added tests for hostReducer and Header Effects, and switch to typed actions

.gitignore

@@ -6,6 +6,7 @@
 npm-debug.log
 
 /dist/
+/coverage/
 
 .idea
 *.ngfactory.ts

src/app/app.component.ts

@@ -8,7 +8,7 @@ import {
 import { TranslateService } from "ng2-translate";
 import { HostWindowState } from "./shared/host-window.reducer";
 import { Store } from "@ngrx/store";
-import { HostWindowActions } from "./shared/host-window.actions";
+import { HostWindowResizeAction } from "./shared/host-window.actions";
 
 @Component({
   changeDetection: ChangeDetectionStrategy.Default,
@@ -52,7 +52,7 @@ export class AppComponent implements OnDestroy, OnInit {
   @HostListener('window:resize', ['$event'])
   private onResize(event): void {
     this.store.dispatch(
-      HostWindowActions.resize(event.target.innerWidth, event.target.innerHeight)
+      new HostWindowResizeAction(event.target.innerWidth, event.target.innerHeight)
     );
   }
 

src/app/header/header.actions.spec.ts

@@ -1,22 +0,0 @@
-import { HeaderActions } from "./header.actions";
-describe("HeaderActions", () => {
-
-  describe("collapse", () => {
-    it("should return a COLLAPSE action", () => {
-      expect(HeaderActions.collapse().type).toEqual(HeaderActions.COLLAPSE);
-    });
-  });
-
-  describe("expand", () => {
-    it("should return an EXPAND action", () => {
-      expect(HeaderActions.expand().type).toEqual(HeaderActions.EXPAND);
-    });
-  });
-
-  describe("toggle", () => {
-    it("should return a TOGGLE action", () => {
-      expect(HeaderActions.toggle().type).toEqual(HeaderActions.TOGGLE);
-    });
-  })
-
-});

src/app/header/header.actions.ts

@@ -1,24 +1,43 @@
 import { Action } from "@ngrx/store";
+import { type } from "../shared/ngrx/type";
 
-export class HeaderActions {
-  static COLLAPSE = 'dspace/header/COLLAPSE';
-  static collapse(): Action {
-    return {
-      type: HeaderActions.COLLAPSE
-    }
-  }
+ /**
+ * For each action type in an action group, make a simple
+ * enum object for all of this group's action types.
+ *
+ * The 'type' utility function coerces strings into string
+ * literal types and runs a simple check to guarantee all
+ * action types in the application are unique.
+ */
+export const HeaderActionTypes = {
+  COLLAPSE: type('dspace/header/COLLAPSE'),
+  EXPAND: type('dspace/header/EXPAND'),
+  TOGGLE: type('dspace/header/TOGGLE')
+};
 
-  static EXPAND = 'dspace/header/EXPAND';
-  static expand(): Action {
-    return {
-      type: HeaderActions.EXPAND
-    }
-  }
+export class HeaderCollapseAction implements Action {
+  type = HeaderActionTypes.COLLAPSE;
 
-  static TOGGLE = 'dspace/header/TOGGLE';
-  static toggle(): Action {
-    return {
-      type: HeaderActions.TOGGLE
-    }
-  }
+  constructor() {}
 }
+
+export class HeaderExpandAction implements Action {
+  type = HeaderActionTypes.EXPAND;
+
+  constructor() {}
+}
+
+export class HeaderToggleAction implements Action {
+  type = HeaderActionTypes.TOGGLE;
+
+  constructor() {}
+}
+
+/**
+ * Export a type alias of all actions in this action group
+ * so that reducers can easily compose action types
+ */
+export type HeaderAction
+  = HeaderCollapseAction
+  | HeaderExpandAction
+  | HeaderToggleAction

src/app/header/header.component.ts

@@ -1,9 +1,12 @@
 import { Component, OnInit } from "@angular/core";
 import { Store } from "@ngrx/store";
 import { HeaderState } from "./header.reducer";
-import { HeaderActions } from "./header.actions";
 import { Observable } from "rxjs";
-import 'rxjs/add/operator/filter';
+import {
+  HeaderCollapseAction,
+  HeaderExpandAction,
+  HeaderToggleAction
+} from "./header.actions";
 
