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angular - 用 Jasmine 模拟 Angular 9 服务

转载 作者:行者123 更新时间:2023-12-04 11:01:14 28 4
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使用 Angular 7,我可以模拟我的 SearchService通过创建几个类来使用 Jasmine。第一个是 helper.ts具有可以扩展的类的文件。

/// <reference path="../../../../../node_modules/@types/jasmine/index.d.ts"‌​/>

export interface GuinessCompatibleSpy extends jasmine.Spy {
/** By chaining the spy with and.returnValue, all calls to the function will return a specific
* value. */
andReturn(val: any): void;
/** By chaining the spy with and.callFake, all calls to the spy will delegate to the supplied
* function. */
andCallFake(fn: Function): GuinessCompatibleSpy;
/** removes all recorded calls */
reset();
}

export class SpyObject {
static stub(object = null, config = null, overrides = null) {
if (!(object instanceof SpyObject)) {
overrides = config;
config = object;
object = new SpyObject();
}

const m = {};
Object.keys(config).forEach((key) => m[key] = config[key]);
Object.keys(overrides).forEach((key) => m[key] = overrides[key]);
for (const key in m) {
object.spy(key).andReturn(m[key]);
}
return object;
}

constructor(type = null) {
if (type) {
for (const prop in type.prototype) {
let m = null;
try {
m = type.prototype[prop];
} catch (e) {
// As we are creating spys for abstract classes,
// these classes might have getters that throw when they are accessed.
// As we are only auto creating spys for methods, this
// should not matter.
}
if (typeof m === 'function') {
this.spy(prop);
}
}
}
}

spy(name) {
if (!this[name]) {
this[name] = this._createGuinnessCompatibleSpy(name);
}
return this[name];
}

prop(name, value) { this[name] = value; }

/** @internal */
_createGuinnessCompatibleSpy(name): GuinessCompatibleSpy {
const newSpy: GuinessCompatibleSpy = <any>jasmine.createSpy(name);
newSpy.andCallFake = <any>newSpy.and.callFake;
newSpy.andReturn = <any>newSpy.and.returnValue;
newSpy.reset = <any>newSpy.calls.reset;
// revisit return null here (previously needed for rtts_assert).
newSpy.and.returnValue(null);
return newSpy;
}
}

这是 search.service.ts我正在尝试测试:
@Injectable({
providedIn: 'root'
})
export class SearchService {

constructor(private http: HttpClient) { }

getAll() {
return this.http.get('assets/data/people.json');
}

search(q: string): Observable<any> {
// implementation
}

get(id: number) {
// implementation
}

save(person: Person) {
// implementation
}
}

这是我的 search.service.mock.ts :
import { SpyObject } from './helper';
import { SearchService } from '../search.service';
import Spy = jasmine.Spy;

export class MockSearchService extends SpyObject {
getAllSpy: Spy;
getByIdSpy: Spy;
searchSpy: Spy;
saveSpy: Spy;
fakeResponse: any;

constructor() {
super(SearchService);

this.fakeResponse = null;
this.getAllSpy = this.spy('getAll').andReturn(this);
this.getByIdSpy = this.spy('get').andReturn(this);
this.searchSpy = this.spy('search').andReturn(this);
this.saveSpy = this.spy('save').andReturn(this);
}

subscribe(callback: any) {
callback(this.fakeResponse);
}

setResponse(json: any): void {
this.fakeResponse = json;
}
}

然后我在测试中 mock 它。
import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { SearchComponent } from './search.component';
import { MockSearchService } from '../shared/search/mocks/search.service';
import { MockActivatedRoute, MockRouter } from '../shared/search/mocks/routes';
import { SearchService } from '../shared';
import { ActivatedRoute, Router } from '@angular/router';
import { RouterTestingModule } from '@angular/router/testing';
import { FormsModule } from '@angular/forms';

describe('SearchComponent', () => {
let component: SearchComponent;
let fixture: ComponentFixture<SearchComponent>;
let mockSearchService: MockSearchService;
let mockActivatedRoute: MockActivatedRoute;

beforeEach(async(() => {
mockSearchService = new MockSearchService();
mockActivatedRoute = new MockActivatedRoute({'term': 'peyton'});

TestBed.configureTestingModule({
declarations: [ SearchComponent ],
providers: [
{provide: SearchService, useValue: mockSearchService},
{provide: ActivatedRoute, useValue: mockActivatedRoute}
],
imports: [FormsModule, RouterTestingModule]
}).compileComponents();
}));

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

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

这适用于 Angular 7。但是,当我尝试使用 Angular 9 时,我必须删除 // <reference path="..."/>顶部 helper.ts修复一些编译器错误。
ERROR in node_modules/@types/jasmine/index.d.ts:25:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: ImplementationCallback, Func, Constructor, ExpectedRecursive, Expected, SpyObjMethodNames, CustomEqualityTester, CustomMatcherFactory, ExpectationFailed, SpecFunction, SpyObj, jasmine

