如何编写angular2的登录组件测试（单元测试）

Question

This is login.component.ts




    import { Component, OnInit } from '@angular/core';
    import { Router, ActivatedRoute } from '@angular/router';
    import { FormBuilder, FormGroup, Validators } from '@angular/forms';
    import { CommonModule } from  '@angular/common';


    import { LoginUser } from './loginUser.model'
    import { UserService } from './user.service';
    import { LoaderService } from '../shared/loader.service';

    import 'rxjs/add/operator/toPromise';

    @Component({
        templateUrl: './login.component.html'
    })
    export class LoginComponent implements OnInit {
        errorMessage: string;
        loginForm: FormGroup;
        loginObj = new LoginUser();

        constructor(private userService: UserService, private loaderService: LoaderService, private router: Router, fb: FormBuilder) {
            this.loginForm = fb.group({
                userName: [null, Validators.required],
                password: [null, Validators.required]
            })
            console.log(this.loginForm);
        }

    test() : void{
        console.log("This is a test");
    }
        login(loginObjValue: any): void {
            if (loginObjValue.userName == null || loginObjValue.password == null) {
                console.log('error');
            } else {
                this.loginObj.userName = loginObjValue.userName;
                this.loginObj.password = loginObjValue.password;
                this.loaderService.displayLoader(true);

                this.userService.login(this.loginObj)
                    .then((res) => {
                        console.log("data", res);
                        console.log("$localStorage.currentUser", localStorage);
                        let link = ['customercare/customer-ticket'];
                        this.loaderService.displayLoader(false);

                        this.router.navigate(link);
                    })
                    .catch(error => this.handleError(error));
            }
        }

        private handleError(error: any): Promise<any> {
            this.loaderService.displayLoader(false);

            if (error._body) {
                this.errorMessage = JSON.parse(error._body).error_description;
            }

            console.log('An error occurred', error);
            return Promise.reject(error.message || error);
        }

        ngOnInit(): void {


        }
    }





    @Component({
        templateUrl: './login.component.html'
    })
    export class LoginComponent implements OnInit {
        errorMessage: string;
        loginForm: FormGroup;
        loginObj = new LoginUser();

        constructor(private userService: UserService, private loaderService: LoaderService, private router: Router, fb: FormBuilder) {
            this.loginForm = fb.group({
                userName: [null, Validators.required],
                password: [null, Validators.required]
            })
            console.log(this.loginForm);
        }


        login(loginObjValue: any): void {
            if (loginObjValue.userName == null || loginObjValue.password == null) {
                console.log('error');
            } else {
                this.loginObj.userName = loginObjValue.userName;
                this.loginObj.password = loginObjValue.password;
                this.loaderService.displayLoader(true);

                this.userService.login(this.loginObj)
                    .then((res) => {
                        console.log("data", res);
                        console.log("$localStorage.currentUser", localStorage);
                        let link = ['customercare/customer-ticket'];
                        this.loaderService.displayLoader(false);

                        this.router.navigate(link);
                    })
                    .catch(error => this.handleError(error));
            }
        }


    }

  

userservice.ts的部分代码。请参考此代码。部分代码   userservice.ts。请参考此代码。部分代码   userservice.ts。请参考此代码。部分代码   userservice.ts。请参考此代码。部分代码   userservice.ts。请参阅此代码。

    import { Component, OnInit } from '@angular/core';
    import { Router, ActivatedRoute } from '@angular/router';
    import { FormBuilder, FormGroup, Validators } from '@angular/forms';
    import { CommonModule } from  '@angular/common';


    import { LoginUser } from './loginUser.model'
    import { UserService } from './user.service';
    import { LoaderService } from '../shared/loader.service';

    import 'rxjs/add/operator/toPromise';

