Question

我试图为一个接受对象作为参数的Pipe编写单元测试。此对象是从模拟服务创建的。

单元测试管道时是否可以使用模拟服务？我是否必须在测试中包含使用管道的组件？

PIPE - 此管道基本上接受一个对象和一组参数。基于参数，它操纵对象参数并返回它。

@Pipe({
  name: 'myPipe'
})
export class MyPipe implements PipeTransform {

  transform(myData: models.MyInfo, args: string[]): string { //stuff here }
}

MOCK SERVICE - 模拟服务查询在管道参数中使用的对象数组。

@Injectable()
export class MockMyService {
getMyInfo(){
//logic
}

在组件中使用管道的示例 - 以下是如何使用它的示例

this.xObj = this.realService.GetInfo();     
this.myList = this.myPipe.transform(this.xObj[0], ['a', 'b', 'c',]).split(',');

我试过的单位测试 - 我尝试了几件事。下面的代码显示了我如何尝试耦合Component和Pipe，以及尝试测试没有组件的管道。

//core dependencies
import { ComponentFixture, TestBed }  from "@angular/core/testing";
import { NO_ERRORS_SCHEMA }           from '@angular/core';
import { By }                         from '@angular/platform-browser';
import { DebugElement }               from '@angular/core';
import { RouterTestingModule }        from '@angular/router/testing';
import { HttpModule }                 from '@angular/http';
import { DatePipe }                   from '@angular/common';

//pipe, component being tested
import { MyPipe } from './path to pipe';
import { ComponentThatUsesPipe } from '../path to the component';

//models / other
import { MOCKEDOBJECT } from '..path'

//services
import { MockMyService } from '..path to service';
import { RealService } from '..path to real service';

describe('myPipe', () => {
  let pipe = new MyPipe();
  let component: ComponentThatUsesPipe ;

  var myDetailsArray: models.ObjDetails[] = MOCKEDOBJECT ;
  var myDetails: models.ObjDetails;
  var myList: string[] = [];


  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [ComponentThatUsesPipe, MyPipe],
      providers: [{provide: RealService, useClass: MockMyService}]
    });
    component = TestBed.createComponent(ComponentThatUsesPipe ).componentInstance;
  });

  this.myList = pipe.transform(this.myDetails.m[0], ['a','b',1,2,3]);

  it('test1', () => {
     expect(this.myList.findIndex(s => s.trim() === 'Med') > -1).toBe(true);
  });
});

我的测试返回错误“无法读取m＆＃39;的属性”。

编辑 - 能够根据＆＃39; estus＆＃39;的建议解决。以下评论

describe('myPipe', () => {
  let pipe = new myPipe();
  let myDetailsArray: models.ObjDetails[] = MOCKEDOBJECT;
  let myDetails: models.ObjDetails = myDetailsArray[0];
  let hasA: boolean = false;
  let hasB: boolean = false;
  let hasC: boolean = false;
  let myList: string[] = [];

  this.myList = pipe.transform(myDetails.member[0],[stuff here]).split(',');
  this.hasA = (this.myList.findIndex(s => s.trim() === 'M') > -1);
  this.hasB = (this.myList.findIndex(s => s.trim() === 'P') > -1);
  this.hasC = (this.myList.findIndex(s => s.trim() === 'D') > -1);

  it('test myPipe hasA', () => {
     expect(this.hasA).toBe(true);
  });

  it('test myPipe hasB', () => {
     expect(this.hasB).toBe(true);
  });

  it('test myPipe hasC', () => {
     expect(this.hasC).toBe(false);
  });

});

angular2如何单元测试需要模拟服务的管道

0 个答案: