feat(signals): add signalStore and signalStoreFeature (#4049)

Closes #4000

modules/signals/spec/helpers.ts

@@ -1,4 +1,4 @@
-import { Component } from '@angular/core';
+import { Component, inject, Type } from '@angular/core';
 import { TestBed } from '@angular/core/testing';
 
 export function testEffects(testFn: (tick: () => void) => void): () => void {
@@ -13,3 +13,28 @@ export function testEffects(testFn: (tick: () => void) => void): () => void {
     TestBed.runInInjectionContext(() => testFn(() => fixture.detectChanges()));
   };
 }
+
+export function createLocalStore<Store extends Type<unknown>>(
+  storeToken: Store
+): {
+  store: InstanceType<Store>;
+  destroy: () => void;
+} {
+  @Component({
+    standalone: true,
+    template: '',
+    providers: [storeToken],
+  })
+  class TestComponent {
+    store = inject(storeToken);
+  }
+
+  const fixture = TestBed.configureTestingModule({
+    imports: [TestComponent],
+  }).createComponent(TestComponent);
+
+  return {
+    store: fixture.componentInstance.store,
+    destroy: () => fixture.destroy(),
+  };
+}

modules/signals/spec/patch-state.spec.ts

@@ -1,4 +1,5 @@
-import { patchState, signalState } from '../src';
+import { patchState, signalState, signalStore, withState } from '../src';
+import { STATE_SIGNAL } from '../src/signal-state';
 
 describe('patchState', () => {
   const initialState = {
@@ -11,67 +12,83 @@ describe('patchState', () => {
     ngrx: 'signals',
   };
 
-  it('patches state via partial state object', () => {
-    const state = signalState(initialState);
+  [
+    {
+      name: 'with signalState',
+      stateFactory: () => signalState(initialState),
+    },
+    {
+      name: 'with signalStore',
+      stateFactory: () => {
+        const SignalStore = signalStore(withState(initialState));
+        return new SignalStore();
+      },
+    },
+  ].forEach(({ name, stateFactory }) => {
+    describe(name, () => {
+      it('patches state via partial state object', () => {
+        const state = stateFactory();
 
-    patchState(state, {
-      user: { firstName: 'Johannes', lastName: 'Schmidt' },
-      foo: 'baz',
-    });
+        patchState(state, {
+          user: { firstName: 'Johannes', lastName: 'Schmidt' },
+          foo: 'baz',
+        });
 
-    expect(state()).toEqual({
-      ...initialState,
-      user: { firstName: 'Johannes', lastName: 'Schmidt' },
-      foo: 'baz',
-    });
-  });
+        expect(state[STATE_SIGNAL]()).toEqual({
+          ...initialState,
+          user: { firstName: 'Johannes', lastName: 'Schmidt' },
+          foo: 'baz',
+        });
+      });
 
-  it('patches state via updater function', () => {
-    const state = signalState(initialState);
+      it('patches state via updater function', () => {
+        const state = stateFactory();
 
-    patchState(state, (state) => ({
-      numbers: [...state.numbers, 4],
-      ngrx: 'rocks',
-    }));
+        patchState(state, (state) => ({
+          numbers: [...state.numbers, 4],
+          ngrx: 'rocks',
+        }));
 
-    expect(state()).toEqual({
-      ...initialState,
-      numbers: [1, 2, 3, 4],
-      ngrx: 'rocks',
-    });
-  });
+        expect(state[STATE_SIGNAL]()).toEqual({
+          ...initialState,
+          numbers: [1, 2, 3, 4],
+          ngrx: 'rocks',
+        });
+      });
 
-  it('patches state via sequence of partial state objects and updater functions', () => {
-    const state = signalState(initialState);
+      it('patches state via sequence of partial state objects and updater functions', () => {
+        const state = stateFactory();
 
-    patchState(
-      state,
-      { user: { firstName: 'Johannes', lastName: 'Schmidt' } },
-      (state) => ({ numbers: [...state.numbers, 4], foo: 'baz' }),
-      (state) => ({ user: { ...state.user, firstName: 'Jovan' } }),
-      { foo: 'foo' }
-    );
+        patchState(
+          state,
+          { user: { firstName: 'Johannes', lastName: 'Schmidt' } },
+          (state) => ({ numbers: [...state.numbers, 4], foo: 'baz' }),
+          (state) => ({ user: { ...state.user, firstName: 'Jovan' } }),
+          { foo: 'foo' }
+        );
 
-    expect(state()).toEqual({
-      ...initialState,
-      user: { firstName: 'Jovan', lastName: 'Schmidt' },
-      foo: 'foo',
-      numbers: [1, 2, 3, 4],
-    });
-  });
+        expect(state[STATE_SIGNAL]()).toEqual({
+          ...initialState,
+          user: { firstName: 'Jovan', lastName: 'Schmidt' },
+          foo: 'foo',
+          numbers: [1, 2, 3, 4],
+        });
+      });
 