 @Component({
   selector: 'ds-header',
@@ -25,15 +28,15 @@ export class HeaderComponent implements OnInit {
   }
 
   private collapse(): void {
-    this.store.dispatch(HeaderActions.collapse());
+    this.store.dispatch(new HeaderCollapseAction());
   }
 
   private expand(): void {
-    this.store.dispatch(HeaderActions.expand());
+    this.store.dispatch(new HeaderExpandAction());
   }
 
   public toggle(): void {
-    this.store.dispatch(HeaderActions.toggle());
+    this.store.dispatch(new HeaderToggleAction());
   }
 
 }

src/app/header/header.effects.spec.ts

@@ -0,0 +1,53 @@
+import { TestBed, inject } from "@angular/core/testing";
+import { EffectsTestingModule, EffectsRunner } from '@ngrx/effects/testing';
+import { HeaderEffects } from "./header.effects";
+import { HeaderCollapseAction } from "./header.actions";
+import { HostWindowResizeAction } from "../shared/host-window.actions";
+import { routerActions } from "@ngrx/router-store";
+
+describe('HeaderEffects', () => {
+  beforeEach(() => TestBed.configureTestingModule({
+    imports: [
+      EffectsTestingModule
+    ],
+    providers: [
+      HeaderEffects
+    ]
+  }));
+
+  let runner: EffectsRunner;
+  let headerEffects: HeaderEffects;
+
+  beforeEach(inject([
+      EffectsRunner, HeaderEffects
+    ],
+    (_runner, _headerEffects) => {
+      runner = _runner;
+      headerEffects = _headerEffects;
+    }
+  ));
+
+  describe('resize$', () => {
+
+    it('should return a COLLAPSE action in response to a RESIZE action', () => {
+      runner.queue(new HostWindowResizeAction(800,600));
+
+      headerEffects.resize$.subscribe(result => {
+        expect(result).toEqual(new HeaderCollapseAction());
+      });
+    });
+
+  });
+
+  describe('routeChange$', () => {
+
+    it('should return a COLLAPSE action in response to an UPDATE_LOCATION action', () => {
+      runner.queue({ type: routerActions.UPDATE_LOCATION });
+
+      headerEffects.resize$.subscribe(result => {
+        expect(result).toEqual(new HeaderCollapseAction());
+      });
+    });
+
+  });
+});

src/app/header/header.effects.ts

@@ -1,8 +1,8 @@
 import { Injectable } from "@angular/core";
 import { Effect, Actions } from '@ngrx/effects'
-import { HeaderActions } from "./header.actions";
-import { HostWindowActions } from "../shared/host-window.actions";
+import { HostWindowActionTypes } from "../shared/host-window.actions";
 import { routerActions } from "@ngrx/router-store";
+import { HeaderCollapseAction } from "./header.actions";
 
 @Injectable()
 export class HeaderEffects {
@@ -12,10 +12,10 @@ export class HeaderEffects {
   ) { }
 
   @Effect() resize$ = this.actions$
-    .ofType(HostWindowActions.RESIZE)
-    .map(() => HeaderActions.collapse());
+    .ofType(HostWindowActionTypes.RESIZE)
+    .map(() => new HeaderCollapseAction());
 
