找不到管道“翻译”，Angular2组件测试

Question

我正在使用 angular2 进行组件测试。 在我的 html 模板中，我使用翻译管道。 这是测试代码：

import { ComponentFixture, TestBed ,getTestBed} from '@angular/core/testing';
import { By }              from '@angular/platform-browser';
import { DebugElement }    from '@angular/core';
import { RightComponent } from './right.component';
import {TranslateService} from 'ng2-translate/ng2-translate';
import {Injector} from "@angular/core";
let comp:    RightComponent;
let fixture: ComponentFixture<RightComponent>;
let el:      DebugElement;
let translate: TranslateService;
let injector: Injector;

describe('testComponent', () => {

beforeEach(() => {
TestBed.configureTestingModule({
  declarations: [ RightComponent ]
});

 injector = getTestBed();
 translate = injector.get(TranslateService);
fixture = TestBed.createComponent(RightComponent);

comp = fixture.componentInstance; // BannerComponent test instance

// get title DebugElement by element name
el = fixture.debugElement.query(By.css('h2'));
});
it('should display original title', () => {
fixture.detectChanges(); // trigger data binding
expect(el.nativeElement.textContent).toContain('Liste des droits');
});

});

我收到此错误，翻译管道未知：

Error: Template parse errors:
The pipe 'translate' could not be found ("<h2>[ERROR ->]{{'RIGHT_TITLE' |      translate}}</h2>
<div class="table-responsive">
<table id="rightTableId" clas"): RightComponent@0:4
 The pipe 'translate' could not be found ("
  <table id="rightTableId" class="table table-striped">
     <tr>
         <th>[ERROR ->]{{'NAME_LABEL' | translate}}</th>
     </tr>
     <tr *ngFor="let right of rights">
 "): RightComponent@4:16
  The pipe 'translate' could not be found ("
     </tr>
     <tr *ngFor="let right of rights">
         <td>[ERROR ->]{{right.name | translate}}</td>
     </tr>
 </table>

我们如何解决这个问题？

谢谢。

Answer 1

这是 ng2-translate github.com/ocombe/ng2-translate

您需要使用库模块配置

TestBed

，就像使用实际应用程序配置库一样。查看文档，它显示通过导入模块来配置它

imports: [
  TranslateModule.forRoot()
]

所以你应该在

TestBed

配置中做同样的事情

TestBed.configureTestingModule({
  declarations: [ RightComponent ],
  imports: [TranslateModule.forRoot()]
});

这就是

TestBed.configureTestingModule

的用途：为测试环境配置模块。

Answer 2

与最新的 Angular 4 兼容

ngx-translate

，您需要将其直接实现到要测试的组件中：

import {TranslateHttpLoader} from "@ngx-translate/http-loader";
import {Http, HttpModule} from "@angular/http";
import {
    MissingTranslationHandler,
    TranslateLoader,
    TranslateModule,
    TranslateService
} from "@ngx-translate/core";

...

export function HttpLoaderFactory(http: Http) {
    return new TranslateHttpLoader(http, "./assets/i18n/", ".json");
}

   ...

   imports: [
                TranslateModule.forRoot({
                    loader: {
                        provide: TranslateLoader,
                        useFactory: HttpLoaderFactory,
                        deps: [Http]
                    }
                })
            ],
   ...

   providers: [
                TranslateService
   ...

Answer 3

beforeEach(() => {
        TestBed.configureTestingModule({
          imports: [TranslateModule.forRoot()],
          declarations: [HeaderComponent],
          schemas: [CUSTOM_ELEMENTS_SCHEMA]
        }).compileComponents(); 
  });

所以它也帮助了我！

Answer 4

为了完整性，如果您忘记将测试的组件放入声明中，它也会给出相同的错误：“无法找到管道'...'”

declarations: [ RightComponent ],