angular-cn/public/docs/_examples/testing/ts/app/welcome.component.spec.ts

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3.7 KiB
TypeScript

// #docplaster
import { ComponentFixture, inject, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { UserService } from './model';
import { WelcomeComponent } from './welcome.component';
describe('WelcomeComponent', () => {
let comp: WelcomeComponent;
let fixture: ComponentFixture<WelcomeComponent>;
let componentUserService: UserService; // the actually injected service
let userService: UserService; // the TestBed injected service
let de: DebugElement; // the DebugElement with the welcome message
let el: HTMLElement; // the DOM element with the welcome message
let userServiceStub: {
isLoggedIn: boolean;
user: { name: string}
};
// #docregion setup
beforeEach(() => {
// stub UserService for test purposes
// #docregion user-service-stub
userServiceStub = {
isLoggedIn: true,
user: { name: 'Test User'}
};
// #enddocregion user-service-stub
// #docregion config-test-module
TestBed.configureTestingModule({
declarations: [ WelcomeComponent ],
// #enddocregion setup
// providers: [ UserService ] // NO! Don't provide the real service!
// Provide a test-double instead
// #docregion setup
providers: [ {provide: UserService, useValue: userServiceStub } ]
});
// #enddocregion config-test-module
fixture = TestBed.createComponent(WelcomeComponent);
comp = fixture.componentInstance;
// #enddocregion setup
// #docregion injected-service
// UserService actually injected into the component
userService = fixture.debugElement.injector.get(UserService);
// #enddocregion injected-service
componentUserService = userService;
// #docregion setup
// #docregion inject-from-testbed
// UserService from the root injector
userService = TestBed.get(UserService);
// #enddocregion inject-from-testbed
// get the "welcome" element by CSS selector (e.g., by class name)
de = fixture.debugElement.query(By.css('.welcome'));
el = de.nativeElement;
});
// #enddocregion setup
// #docregion tests
it('should welcome the user', () => {
fixture.detectChanges();
const content = el.textContent;
expect(content).toContain('Welcome', '"Welcome ..."');
expect(content).toContain('Test User', 'expected name');
});
it('should welcome "Bubba"', () => {
userService.user.name = 'Bubba'; // welcome message hasn't been shown yet
fixture.detectChanges();
expect(el.textContent).toContain('Bubba');
});
it('should request login if not logged in', () => {
userService.isLoggedIn = false; // welcome message hasn't been shown yet
fixture.detectChanges();
const content = el.textContent;
expect(content).not.toContain('Welcome', 'not welcomed');
expect(content).toMatch(/log in/i, '"log in"');
});
// #enddocregion tests
// #docregion inject-it
it('should inject the component\'s UserService instance',
inject([UserService], (service: UserService) => {
expect(service).toBe(componentUserService);
}));
// #enddocregion inject-it
it('TestBed and Component UserService should be the same', () => {
expect(userService === componentUserService).toBe(true);
});
// #docregion stub-not-injected
it('stub object and injected UserService should not be the same', () => {
expect(userServiceStub === userService).toBe(false);
// Changing the stub object has no effect on the injected service
userServiceStub.isLoggedIn = false;
expect(userService.isLoggedIn).toBe(true);
});
// #enddocregion stub-not-injected
});