todo-list.component.spec.ts

import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { BrowserModule } from '@angular/platform-browser';
import { NO_ERRORS_SCHEMA } from '@angular/core';
import { TodoListComponent } from './todo-list.component';
import { TodoListService } from '../core/todo-list.service';
import { TODOItem } from '../shared/models/todo-item';

describe('TodoListComponent', () => {
  let component: TodoListComponent;
  let fixture: ComponentFixture<TodoListComponent>;

  beforeEach(async(() => {

    const todo1 = new TODOItem('Buy milk', 'Remember to buy milk');
    todo1.completed = true;
    const todoList = [
      todo1,
      new TODOItem('Buy flowers', 'Remember to buy flowers'),
    ];

    TestBed.configureTestingModule({
      declarations: [
        TodoListComponent,
    ],
      imports: [
        BrowserModule,
      ],
      providers: [
      {
        provide: TodoListService,
        useValue: {todoList: todoList}
      }
    ],
    schemas: [NO_ERRORS_SCHEMA]
    })
    .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(TodoListComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });

  it('should have two completed TODO item', () => {
    expect(component.todoList.length).toBe(2);
  });
});