-  it('patches state immutably', () => {
-    const state = signalState(initialState);
+      it('patches state immutably', () => {
+        const state = stateFactory();
 
-    patchState(state, {
-      foo: 'bar',
-      numbers: [3, 2, 1],
-      ngrx: 'rocks',
-    });
+        patchState(state, {
+          foo: 'bar',
+          numbers: [3, 2, 1],
+          ngrx: 'rocks',
+        });
 
-    expect(state.user()).toBe(initialState.user);
-    expect(state.foo()).toBe(initialState.foo);
-    expect(state.numbers()).not.toBe(initialState.numbers);
-    expect(state.ngrx()).not.toBe(initialState.ngrx);
+        expect(state.user()).toBe(initialState.user);
+        expect(state.foo()).toBe(initialState.foo);
+        expect(state.numbers()).not.toBe(initialState.numbers);
+        expect(state.ngrx()).not.toBe(initialState.ngrx);
+      });
+    });
   });
 });

modules/signals/spec/signal-state.spec.ts

@@ -1,5 +1,6 @@
 import { effect, isSignal } from '@angular/core';
 import { patchState, signalState } from '../src';
+import { STATE_SIGNAL } from '../src/signal-state';
 import { testEffects } from './helpers';
 
 describe('signalState', () => {
@@ -13,6 +14,14 @@ describe('signalState', () => {
     ngrx: 'signals',
   };
 
+  it('has state signal', () => {
+    const state = signalState({});
+    const stateSignal = state[STATE_SIGNAL];
+
+    expect(isSignal(stateSignal)).toBe(true);
+    expect(typeof stateSignal.update === 'function').toBe(true);
+  });
+
   it('creates signals for nested state slices', () => {
     const state = signalState(initialState);
 

modules/signals/spec/signal-store-feature.spec.ts

@@ -0,0 +1,94 @@
+import { Signal, signal } from '@angular/core';
+import {
+  selectSignal,
+  signalStore,
+  signalStoreFeature,
+  type,
+  withMethods,
+  withSignals,
+  withState,
+} from '../src';
+import { STATE_SIGNAL } from '../src/signal-state';
+
+describe('signalStoreFeature', () => {
+  function withCustomFeature1() {
+    return signalStoreFeature(
+      withState({ foo: 'foo' }),
+      withSignals(({ foo }) => ({ bar: selectSignal(() => foo() + 1) })),
+      withMethods(({ foo, bar }) => ({
+        baz: () => foo() + bar() + 2,
+      }))
+    );
+  }
+
+  function withCustomFeature2() {
+    return signalStoreFeature(
+      withCustomFeature1(),
+      withMethods(({ foo, baz }) => ({
+        bar: (value: number) => value,
+        m: () => foo() + baz() + 3,
+      }))
+    );
+  }
+
+  function withCustomFeatureWithInput<_>() {
+    return signalStoreFeature(
+      {
+        state: type<{ foo: string }>(),
+        signals: type<{ s: Signal<number> }>(),
+      },
+      withState({ foo1: 1 }),
+      withState({ foo2: 2 })
+    );
+  }
+
+  it('creates a custom feature by combining base features', () => {
+    const Store = signalStore(
+      withCustomFeature1(),
+      withSignals(({ bar }) => ({
+        s: selectSignal(() => bar() + 's'),
+      }))
+    );
+
+    const store = new Store();
+
+    expect(store[STATE_SIGNAL]()).toEqual({ foo: 'foo' });
+    expect(store.foo()).toBe('foo');
+    expect(store.bar()).toBe('foo1');
+    expect(store.baz()).toBe('foofoo12');
+    expect(store.s()).toBe('foo1s');
+  });
+
+  it('creates a custom feature by combining base and custom features', () => {
+    const Store = signalStore(
+      withCustomFeature2(),
+      withMethods(({ foo }) => ({ m1: () => foo() + 10 }))
+    );
+
+    const store = new Store();
+
+    expect(store[STATE_SIGNAL]()).toEqual({ foo: 'foo' });
+    expect(store.foo()).toBe('foo');
+    expect(store.bar(10)).toBe(10);
+    expect(store.m()).toBe('foofoofoo123');
+    expect(store.m1()).toBe('foo10');
+  });
+
+  it('creates a custom feature with input', () => {
+    const Store = signalStore(
+      withCustomFeature1(),
+      withSignals(() => ({ s: signal(1).asReadonly() })),
+      withCustomFeatureWithInput()
+    );
+
+    const store = new Store();
+
+    expect(store[STATE_SIGNAL]()).toEqual({ foo: 'foo', foo1: 1, foo2: 2 });
+    expect(store.foo()).toBe('foo');
+    expect(store.bar()).toBe('foo1');
+    expect(store.baz()).toBe('foofoo12');
+    expect(store.s()).toBe(1);
+    expect(store.foo1()).toBe(1);
+    expect(store.foo2()).toBe(2);
+  });
+});