Testing Simple Actions

Consider the following simple actions, from the Redux chapter of this book:

  1. import { Injectable } from '@angular/core';
  2. import { NgRedux } from 'ng2-redux';
  4. export const INCREMENT_COUNTER = 'INCREMENT_COUNTER';
  5. export const DECREMENT_COUNTER = 'DECREMENT_COUNTER';
  7. @Injectable
  8. export class CounterActions {
  9.   constructor(private redux: NgRedux<any>) {}
  11.   increment() {
  12.     this.redux.dispatch({ type: INCREMENT_COUNTER });
  13.   }
  15.   decrement() {
  16.     this.redux.dispatch({ type: DECREMENT_COUNTER });
  17.   }
  18. }

These are pretty straightforward to test:

  1. import { NgRedux } from 'ng2-redux';
  2. import {
  3.   CounterActions,
  4.   INCREMENT_COUNTER,
  5.   DECREMENT_COUNTER,
  6. } from './counter';
  8. // Mock out the NgRedux class with just enough to test what we want.
  9. class MockRedux extends NgRedux<any> {
  10.   constructor() {
  11.     super(null);
  12.   }
  13.   dispatch = () => undefined;
  14. }
  16. describe('counter action creators', () => {
  17.   let actions: CounterActions;
  18.   let mockRedux: NgRedux<any>;
  20.   beforeEach(() => {
  21.     // Initialize mock NgRedux and create a new instance of the
  22.     // ActionCreatorService to be tested.
  23.     mockRedux = new MockRedux();
  24.     actions = new CounterActions(mockRedux);
  25.   });
  27.   it('increment should dispatch INCREMENT_COUNTER action', () => {
  28.     const expectedAction = {
  29.       type: INCREMENT_COUNTER
  30.     };
  32.     spyOn(mockRedux, 'dispatch');
  33.     actions.increment();
  35.     expect(mockRedux.dispatch).toHaveBeenCalled();
  36.     expect(mockRedux.dispatch).toHaveBeenCalledWith(expectedAction);
  37.   });
  39.   it('decrement should dispatch DECREMENT_COUNTER action', () => {
  40.     const expectedAction = {
  41.       type: DECREMENT_COUNTER
  42.     };
  44.     spyOn(mockRedux, 'dispatch');
  45.     actions.decrement();
  47.     expect(mockRedux.dispatch).toHaveBeenCalled();
  48.     expect(mockRedux.dispatch).toHaveBeenCalledWith(expectedAction);
  49.   });
  50. });

We just make sure that our action creators do indeed dispatch the correct actions.

原文: https://angular-2-training-book.rangle.io/handout/testing/redux/simple-actions.html