Angular組件（帶指令）測試

Question

我有一個要測試的組件。 測試失敗並顯示消息

AdminPanelComponent > 應該創建

TypeError：無法讀取未定義的屬性“角色”

錯誤屬性： Object({ ngDebugContext: DebugContext_({ view: Object({ def: Object({ factory: Function, nodeFlags: 50577443, rootNodeFlags: 1, nodeMatchedQueries: 0, flags: 0, 節點: [ Object({ nodeIndex: 0 , parent: null, renderParent: null, bindingIndex: 0, outputIndex: 0, checkIndex: 0, flags: 1, childFlags: 50577443, directChildFlags: 1, childMatchedQueries: 0, matchedQueries: Object({ }), matchedQueryIds: 0, references ：對象（{}），ngContentIndex：null，childCount：11，綁定：[]，bindingFlags：0，輸出：[]，元素：對象（{ ns：''，名稱：'div'，attrs：[數組] , template: null, componentProvider: null, componentView: null, componentRendererType: null, publicProviders: null({ }), allProviders: null({ }), handleEvent: Z86408593C34AF77FDD90D F932F8B5261Z }), provider: null, text: null, query: null, ngContent: null }), Object({ nodeIndex: 1, parent: Object({ nodeIndex: 0, parent: null, renderParent: null, bindingIndex: 0, outputIndex: 0, checkIndex: 0, flags: 1, childFlags: 50577443, directChildFlags: 1, chi... at HasRoleDirective.ngOnInit ( http://localhost:9876/_karma_webpack_/src/app/_directives/hasRole.directive。 ts:16:53 ) at checkAndUpdateDirectiveInline ( http://localhost:9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:26276:1 ) at checkAndUpdateNodeInline ( http://localhost:9876/_karma_webpack_/node_modules /@angular/core/fesm2015/core.js:37133:1 ) 在 checkAndUpdateNode ( http://localhost:9876/_karma_web pack_/node_modules/@angular/core/fesm2015/core.js:37072:1 ) 在 debugCheckAndUpdateNode ( http://localhost:9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:38094:36 ) 在debugCheckDirectivesFn ( http://localhost:9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:38037:1 ) at Object.eval [as updateDirectives] (ng:///DynamicTestModule/AdminPanelComponent.ngfactory.js :62:5) at Object.debugUpdateDirectives [as updateDirectives] ( http://localhost:9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:38025:1 ) at checkAndUpdateView ( http://localhost: 9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:37037:1 ) 在 callViewAction ( http://localhost:9876/_karma_webpack_/node_modules/@angular/core/fesm2015/core.js:374031: )

管理面板.component.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-admin-panel',
  templateUrl: './admin-panel.component.html',
  styleUrls: ['./admin-panel.component.css']
})
export class AdminPanelComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

管理面板.component.html

<div class="container mt-5">
  <h2>Admin panel</h2>
  <div class="tab-panel">
    <tabset class="member-tabset">
      <tab heading="User Management" *appHasRole="['Admin']">
        <div class="container">
            <app-user-management></app-user-management>  
        </div>        
      </tab>
      <tab heading="Photo management" *appHasRole="['Admin', 'Moderator']">
        <app-photo-management></app-photo-management>
      </tab>
    </tabset>
  </div>
</div>

hasRole.directive.ts

import { Directive, Input, ViewContainerRef, TemplateRef, OnInit } from '@angular/core';
import { AuthService } from '../_services/auth.service';

@Directive({
  selector: '[appHasRole]'
})
export class HasRoleDirective implements OnInit {
  @Input() appHasRole: string[];
  isVisible = false;

  constructor(private viewContainerRef: ViewContainerRef,
              private templateRef: TemplateRef<any>,
              private authService: AuthService) { }

  ngOnInit() {
    const userRoles = this.authService.decodedToken.role as Array<string>;
    // if no roles clear the viewContainerRef
    if (!userRoles) {
      this.viewContainerRef.clear();
    }

    // if user has role need to render the element
    if (this.authService.roleMatch(this.appHasRole)) {
      if (!this.isVisible) {
        this.isVisible = true;
        this.viewContainerRef.createEmbeddedView(this.templateRef);
      } else {
        this.isVisible = false;
        this.viewContainerRef.clear();
      }
    }
  }
}

無法工作的代碼部分是

const userRoles = this.authService.decodedToken.role as Array<string>;

如何測試這個組件？

Answer 1

測試 angular 應用程序的最佳方法是模擬除您要測試的組件之外的所有內容。

最簡單的方法是使用像ng-mocks這樣的庫。

不過，您需要像那樣存根 AuthService

TestBed.configureTestingModule({
  declarations: [HasRoleDirective, AdminPanelComponent],
  provides: [
    {
      provide: AuthService,
      useValue: {
        decodedToken: {
          role: [], // <- you can put here values for the test
        },
        roleMatch: () => false, // <- or to use a spy here.
      },
    },
  ],
})

在這種情況下，AuthService 將是一個帶有不做任何事情的假方法的存根。