@godeltech/angular-testing

Build

Npm

Introduction

Angular package that helps to setup BeforeAll TestBed configuration easily. It allows you to improve the speed of tests run by 3-5 times and without any changes in your existing tests. Also it has methods which help to trigger common html event actions.

Installation

$ npm i @godeltech/angular-testing

Description

By default angular offers you to setup TestBed configureTestingModule before each test. You can increase tests execution speed with single setup configuration for all tests in the file, but creating an instance will also be before each test as the main rule in unit testing.

For comparison I took one component with simle functionality, see demo project, covered it with 11 tests, firstly with BeforeEach setup and then with BeforeAll. I duplicated them in 30 files with 110 tests in each of them. The result was 3300 tests with each of the setups. All tests are the same for all setups, just configuration is different.

In the sheet below you can see time duration in seconds for building karma configuration, tests run and total sum.

Setup configuration	Number of tests	Build run	Tests run	Total
BeforeEach	3300	30	72	102
BeforeEach	1650	29	30	59
BeforeEach	1100	29	18	47
BeforeAll	3300	28	18.5	46.5
BeforeAll	1650	28	7	35
BeforeAll	1100	28	3	31

Usage

Replace beforeEach setup with BaseTest.setupTestBed

beforeEach(() => TestBed.configureTestingModule(moduleDef: TestModuleMetadata));

BaseTest.setupTestBed(moduleDef: TestModuleMetadata)

Example

import { BaseTest, EventHandler } from '@godeltech/angular-testing';
import { ComponentFixture, TestBed } from '@angular/core/testing';

import { AppComponent } from './app.component';

describe('AppComponent', () => {
    let component: AppComponent;
    let fixture: ComponentFixture<AppComponent>;

    BaseTest.setupTestBed({
        declarations: [AppComponent]
    });

    beforeEach(() => {
        fixture = TestBed.createComponent(AppComponent);
        component = fixture.componentInstance;
    });

    afterEach(() => {
        fixture.destroy();
    });

    it('should create an instance', () => {
        fixture.detectChanges();

        expect(component).toBeTruthy();
    });
});

Look at the demo project to see more examples

EventHadnler Helper

• click - Simulate element single click. Default option is mouse left-button event click.
• dblclick - Simulate element dblclick click. Default option is mouse left-button event click.
• scroll - Simulate element scroll via mousewheel. Default option is scroll down event.
• submit - Simulate form submit. Default option is mouse left-button event click.
• focus - Simulate element focus.

In template

<button class="toggle-btn" (click)="onContainerToggle()">home</button>

In component

showContainer: boolean;

onContainerToggle(): void {
    this.service.showContainer(!this.showContainer);
}

In tests

it('toggle-btn element: should call app service', () => {
    // arrange
    fixture.detectChanges();
    const element = fixture.debugElement.query(By.css('.toggle-btn'));

    // act
    EventHandler.click(element);

    // assert
    expect(appServiceMock.showContainer).toHaveBeenCalledTimes(1);
});

Additional Information

As a result of using the single setup configuration for all tests in the file you should use global variables for your providers. It means that after each test your setup providers are not overwritten. Don't forget to reset values of your global variables.

describe('AppComponent', () => {
    let component: AppComponent;
    let fixture: ComponentFixture<AppComponent>;
    const appServiceMock = {
        showContainer: jasmine.createSpy('showContainer'),
        showContainer$: new Subject<boolean>()
    };

    BaseTest.setupTestBed({
        declarations: [AppComponent],
        providers: [{ provide: AppService, useValue: appServiceMock }],
        schemas: [NO_ERRORS_SCHEMA]
    });

    beforeEach(() => {
        fixture = TestBed.createComponent(AppComponent);
        component = fixture.componentInstance;
        resetMockedProviders();
    });

    afterEach(() => {
        fixture.destroy();
    });
    
    it('should create an instance', () => {
        fixture.detectChanges();

        expect(component).toBeTruthy();
    });
    
    function resetMockedProviders(): void {
        appServiceMock.showContainer.calls.reset();
    }
});