   @Effect() routeChange$ = this.actions$
     .ofType(routerActions.UPDATE_LOCATION)
-    .map(() => HeaderActions.collapse());
+    .map(() => new HeaderCollapseAction());
 }

src/app/header/header.reducer.spec.ts

@@ -1,19 +1,25 @@
 import * as deepFreeze from "deep-freeze";
 
 import { headerReducer } from "./header.reducer";
-import { HeaderActions } from "./header.actions";
+import {
+  HeaderCollapseAction,
+  HeaderExpandAction,
+  HeaderToggleAction
+} from "./header.actions";
 
 describe("headerReducer", () => {
+  let nullAction = new HeaderCollapseAction();
+  nullAction.type = null;
 
   it("should return the current state when no valid actions have been made", () => {
     const state = { navCollapsed: false };
-    const newState = headerReducer(state, {type: 'undefined-action'});
+    const newState = headerReducer(state, nullAction);
 
     expect(newState).toEqual(state);
   });
 
   it("should start with navCollapsed = true", () => {
-    const initialState = headerReducer(undefined, {type: 'undefined-action'});
+    const initialState = headerReducer(undefined, nullAction);
 
     // The navigation starts collapsed
     expect(initialState.navCollapsed).toEqual(true);
@@ -21,7 +27,7 @@ describe("headerReducer", () => {
 
   it("should set navCollapsed to true in response to the COLLAPSE action", () => {
     const state = { navCollapsed: false };
-    const action = HeaderActions.collapse();
+    const action = new HeaderCollapseAction();
     const newState = headerReducer(state, action);
 
     expect(newState.navCollapsed).toEqual(true);
@@ -31,7 +37,7 @@ describe("headerReducer", () => {
     const state = { navCollapsed: false };
     deepFreeze(state);
 
-    const action = HeaderActions.collapse();
+    const action = new HeaderCollapseAction();
     headerReducer(state, action);
 
     //no expect required, deepFreeze will ensure an exception is thrown if the state
@@ -40,7 +46,7 @@ describe("headerReducer", () => {
 
   it("should set navCollapsed to false in response to the EXPAND action", () => {
     const state = { navCollapsed: true };
-    const action = HeaderActions.expand();
+    const action = new HeaderExpandAction();
     const newState = headerReducer(state, action);
 
     expect(newState.navCollapsed).toEqual(false);
@@ -50,13 +56,13 @@ describe("headerReducer", () => {
     const state = { navCollapsed: true };
     deepFreeze(state);
 
-    const action = HeaderActions.expand();
+    const action = new HeaderExpandAction();
     headerReducer(state, action);
   });
 
   it("should flip the value of navCollapsed in response to the TOGGLE action", () => {
     const state1 = { navCollapsed: true };
-    const action = HeaderActions.toggle();
+    const action = new HeaderToggleAction();
 
     const state2 = headerReducer(state1, action);
     const state3 = headerReducer(state2, action);
@@ -69,7 +75,7 @@ describe("headerReducer", () => {
     const state = { navCollapsed: true };
     deepFreeze(state);
 
-    const action = HeaderActions.toggle();
+    const action = new HeaderToggleAction();
     headerReducer(state, action);
   });
 

src/app/header/header.reducer.ts

@@ -1,5 +1,4 @@
-import { Action } from "@ngrx/store";
-import { HeaderActions } from "./header.actions";
+import { HeaderAction, HeaderActionTypes } from "./header.actions";
 
 export interface HeaderState {
   navCollapsed: boolean;
@@ -9,23 +8,23 @@ const initialState: HeaderState = {
   navCollapsed: true
 };
 
-export const headerReducer = (state = initialState, action: Action): HeaderState => {
+export const headerReducer = (state = initialState, action: HeaderAction): HeaderState => {
   switch (action.type) {
 
-    case HeaderActions.COLLAPSE: {
+    case HeaderActionTypes.COLLAPSE: {
       return Object.assign({}, state, {
         navCollapsed: true
       });
     }
 
-    case HeaderActions.EXPAND: {
+    case HeaderActionTypes.EXPAND: {
       return Object.assign({}, state, {
         navCollapsed: false
       });
 
     }
 
-    case HeaderActions.TOGGLE: {
+    case HeaderActionTypes.TOGGLE: {
       return Object.assign({}, state, {
         navCollapsed: !state.navCollapsed
       });

src/app/shared/host-window.actions.ts

@@ -1,14 +1,21 @@
 import { Action } from "@ngrx/store";
+import { type } from "./ngrx/type";
 
