角13 TestBed不注入拦截器
我有一个具有自定义HTTP客户端和拦截器的角13应用程序，我想对其进行单元测试。
base-url.interceptor.ts
import { Inject, Injectable } from '@angular/core';
import { HttpRequest, HttpHandler, HttpEvent, HttpInterceptor } from '@angular/common/http';
import { Observable } from 'rxjs';
export const BASE_API_URL = 'BASE_API_URL';
@Injectable()
export class BaseUrlInterceptor implements HttpInterceptor {
constructor(@Inject(BASE_API_URL) private baseUrl: string) {}
intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
const apiRequest = request.clone({ url: `${this.baseUrl}${request.url}` });
return next.handle(apiRequest);
}
}base-url.interceptor.spec.ts
import { TestBed } from '@angular/core/testing';
import { ApiHttpService, API_HTTP_INTERCEPTORS } from '../api-http.service';
import { BaseUrlInterceptor, BASE_API_URL } from './base-url.interceptor';
describe('BaseUrlInterceptor', () => {
let interceptor: BaseUrlInterceptor;
beforeEach(() => {
TestBed.configureTestingModule({
imports: [],
providers: [
ApiHttpService,
{ provide: BASE_API_URL, value: 'http://example.com' },
{ provide: API_HTTP_INTERCEPTORS, useClass: BaseUrlInterceptor, multi: true }
]
});
interceptor = TestBed.inject(BaseUrlInterceptor);
});
it('should be created', () => {
expect(interceptor).toBeTruthy();
});
});不幸的是，TestBed.inject(BaseUrlInterceptor)未能注入拦截器的实例。interceptor总是undefined。如果我通过手动创建实例new BaseUrlInterceptor('http://example.com');来解决这个问题，它可以工作，但是其他拦截器还有更多的依赖项，我想在这里使用。
如何配置TestBed，以便它能够成功地创建BaseUrlInterceptor实例
我创建了一个最小的CodeSandbox，它再现了问题：https://codesandbox.io/s/snowy-dust-t964no?file=/src/app/base-url.interceptor.spec.ts
此外，当我运行错误测试时，我会得到这个错误消息：
Chrome Headless 98.0.4758.102 (Linux x86_64) BaseUrlInterceptor should be created FAILED
Error: NG0204: unreachable
error properties: Object({ code: 204 })
Error: NG0204: unreachable
at injectableDefOrInjectorDefFactory (node_modules/@angular/core/fesm2015/core.mjs:11494:1)
at providerToFactory (node_modules/@angular/core/fesm2015/core.mjs:11556:1)
at providerToRecord (node_modules/@angular/core/fesm2015/core.mjs:11521:1)
at R3Injector.processProvider (node_modules/@angular/core/fesm2015/core.mjs:11424:1)
at node_modules/@angular/core/fesm2015/core.mjs:11410:1
at node_modules/@angular/core/fesm2015/core.mjs:4162:1
at Array.forEach (<anonymous>)
at deepForEach (node_modules/@angular/core/fesm2015/core.mjs:4162:1)
at R3Injector.processInjectorType (node_modules/@angular/core/fesm2015/core.mjs:11410:1)
at node_modules/@angular/core/fesm2015/core.mjs:11213:1
Error: Expected undefined to be truthy.
at <Jasmine>
at UserContext.<anonymous> (projects/frontend/src/app/core/http/interceptors/base-url.interceptor.spec.ts:21:25)
at ZoneDelegate.invoke (node_modules/zone.js/fesm2015/zone.js:372:1)
at ProxyZoneSpec.onInvoke (node_modules/zone.js/fesm2015/zone-testing.js:287:1)
Chrome Headless 98.0.4758.102 (Linux x86_64): Executed 1 of 1 (1 FAILED) (0.072 secs / 0.056 secs)
TOTAL: 1 FAILED, 0 SUCCESS回答 1
Stack Overflow用户
发布于 2022-02-24 13:15:46
您获得Error: NG0204: unreachable是因为当您定义BASE_API_URL的提供程序时，您使用的是属性value，而它应该是useValue。
{ provide: BASE_API_URL, useValue: 'http://example.com' },无论如何，即使您修复了这个问题，您也会得到一个NullInjectorError，因为您没有定义一个使用BaseUrlInterceptor类作为InjectionToken的提供程序。您将使用该类作为API_HTTP_INTERCEPTORS令牌的提供程序之一。
在单元测试拦截器的上下文中，您应该摆脱ApiHttpService，只关注拦截器类。
你有两个选择：
手动实例化类
beforeEach(() => {
interceptor = new BaseUrlInterceptor('http://example.com');
});或使用拦截器类作为测试床中的提供程序。
beforeEach(() => {
TestBed.configureTestingModule({
imports: [],
providers: [
{ provide: BASE_API_URL, useValue: 'http://example.com' },
BaseUrlInterceptor,
],
});
interceptor = TestBed.inject(BaseUrlInterceptor);
});干杯
https://stackoverflow.com/questions/71251261
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