25 type ImplementationCallback = jasmine.ImplementationCallback;
~~~~

然后我得到两个错误:
Chrome 78.0.3904 (Mac OS X 10.15.1) SearchComponent should create FAILED
Failed: this.getSpy is not a function
at <Jasmine>

和:
NullInjectorError: R3InjectorError(DynamicTestModule)[SearchService -> HttpClient -> HttpClient]:
NullInjectorError: No provider for HttpClient!
error properties: Object({ ngTempTokenPath: null, ngTokenPath: [ 'SearchService', 'HttpClient', 'HttpClient' ] })

知道为什么这适用于 Angular 7 而不适用于 Angular 9 吗?

适用于 Angular 7 的应用程序位于 GitHub 上 https://github.com/mraible/ng-demo .

最佳答案

我决定摆脱 helper.ts 会更容易并模拟服务返回的内容。我也改成导入HttpClientTestingModule所以服务可以被实例化,即使它的 HttpClient从不使用。这是我的 search.component.spec.ts在这次重构之后:

import { async, ComponentFixture, TestBed } from '@angular/core/testing';

import { SearchComponent } from './search.component';
import { MockActivatedRoute } from '../shared/search/mocks/routes';
import { SearchService } from '../shared';
import { ActivatedRoute } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { RouterTestingModule } from '@angular/router/testing';
import { of } from 'rxjs';
import { HttpClientTestingModule } from '@angular/common/http/testing';

describe('SearchComponent', () => {
let component: SearchComponent;
let fixture: ComponentFixture<SearchComponent>;
let mockActivatedRoute: MockActivatedRoute;
let mockSearchService: SearchService;

beforeEach(async(() => {
mockActivatedRoute = new MockActivatedRoute({term: 'nikola'});

TestBed.configureTestingModule({
declarations: [SearchComponent],
providers: [
{provide: ActivatedRoute, useValue: mockActivatedRoute}
],
imports: [FormsModule, RouterTestingModule, HttpClientTestingModule]
}).compileComponents();
}));

beforeEach(() => {
// mock response
mockSearchService = TestBed.inject(SearchService);
mockSearchService.search = jasmine.createSpy().and.returnValue(of([]));

// initialize component
fixture = TestBed.createComponent(SearchComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});

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

it('should search when a term is set and search() is called', () => {
component = fixture.debugElement.componentInstance;
component.query = 'J';
component.search();
expect(mockSearchService.search).toHaveBeenCalledWith('J');
});

it('should search automatically when a term is on the URL', () => {
fixture.detectChanges();
expect(mockSearchService.search).toHaveBeenCalledWith('nikola');
});
});

对于另一个测试,我做了类似的事情,从服务返回预期的数据。
import { EditComponent } from './edit.component';
import { TestBed } from '@angular/core/testing';
import { Address, Person, SearchService } from '../shared';
import { MockRouter, MockActivatedRoute } from '../shared/search/mocks/routes';
import { ActivatedRoute, Router } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { of } from 'rxjs';
import { HttpClientTestingModule } from '@angular/common/http/testing';

describe('EditComponent', () => {
let mockSearchService: SearchService;
let mockActivatedRoute: MockActivatedRoute;
let mockRouter: MockRouter;

beforeEach(() => {
mockActivatedRoute = new MockActivatedRoute({id: 1});
mockRouter = new MockRouter();

TestBed.configureTestingModule({
declarations: [EditComponent],
providers: [
{provide: ActivatedRoute, useValue: mockActivatedRoute},
{provide: Router, useValue: mockRouter}
],
imports: [FormsModule, HttpClientTestingModule]
}).compileComponents();

mockSearchService = TestBed.inject(SearchService);
});

it('should fetch a single record', () => {
const fixture = TestBed.createComponent(EditComponent);

const person = new Person({id: 1, name: 'Gary Harris'});
person.address = new Address({city: 'Denver'});

// mock response
spyOn(mockSearchService, 'get').and.returnValue(of(person));

// initialize component
fixture.detectChanges();

// verify service was called
expect(mockSearchService.get).toHaveBeenCalledWith(1);

// verify data was set on component when initialized
const editComponent = fixture.debugElement.componentInstance;
expect(editComponent.editAddress.city).toBe('Denver');

// verify HTML renders as expected
const compiled = fixture.debugElement.nativeElement;
expect(compiled.querySelector('h3').innerHTML).toBe('Gary Harris');
});
});

关于angular - 用 Jasmine 模拟 Angular 9 服务,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58782024/

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