小编Pra*_*tra的帖子

我在进行单元测试时正在使用angular 2进行单元测试，这表明错误无法读取未定义的“快照”属性。

ReadMailComponent should create
TypeError: Cannot read property 'snapshot' of undefined
TypeError: Cannot read property 'snapshot' of undefined
    at ReadMailComponent.getCommentId (webpack:///D:/Zool-Projects/mindspark/src/app/modules/my-mindspark/components/read-mail/read-mail.component.ts?:48:27)
    at ReadMailT1Component.ReadMailT2Component.ngOnInit (webpack:///D:/Zool-Projects/mindspark/src/app/shared/components/my-mindspark/read-mail/read-mail-t2/read-mail-t2.component.ts?:34:49)
    at checkAndUpdateDirectiveInline (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:11043:19)
    at checkAndUpdateNodeInline (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:12541:20)
    at checkAndUpdateNode (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:12484:16)
    at debugCheckAndUpdateNode (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:13341:59)
    at debugCheckDirectivesFn (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:13282:13)
    at Object.eval [as updateDirectives] (ng:///DynamicTestModule/ReadMailComponent.ngfactory.js:16:5)
    at Object.debugUpdateDirectives [as updateDirectives] (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:13267:21)
    at checkAndUpdateView (webpack:///D:/Zool-Projects/mindspark/node_modules/@angular/core/@angular/core.es5.js?:12451:14)

这是readmail.component.spec.ts

import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { ReadMailComponent } from './read-mail.component'; …