    @Component({
        templateUrl: './login.component.html'
    })
    export class LoginComponent implements OnInit {
        errorMessage: string;
        loginForm: FormGroup;
        loginObj = new LoginUser();

        constructor(private userService: UserService, private loaderService: LoaderService, private router: Router, fb: FormBuilder) {
            this.loginForm = fb.group({
                userName: [null, Validators.required],
                password: [null, Validators.required]
            })
            console.log(this.loginForm);
        }

    test() : void{
        console.log("This is a test");
    }
        login(loginObjValue: any): void {
            if (loginObjValue.userName == null || loginObjValue.password == null) {
                console.log('error');
            } else {
                this.loginObj.userName = loginObjValue.userName;
                this.loginObj.password = loginObjValue.password;
                this.loaderService.displayLoader(true);

                this.userService.login(this.loginObj)
                    .then((res) => {
                        console.log("data", res);
                        console.log("$localStorage.currentUser", localStorage);
                        let link = ['customercare/customer-ticket'];
                        this.loaderService.displayLoader(false);

                        this.router.navigate(link);
                    })
                    .catch(error => this.handleError(error));
            }
        }

        private handleError(error: any): Promise<any> {
            this.loaderService.displayLoader(false);

            if (error._body) {
                this.errorMessage = JSON.parse(error._body).error_description;
            }

            console.log('An error occurred', error);
            return Promise.reject(error.message || error);
        }

        ngOnInit(): void {


        }
    }

我写的很远：我无法调用登录功能。请指导我。

@Injectable()
export class UserService {
    private URL = "";

    constructor(private http: Http) { }

    login(loginObj: LoginUser) {

        let body = 'userName=' + loginObj.userName + '&password=' + loginObj.password + '&grant_type=password';

        let headers = new Headers();
        headers.append('Content-Type', 'application/x-www-form-urlencoded');

        return this.http.post(this.URL + '/token', body, { headers: headers })
            .toPromise()
            .then((res: Response) => {
                let data = res.json();
                if (data && data.access_token) {
                    localStorage.setItem('currentUser', JSON.stringify(data));
                }
                return data;
            })
    }

}

Answer 1

所以我不确定错误是什么，但我看到的最重要的事情可能是在创建组件之前没有调用compileComponents。

beforeEach(async(() => {
      TestBed.configureTestingModule({
        declarations: [ LoginComponent ],
        providers: [
            { provide: UserService, useValue: UserService },
                   ]
      }).compileComponents();
}); <--- also looked to be missing

这只是我的建议，我不在机器附近测试你的方式是否可行，但我也会在每个之前获取一个对fixture的引用，并使用它来在测试中创建你的组件。和上面一样但是：

beforeEach(async(() => {
      TestBed.configureTestingModule({
        declarations: [ LoginComponent ],
        providers: [
            { provide: UserService, useValue: UserService },
                   ]
      }).compileComponents();
}); 

beforeEach(async(() => {
      // components are now compiled
      fixture = TestBed.createComponent(LoginComponent);
}); 

主要在您已经创建了对它的引用之前。您尝试在测试中重新创建该引用，但您可以在beforeEach中分配它并使用它。

此外，你的测试并没有真正做任何我能看到触发任何事情的事情。如果这是您的目标，您可以验证它是否存在。

 it('should call the login method when the component does something', 
        inject([UserService], ((userService: UserService) => {
          spyOn(userService, 'login');
          let component = fixture.componentInstance;
          component.doSomething();
          expect(userService.login).toHaveBeenCalled();
          });
 }));

由于您只测试函数被调用，因此实际上不需要在异步中包装任何内容。您不是在等待DOM中的响应或其他任何事情，只是在调用组件自己的login（）方法时，确实验证了服务上的login（）方法。如果有任何疑问，你可以投入一个无害的fixture.detectChanges（），但我相信，如果你在模板中改变某些东西，通常也会确保元素已经传播回来。

老实说，即使是那种纯粹的单元测试。您可以为UserService编写其他单元测试。如果你想验证LoginComponent的某些方面，我会编写测试断言，一旦LoginComponent登录就应该变异或者是什么（可能是DOM中的文本已经改变等）。或者，如果您只是测试业务逻辑，则可以拦截登录调用以返回true或false并验证doSomething（）是否正确响应。