TESTBED.inject 无法读取 null

如何解决TESTBED.inject 无法读取 null

我想测试一个将脚本注入到 Angular 组件或页面文档中的 Angular 服务

这是我的服务：

import { Injectable,Inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';

@Injectable()
export class NgxToolsLoadService {
  constructor(@Inject(DOCUMENT) private document: any) {}

  load(
    src: string,): void {

 let el = this.document.createElement('script');
 el.src=sec;
 this.document.getElementsByTagName('head')[0].appendChild(el);
    
  }
}

这是我的 jest.config

module.exports = {
  preset: "ts-jest",testEnvironment: "node",onlyChanged: true,collectCoverage: false,moduleDirectories: ["node_modules","types"],modulefileExtensions: ["ts","tsx","js","jsx","json","node"],transform: {
    "^.+\\.(t|j)sx?$": "ts-jest",},};

我尝试将 testEnvironment 更改为 jsdom，但出现错误：Exceeded timeout of 5000 ms for a test 并且此代码没有帮助

jest.setTimeout(100000);
jest.usefaketimers('legacy');

现在我正在使用 testEnvironment: node

然而，这些是我的测试试验

// myservice.service.spec.ts

import { test,expect,afterall,beforeEach,jest } from '@jest/globals';
import { Testbed } from '@angular/core/testing';
import { MyService} from './myservice.service';
import { DOCUMENT } from '@angular/common';

let service: MyService;

beforeEach(async () => {
  await Testbed.configureTestingModule({
    providers: [MyService,{ provide: Document,useExisting: DOCUMENT }],});
  service= Testbed.inject(MyService);
});

test('service should be created',() => {
  expect(ngxToolsLoadService).toBeTruthy();
});

测试失败，无法创建服务 我收到了这个错误

ReferenceError: StaticInjectorError(DynamicTestModule)[NgxToolsLoadService -> InjectionToken DocumentToken]: 
      StaticInjectorError(Platform: core)[NgxToolsLoadService -> InjectionToken DocumentToken]: 
        document is not defined

解决方法

通过在 jest.config.js 文件中使用 jest-preset-angular 而不是 ts-jest 解决