fix(signals): expose WritableStateSource to withFeature callback

modules/signals/spec/with-feature.spec.ts

@@ -117,7 +117,29 @@ describe('withFeature', () => {
     expect(store.createUrl('docs')).toBe('https://www.ngrx.io/docs');
   });
 
-  it('can be cominbed with inputs', () => {
+  it('provides writable state source', () => {
+    const withCallback = (cb: () => void) =>
+      signalStoreFeature(
+        withMethods(() => ({
+          executeCallBack: () => cb(),
+        }))
+      );
+
+    const Store = signalStore(
+      { providedIn: 'root' },
+      withState({ counter: 1 }),
+      withFeature((store) =>
+        withCallback(() => patchState(store, { counter: 2 }))
+      )
+    );
+
+    const store = TestBed.inject(Store);
+    expect(getState(store)).toEqual({ counter: 1 });
+    store.executeCallBack();
+    expect(getState(store)).toEqual({ counter: 2 });
+  });
+
+  it('can be combined with inputs', () => {
     function withLoadEntities<Entity extends { id: number }, Filter>(config: {
       filter: Signal<Filter>;
       loader: (filter: Filter) => Observable<Entity[]>;

modules/signals/src/with-feature.ts

@@ -3,6 +3,7 @@ import {
   SignalStoreFeatureResult,
   StateSignals,
 } from './signal-store-models';
+import { STATE_SOURCE, WritableStateSource } from './state-source';
 import { Prettify } from './ts-helpers';
 
 /**
@@ -33,12 +34,16 @@ export function withFeature<
 >(
   featureFactory: (
     store: Prettify<
-      StateSignals<Input['state']> & Input['props'] & Input['methods']
+      StateSignals<Input['state']> &
+        Input['props'] &
+        Input['methods'] &
+        WritableStateSource<Prettify<Input['state']>>
     >
   ) => SignalStoreFeature<Input, Output>
 ): SignalStoreFeature<Input, Output> {
   return (store) => {
     const storeForFactory = {
+      [STATE_SOURCE]: store[STATE_SOURCE],
       ...store['stateSignals'],
       ...store['props'],
       ...store['methods'],