fix(Store): selector with only a projector (#1579)

Closes #1558 

BREAKING CHANGE:

Selectors with only a projector function aren't valid anymore.
This change will make the usage more consistent.

BEFORE:

```
const getTodosById = createSelector(
  (state: TodoAppSchema, id: number) => state.todos.find(p => p.id === id)
);
```

AFTER:

```
const getTodosById = createSelector(
  (state: TodoAppSchema) => state.todos,
  (todos: Todo[], id: number) => todos.find(p => p.id === id)
);
```

Author: timdeschryver

modules/store/spec/integration.spec.ts

@@ -179,8 +179,9 @@ describe('ngRx Integration spec', () => {
 
       it('should use props to get a todo', () => {
         const getTodosById = createSelector(
-          (state: TodoAppSchema, id: number) => {
-            return state.todos.find(p => p.id === id);
+          (state: TodoAppSchema) => state.todos,
+          (todos: Todo[], id: number) => {
+            return todos.find(p => p.id === id);
           }
         );
 
@@ -252,46 +253,6 @@ describe('ngRx Integration spec', () => {
           payload: { id: 2 },
         });
       });
-
-      it('should use the props in the projector to get a todo', () => {
-        const getTodosState = createFeatureSelector<TodoAppSchema, Todo[]>(
-          'todos'
-        );
-
-        const getTodosById = createSelector(
-          getTodosState,
-          (todos: Todo[], { id }: { id: number }) =>
-            todos.find(todo => todo.id === id)
-        );
-
-        let testCase = 1;
-        const todo$ = store.pipe(select(getTodosById, { id: 2 }));
-        todo$.subscribe(todo => {
-          if (testCase === 1) {
-            expect(todo).toEqual(undefined);
-          } else if (testCase === 2) {
-            expect(todo).toEqual({
-              id: 2,
-              text: 'second todo',
-              completed: false,
-            });
-          } else if (testCase === 3) {
-            expect(todo).toEqual({
-              id: 2,
-              text: 'second todo',
-              completed: true,
-            });
-          }
-          testCase++;
-        });
-
-        store.dispatch({ type: ADD_TODO, payload: { text: 'first todo' } });
-        store.dispatch({ type: ADD_TODO, payload: { text: 'second todo' } });
-        store.dispatch({
-          type: COMPLETE_TODO,
-          payload: { id: 2 },
-        });
-      });
     });
 
     describe('using the select operator', () => {
@@ -357,42 +318,6 @@ describe('ngRx Integration spec', () => {
         expect(currentlyVisibleTodos.length).toBe(0);
       });
 
-      it('should use props to get a todo', () => {
-        const getTodosById = createSelector(
-          (state: TodoAppSchema, id: number) => {
-            return state.todos.find(p => p.id === id);
-          }
-        );
-
-        let testCase = 1;
-        const todo$ = store.pipe(select(getTodosById, 2));
-        todo$.subscribe(todo => {
-          if (testCase === 1) {
-            expect(todo).toEqual(undefined);
-          } else if (testCase === 2) {
-            expect(todo).toEqual({
-              id: 2,
-              text: 'second todo',
-              completed: false,
-            });
-          } else if (testCase === 3) {
-            expect(todo).toEqual({
-              id: 2,
-              text: 'second todo',
-              completed: true,
-            });
-          }
-          testCase++;
-        });
-
-        store.dispatch({ type: ADD_TODO, payload: { text: 'first todo' } });
-        store.dispatch({ type: ADD_TODO, payload: { text: 'second todo' } });
-        store.dispatch({
-          type: COMPLETE_TODO,
-          payload: { id: 2 },
-        });
-      });
-
       it('should use the selector and props to get a todo', () => {
         const getTodosState = createFeatureSelector<TodoAppSchema, Todo[]>(
           'todos'

modules/store/spec/selector.spec.ts

@@ -143,17 +143,6 @@ describe('Selectors', () => {
       });
     });
 
-    it('should not short circuit to the projector fn if there are no selectors and props', () => {
-      const projectFn = jasmine.createSpy('projectionFn');
-      const state = { counter: {} };
-
-      const selector = (createSelector(projectFn) as any)(state);
-
-      // the projector still fires but without arguments,
-      // this because there are no selectors and props
-      expect(projectFn).toHaveBeenCalledWith();
-    });
-
     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(
@@ -239,51 +228,6 @@ describe('Selectors', () => {
     });
   });
 
-  describe('createSelector with only a props selector', () => {
-    it('should deliver the state and the props to the projection function', () => {
-      const projectFn = jasmine.createSpy('projectionFn');
-      const state = { counter: {} };
-      const props = { value: 47 };
-      const selector = createSelector(projectFn)(state, props);
-      expect(projectFn).toHaveBeenCalledWith(state, props);
-    });
-
-    it('should be possible to use a projector fn', () => {
-      const projectFn = jasmine.createSpy('projectionFn');
-      const selector = createSelector(projectFn);
-      selector.projector('foo', 'bar');
-      expect(projectFn).toHaveBeenCalledWith('foo', 'bar');
-    });
-
-    it('should call the projector function when the state changes', () => {
-      const projectFn = jasmine.createSpy('projectionFn');
-      const selector = createSelector(projectFn);
-
-      const firstState = { first: 'state' };
-      const secondState = { second: 'state' };
-      const props = { foo: 'props' };
-      selector(firstState, props);
-      selector(firstState, props);
-      selector(secondState, props);
-      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(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');

modules/store/src/selector.ts

@@ -472,31 +472,6 @@ export function createSelector<
   ) => Result
 ): MemoizedSelectorWithProps<State, Props, Result>;
 
-/**
- * @deprecated
- * Selectors with only a projector function aren't valid anymore and will be removed in version 8.0.0
- *
- * BEFORE:
- *
- * ```ts
- * const getTodosById = createSelector(
- *   (state: TodoAppSchema, id: number) => state.todos.find(p => p.id === id)
- * );
- * ```
- *
- * AFTER:
- *
- * ```ts
- * const getTodosById = createSelector(
- *   (state: TodoAppSchema) => state.todos,
- *   (todos: Todo[], id: number) => todos.find(p => p.id === id)
- * );
- * ```
- */
-export function createSelector<State, Props, Result>(
-  projector: SelectorWithProps<State, Props, Result>
-): MemoizedSelectorWithProps<State, Props, Result>;
-
 export function createSelector(
   ...input: any[]
 ): Selector<any, any> | SelectorWithProps<any, any, any> {
@@ -570,12 +545,6 @@ export function createSelectorFactory(
     });
 
     const memoizedState = defaultMemoize(function(state: any, props: any) {
-      // createSelector works directly on state
-      // e.g. createSelector((state, props) => ...)
-      if (selectors.length === 0 && props !== undefined) {
-        return projector.apply(null, [state, props]);
-      }
-
       return options.stateFn.apply(null, [
         state,
         selectors,