CODEWITHSUNDEEP
angulartypescript
spring
spring

Reputation: 18517

What are the "spec.ts" files generated by Angular CLI for?

I am using Angular CLI to generate and serve projects. It seems to work well – though for my little learning projects, it produces more than I need – but that's to be expected.

I've noticed that it generates spec.ts for each Angular element in a project (Component, Service, Pipe, etc). I've searched around but have not found an explanation of what these files are for.

Are these build files which are normally hidden when using tsc? I wondered because I wanted to change the name of a poorly named Component I'd created and discovered that the name was also referenced in these spec.ts files.

import {
  beforeEach,
  beforeEachProviders,
  describe,
  expect,
  it,
  inject,
} from '@angular/core/testing';
import { ComponentFixture, TestComponentBuilder } from '@angular/compiler/testing';
import { Component } from '@angular/core';
import { By } from '@angular/platform-browser';
import { PovLevelComponent } from './pov-level.component';

describe('Component: PovLevel', () => {
  let builder: TestComponentBuilder;

  beforeEachProviders(() => [PovLevelComponent]);
  beforeEach(inject([TestComponentBuilder], function (tcb: TestComponentBuilder) {
    builder = tcb;
  }));

  it('should inject the component', inject([PovLevelComponent],
      (component: PovLevelComponent) => {
    expect(component).toBeTruthy();
  }));

  it('should create the component', inject([], () => {
    return builder.createAsync(PovLevelComponentTestController)
      .then((fixture: ComponentFixture<any>) => {
        let query = fixture.debugElement.query(By.directive(PovLevelComponent));
        expect(query).toBeTruthy();
        expect(query.componentInstance).toBeTruthy();
      });
  }));
});

@Component({
  selector: 'test',
  template: `
    <app-pov-level></app-pov-level>
  `,
  directives: [PovLevelComponent]
})
class PovLevelComponentTestController {
}

Upvotes: 299

Views: 237469

Answers (4)

Arvind Chourasiya
Arvind Chourasiya

Reputation: 17452

.spec.ts file is used for unit testing of your application.

If you don't to get it generated just use --spec=false while creating new Component. Like this 

ng generate component --spec=false mycomponentName

Upvotes: 3

awiseman
awiseman

Reputation: 5724

The spec files are unit tests for your source files. The convention for Angular applications is to have a .spec.ts file for each .ts file. They are run using the Jasmine javascript test framework through the Karma test runner (https://karma-runner.github.io/) when you use the ng test command.

You can use this for some further reading:

https://angular.io/guide/testing

Upvotes: 371

Pritam Sinha
Pritam Sinha

Reputation: 71

The .spec.ts files are for unit tests for individual components. You can run Karma task runner through ng test. In order to see code coverage of unit test cases for particular components run ng test --code-coverage

Upvotes: 6

trueboroda
trueboroda

Reputation: 2890

if you generate new angular project using "ng new", you may skip a generating of spec.ts files. For this you should apply --skip-tests option.

ng new ng-app-name --skip-tests

Upvotes: 33

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