reproduction

const Store = signalStore(
  { providedIn: 'root', protectedState: false },
  withState({ name: '' }),
  withLinkedState(() => {
    const { value } = resource({
      loader: async () => {
        throw new Error('Failed to load value.');
      },
    });

    return { value };
  })
);

const store = inject(Store);

patchState(store, { name: 'John' });

Expected behavior

It should not block

Versions of NgRx, Angular, Node, affected browser(s) and operating system(s)

NgRx 21

Other information

No response

I would be willing to submit a PR to fix this issue

• Yes
• No