Generating unit tests for an existing Angular2 application using Jasmine Karma can be a crucial step in ensuring the

I recently joined a development team working on an Angular2 application that requires all unit tests to be written using the Jasmine framework. I'm curious if there is a tool available that can automatically generate spec files for each class, providing a starting point with test cases based on methods and attributes like *ng-If in the templates. Below is an example of the component a.component.js

import { Component, Input, Output, Inject, OnChanges, EventEmitter, OnInit } from '@angular/core';
import {Http} from '@angular/http';


@Component({
    selector: 'a-component',
    template : `
    <div *ng-If="model">
       <a-child-component [model]="model">
       </a-child-component>
    </div>`
})

export class AComponent implements OnInit {
    @Input() anInput;
    ngOnInit() {        
        if(this.anInput){
            this.model = anInput;
        }
    }
    constructor(@Inject(Http) http){
        this.restAPI = http;    
    }

    methodOne(arg1,arg2){
        //do something
    }

    methodTwo(arg1,arg2){
        //do something
    }

    //...
}

This would then generate a corresponding spec file: a.componenet.spec.js

import { beforeEach,beforeEachProviders,describe,expect,it,injectAsync } from 'angular2/testing';
import { setBaseTestProviders } from 'angular2/testing';
import { TEST_BROWSER_PLATFORM_PROVIDERS,TEST_BROWSER_APPLICATION_PROVIDERS } from 'angular2/platform/testing/browser';
setBaseTestProviders(TEST_BROWSER_PLATFORM_PROVIDERS, TEST_BROWSER_APPLICATION_PROVIDERS);
import { Component, Input, Output, Inject, OnChanges, EventEmitter, OnInit } from '@angular/core';
import { ComponentFixture, TestBed, inject } from '@angular/core/testing';
import { MockComponent } from 'ng2-mock-component';
import { async } from '@angular/core/testing';
import { Http } from '@angular/http';
import { HttpMock } from '../mocks/http.mock';
import { AComponent } from './a.component';

let model = {"propOne":[],"propTwo":"valueTwo"};

describe('AComponent', () => {
  let fixture;

  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [
            AComponent,
            MockComponent({ 
                selector: 'a-child-component',
                template:'Hello Dad!'
                ,inputs: ['model']
            })
       ],
        providers: [{ provide: Http, useClass: HttpMock }]
    });
    fixture = TestBed.createComponent(AComponent);
    fixture.componentInstance.anInput= model;    
  });

  it('should create the component',() => {
    //
  });
  it('should test methodOne',() => {
    //
  });
  it('should test methodTwo',() => {
    //
  });
  it('should generate the child component when model is populated',() => {
    //
  });
)

Answer №1

It has been some time since I initially posted this inquiry. I've crafted a visual Code extension to aid in this task, and I'm excited to share it with you.

The purpose of this extension goes beyond simply creating the spec file; it also automates the generation of boilerplate code for all necessary test cases. Additionally, it sets up Mocks and injections to accelerate your progress.

One notable feature is the inclusion of a test case that will detect any missing tests. Feel free to modify or remove it if it doesn't align with your requirements.

This was designed for an Angular2 ES6 project, but feel free to adapt it for TypeScript:

Answer №2

If you're looking for a comprehensive visual studio extension, check out Simon test! You can access it through the following link: https://marketplace.visualstudio.com/items?itemName=SimonTest.simontest. This extension allows you to easily generate unit tests along with boilerplate code. Plus, you get a 30-day trial period to explore all its features.

Answer №3

After thorough testing with ngx-spec using Jasmine/Karma, I successfully got it up and running:

Create .spec files for existing components in Angular CLI


On the other hand, my experience with ngentest and Jasmine/Karma was not as smooth—it failed to work for me.

For more insights on this issue, you can check out the following resources:

Encountering error TS1127 when running Karma tests in Angular 7

Additionally, there is a related Github problem that may shed some light on the matter:

Github issue: https://github.com/allenhwkim/ngentest/issues/17

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