-export class HostWindowActions {
-  static RESIZE = 'dspace/host-window/RESIZE';
-  static resize(newWidth: number, newHeight: number): Action {
-    return {
-      type: HostWindowActions.RESIZE,
-      payload: {
-        width: newWidth,
-        height: newHeight
-      }
-    }
+export const HostWindowActionTypes = {
+  RESIZE: type('dspace/host-window/RESIZE')
+};
+
+export class HostWindowResizeAction implements Action {
+  type = HostWindowActionTypes.RESIZE;
+  payload: {
+    width: number;
+    height: number;
+  };
+
+  constructor(width: number, height: number) {
+    this.payload = { width, height }
   }
 }
+
+export type HostWindowAction
+  = HostWindowResizeAction;

src/app/shared/host-window.reducer.spec.ts

@@ -0,0 +1,40 @@
+import * as deepFreeze from "deep-freeze";
+import { hostWindowReducer } from "./host-window.reducer";
+import { HostWindowResizeAction } from "./host-window.actions";
+
+describe('hostWindowReducer', () => {
+  let nullAction = new HostWindowResizeAction(0, 0);
+  nullAction.type = null;
+
+  it("should return the current state when no valid actions have been made", () => {
+    const state = { width: 800, height: 600 };
+    const newState = hostWindowReducer(state, nullAction);
+
+    expect(newState).toEqual(state);
+  });
+
+  it("should start with width = null and height = null", () => {
+    const initialState = hostWindowReducer(undefined, nullAction);
+
+    expect(initialState.width).toEqual(null);
+    expect(initialState.height).toEqual(null);
+  });
+
+  it("should update the width and height in the state in response to a RESIZE action", () => {
+    const state = { width: 800, height: 600 };
+    const action = new HostWindowResizeAction(1024, 768);
+    const newState = hostWindowReducer(state, action);
+
+    expect(newState.width).toEqual(1024);
+    expect(newState.height).toEqual(768);
+  });
+
+  it("should perform the RESIZE action without mutating the previous state", () => {
+    const state = { width: 800, height: 600 };
+    deepFreeze(state);
+
+    const action = new HostWindowResizeAction(1024, 768);
+    hostWindowReducer(state, action);
+  });
+
+});

src/app/shared/host-window.reducer.ts

@@ -1,5 +1,4 @@
-import { Action } from "@ngrx/store";
-import { HostWindowActions } from "./host-window.actions";
+import { HostWindowAction, HostWindowActionTypes } from "./host-window.actions";
 
 export interface HostWindowState {
   width: number;
@@ -11,10 +10,10 @@ const initialState: HostWindowState = {
   height: null
 };
 
-export const hostWindowReducer = (state = initialState, action: Action): HostWindowState => {
+export const hostWindowReducer = (state = initialState, action: HostWindowAction): HostWindowState => {
   switch (action.type) {
 
-    case HostWindowActions.RESIZE: {
+    case HostWindowActionTypes.RESIZE: {
       return Object.assign({}, state, action.payload);
     }
 

src/app/shared/ngrx/type.ts

@@ -0,0 +1,24 @@
+
+/**
+ * Based on
+ * https://github.com/ngrx/example-app/blob/master/src/app/util.ts
+ *
+ * This function coerces a string into a string literal type.
+ * Using tagged union types in TypeScript 2.0, this enables
+ * powerful typechecking of our reducers.
+ *
+ * Since every action label passes through this function it
+ * is a good place to ensure all of our action labels
+ * are unique.
+ */
+
+let typeCache: { [label: string]: boolean } = {};
+export function type<T>(label: T | ''): T {
+  if (typeCache[<string>label]) {
+    throw new Error(`Action type "${label}" is not unique"`);
+  }
+
+  typeCache[<string>label] = true;
+
+  return <T>label;
+}