Function patchState

modules/signals/src/state-source.ts:79–115

(
  stateSource: WritableStateSource<State>,
  ...updaters: Array<
    Partial<NoInfer<State>> | PartialStateUpdater<NoInfer<State>>
  >
)

 * ```
 */
export function patchState<State extends object>(
  stateSource: WritableStateSource<State>,
  ...updaters: Array<
    Partial<NoInfer<State>> | PartialStateUpdater<NoInfer<State>>
  >
): void {
  const currentState = untracked(() => getState(stateSource));
  const newState = updaters.reduce(
    (nextState: State, updater) => ({
      ...nextState,
      ...(typeof updater === 'function' ? updater(nextState) : updater),
    }),
    currentState
  );

  const signals = stateSource[STATE_SOURCE];
  const stateKeys = Reflect.ownKeys(stateSource[STATE_SOURCE]);

  for (const key of Reflect.ownKeys(newState)) {
    if (stateKeys.includes(key)) {
      const signalKey = key as keyof State;
      if (currentState[signalKey] !== newState[signalKey]) {
        signals[signalKey].set(newState[signalKey]);
      }
    } else if (typeof ngDevMode !== 'undefined' && ngDevMode) {
      console.warn(
        `@ngrx/signals: patchState was called with an unknown state slice '${String(
          key
        )}'.`,
        'Ensure that all state properties are explicitly defined in the initial state.',
        'Updates to properties not present in the initial state will be ignored.'
      );
    }
  }

  notifyWatchers(stateSource);
}

/**
 * @description