feat: allow properties in selectors

modules/store/spec/selector.spec.ts

@@ -123,6 +123,106 @@ describe('Selectors', () => {
     });
   });
 
+  describe('createSelector with props', () => {
+    it('should deliver the value of selectors to the projection function', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+
+      const selector = createSelector(
+        incrementOne,
+        incrementTwo,
+        (state: any, props: any) => props.value,
+        projectFn
+      );
+
+      selector({}, { value: 47 });
+      expect(projectFn).toHaveBeenCalledWith(countOne, countTwo, 47);
+    });
+
+    it('should be possible to test a projector fn independent from the selectors it is composed of', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        incrementOne,
+        incrementTwo,
+        (state: any, props: any) => {
+          fail(`Shouldn't be called`);
+          return props.value;
+        },
+        projectFn
+      );
+      selector.projector('', '', 47);
+
+      expect(incrementOne).not.toHaveBeenCalled();
+      expect(incrementTwo).not.toHaveBeenCalled();
+      expect(projectFn).toHaveBeenCalledWith('', '', 47);
+    });
+
+    it('should call the projector function when the property changes', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        incrementOne,
+        (state: any, props: any) => props.value,
+        projectFn
+      );
+
+      const state1 = { foo: 'bar' };
+      const props1 = { foo: 'bar' };
+      selector(state1, props1);
+      selector(state1, props1);
+      expect(projectFn).toHaveBeenCalledTimes(1);
+
+      const props2 = { foo: 'bar2' };
+      selector(state1, props2);
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+
+    it('should memoize the function', () => {
+      let counter = 0;
+
+      const firstState = { first: 'state' };
+      const firstProps = { foo: 'first' };
+      const secondProps = { foo: 'second' };
+
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        incrementOne,
+        incrementTwo,
+        (state: any, props: any) => {
+          counter++;
+          return props;
+        },
+        projectFn
+      );
+
+      selector(firstState, firstProps);
+      selector(firstState, firstProps);
+      selector(firstState, firstProps);
+      selector(firstState, secondProps);
+      selector(firstState, secondProps);
+
+      expect(counter).toBe(2);
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+
+    it('should allow you to release memoized arguments', () => {
+      const state = { first: 'state' };
+      const props = { first: 'props' };
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        incrementOne,
+        (state: any, props: any) => props,
+        projectFn
+      );
+
+      selector(state, props);
+      selector(state, props);
+      selector.release();
+      selector(state, props);
+      selector(state, props);
+
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+  });
+
   describe('createSelector with arrays', () => {
     it('should deliver the value of selectors to the projection function', () => {
       const projectFn = jasmine.createSpy('projectionFn');
@@ -209,6 +309,105 @@ describe('Selectors', () => {
     });
   });
 
+  describe('createSelector with arrays and props', () => {
+    it('should deliver the value of selectors to the projection function', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        [incrementOne, incrementTwo, (state: any, props: any) => props.value],
+        projectFn
+      )({}, { value: 47 });
+
+      expect(projectFn).toHaveBeenCalledWith(countOne, countTwo, 47);
+    });
+
+    it('should be possible to test a projector fn independent from the selectors it is composed of', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        [
+          incrementOne,
+          incrementTwo,
+          (state: any, props: any) => {
+            fail(`Shouldn't be called`);
+            return props.value;
+          },
+        ],
+        projectFn
+      );
+
+      selector.projector('', '', 47);
+
+      expect(incrementOne).not.toHaveBeenCalled();
+      expect(incrementTwo).not.toHaveBeenCalled();
+      expect(projectFn).toHaveBeenCalledWith('', '', 47);
+    });
+
+    it('should call the projector function when the property changes', () => {
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        [incrementOne, (state: any, props: any) => props.value],
+        projectFn
+      );
+
+      const state1 = { foo: 'bar' };
+      const props1 = { foo: 'bar' };
+      selector(state1, props1);
+      selector(state1, props1);
+      expect(projectFn).toHaveBeenCalledTimes(1);
+
+      const props2 = { foo: 'bar2' };
+      selector(state1, props2);
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+
+    it('should memoize the function', () => {
+      let counter = 0;
+
+      const firstState = { first: 'state' };
+      const firstProps = { foo: 'first' };
+      const secondProps = { foo: 'second' };
+
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        [
+          incrementOne,
+          incrementTwo,
+          (state: any, props: any) => {
+            counter++;
+            return props;
+          },
+        ],
+        projectFn
+      );
+
+      selector(firstState, firstProps);
+      selector(firstState, firstProps);
+      selector(firstState, firstProps);
+      selector(firstState, secondProps);
+      selector(firstState, secondProps);
+
+      expect(counter).toBe(2);
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+
+    it('should allow you to release memoized arguments', () => {
+      const state = { first: 'state' };
+      const props = { first: 'props' };
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        [incrementOne, (state: any, props: any) => props],
+        projectFn
+      );
+
+      selector(state, props);
+      selector(state, props);
+      selector.release();
+      selector(state, props);
+      selector(state, props);
+
+      expect(projectFn).toHaveBeenCalledTimes(2);
+    });
+  });
+
   describe('createFeatureSelector', () => {
     let featureName = '@ngrx/router-store';
     let featureSelector: (state: any) => number;

modules/store/src/models.ts

@@ -33,6 +33,9 @@ export interface StoreFeature<T, V extends Action = Action> {
   metaReducers?: MetaReducer<T, V>[];
 }
 
-export interface Selector<T, V> {
-  (state: T): V;
-}
+export type Selector<State, Result> = (state: State) => Result;
+
+export type SelectorWithProperty<State, Property, Result> = (
+  state: State,
+  props: Property
+) => Result;