在角度2中运行jasmine规范时出现此错误:
无法读取null jasmine angular 2的属性'injector'
堆栈跟踪:
TypeError: Cannot read property 'injector' of null
at TestBed._createCompilerAndModule (http://localhost:3002/node_modules/@angular/core/bundles/core-testing.umd.js:834:48)
at TestBed._initIfNeeded (http://localhost:3002/node_modules/@angular/core/bundles/core-testing.umd.js:800:43)
at TestBed.createComponent (http://localhost:3002/node_modules/@angular/core/bundles/core-testing.umd.js:884:18)
at Function.TestBed.createComponent (http://localhost:3002/node_modules/@angular/core/bundles/core-testing.umd.js:714:33)
at Object.eval (http://localhost:3002/js/app/landing-page/subcomponents/middle-row.component.spec.js:29:49)
at ZoneDelegate.invoke (http://localhost:3002/node_modules/zone.js/dist/zone.js:232:26)
at ProxyZoneSpec.onInvoke (http://localhost:3002/node_modules/zone.js/dist/proxy.js:79:39)
at ZoneDelegate.invoke (http://localhost:3002/node_modules/zone.js/dist/zone.js:231:32)
at Zone.run (http://localhost:3002/node_modules/zone.js/dist/zone.js:114:43)
at Object.eval (http://localhost:3002/node_modules/zone.js/dist/jasmine-patch.js:102:34)
我已从the official angular 2 testing docs复制此规范:
let comp: BannerComponent;
let fixture: ComponentFixture<BannerComponent>;
let de: DebugElement;
let el: HTMLElement;
describe('BannerComponent', () => {
beforeEach(() => {
TestBed.configureTestingModule({
declarations: [ BannerComponent ], // declare the test component
});
fixture = TestBed.createComponent(BannerComponent);
comp = fixture.componentInstance; // BannerComponent test instance
// query for the title <h1> by CSS element selector
de = fixture.debugElement.query(By.css('h1'));
el = de.nativeElement;
});
});
并使用我的代码轻微调整它:
import 'zone.js/dist/long-stack-trace-zone.js';
import 'zone.js/dist/async-test.js';
import 'zone.js/dist/fake-async-test.js';
import 'zone.js/dist/sync-test.js';
import 'zone.js/dist/proxy.js';
import 'zone.js/dist/jasmine-patch.js';
import { ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { MiddleRowComponent } from './middle-row.component';
let comp: MiddleRowComponent;
let fixture: ComponentFixture<MiddleRowComponent>;
let de: DebugElement;
let el: HTMLElement;
describe('MiddleRowComponent', () => {
beforeEach(() => {
TestBed.configureTestingModule({
declarations: [MiddleRowComponent], // declare the test component
});
fixture = TestBed.createComponent(MiddleRowComponent);
comp = fixture.componentInstance; // MiddleRowComponent test instance
// query for the title <h1> by CSS element selector
de = fixture.debugElement.query(By.css('h1'));
el = de.nativeElement;
});
it('should display original title', () => {
fixture.detectChanges();
expect(el.textContent).toContain(comp.word);
});
it('should display a different test title', () => {
comp.word = 'Test Title';
fixture.detectChanges();
expect(el.textContent).toContain('Test Title');
});
});
为什么我收到错误?没有注入关键字,但我想TestBed
可能会在幕后使用它。
答案 0 :(得分:8)
在某些时候(在执行任何测试之前),您需要通过调用TestBed.initTestEnvironment(...)
来初始化测试环境。
您通常会在karma-test-shim文件中看到这一点,如angular quickstart(测试文档中的快速入门)所示。但是,如果您不使用此技术,则需要在测试文件中执行此操作。但initTestEnvironment
只应调用一次,因此您还需要在每个测试文件中重置它
import { BrowserDynamicTestingModule,
platformBrowserDynamicTesting } from '@angular/platform-browser-dynamic/testing';
beforeAll(() => {
TestBed.resetTestEnvironment();
TestBed.initTestEnvironment(BrowserDynamicTestingModule,
platformBrowserDynamicTesting());
});