Welcome to this hands-on AngularJS testing tutorial for beginners!
Testing is crucial for building robust AngularJS applications, yet many developers find it challenging. This tutorial aims to make testing Angular code straightforward through easy-to-follow examples.
Following core testing principles around isolation and mocking, you will gain practical experience creating maintainable tests that catch issues rapidly. By the end, you will have the essential skills to build production-grade AngularJS applications that meet functionality, compatibility, reliability and performance requirements.
With a focus on simplicity and real-world applicability, AngularJS Testing Tutorial will give you the testing confidence to create bug-free AngularJS apps.
So let’s get started!
Common AngularJS Testing Tools
· Cypress – End-to-end testing framework that runs directly in modern browsers
· Karma – Test runner for unit testing AngularJS code
· Protractor – End-to-end test framework for AngularJS applications
AngularJS Applications – Key Components
When building AngularJS applications, developers work with several key components that make up the structure and functionality of the app. These components work together to create the logic, views, and underlying services that power the user experience.
Controllers.
They are JavaScript functions that provide the business logic behind views. In the MVC design pattern, controllers act as the controllers. They handle user input, manipulate data, and decide what content to render.
Developers actively create controllers to connect AngularJS scopes to views.
Views
Developers actively define views using HTML to render data from controllers and models. Views utilize data binding to automatically update when model data changes. This eliminates the need to actively update views manually.
Models
They can be simple JavaScript objects or be derived from a persistence framework like Firebase. Developers actively create model objects and structures to represent the application data concepts suitable for views.
Services
Developers actively create AngularJS services to do work like making API calls without cluttering controller code. Services can be shared across the application increasing flexibility and reuse.
Modules
Developers actively define modules using ng-app which define the application dependencies and entry component. This boosts organisation and maintains a separation of concerns.
When developers leverage these key components, they can actively build robust AngularJS web apps with a clean separation of concerns between the different layers. The flexibility of AngularJS components allows for crafting complex, data-driven user experiences.
Unit Testing in AngularJS
AngularJS unit testing is essential for building high-quality applications. It validates that individual components like controllers, directives and services function as expected.
Unit testing catches bugs early, enables safe refactoring of code, and simplifies integrating code from different developers.
Before an AngularJS application can be considered production-ready, it should undergo thorough unit testing. This detects issues in the code at the earliest stage possible during the development lifecycle.
Robust unit testing leads to applications that are more reliable, better optimized, and more aligned with business requirements. It also enables diagnosing and fixing bugs rapidly. Unit-tested code also gives users greater confidence in the capabilities of the application.
Fundamentals of Unit Testing in AngularJS
When writing unit tests for your AngularJS code, following core fundamentals will ensure your test suite is robust, maintainable, and sustainable as your app evolves:
· Isolate Dependencies:
Each unit test should test one specific component in isolation without relying on other modules or external dependencies. Use mocks, spies and stubs to simulate dependencies.
· Arrange, Act, Assert (AAA):
Structure your test into 3 clearly defined sections – arrange test data/inputs, execute logic to test (act), and assert expected output was produced.
· One Assertion Per Test:
Every test case should validate one behaviour or output to make it easy to identify what failed. Avoid assertions that check multiple outputs.
· Make Tests Independent:
Write test cases to set up their own test data so they can run independently and not rely on the order of execution. Helpful when running tests in parallel.
· Keep Tests Short and Readable:
Break down lengthy test cases into smaller helper functions that each test a single behaviour or subunit of a component.
Following these fundamental guidelines will ensure your AngularJS unit test suite remains robust and easy to extend over time as application complexity grows.
Setting Up Your Environment
Just follow these steps:
· Install Node.js on your computer. This is the framework we’ll build on.
· Open your favorite code editor. We recommend Visual Studio Code, Brackets or Sublime Text. Any of these will work great.
· Create a new folder called “unit-testing” on your computer using the mkdir command. This is where you’ll store your test files.
· Open the unit-testing folder in your code editor and open a terminal window inside it.
Create package.json
npm initInstall Angular:
npm I angular –saveInstall Karma:
npm i -g karma –save -devInstall Jasmine:
npm I karma-jasmine jasmine-core –save -devInstall Angular mocks:
npm I angular-mocks –save -devInstall Karma Chrome browser:
npm I karma-chrome-launcher –save-dev
· In your unit-testing folder, create two new folders called “app” and “test”.
· Next, inside the unit-testing folder, create a new file called karma.config.js.
· Open karma.config.js in your code editor and type “karma init”. This will initialize an empty repository with some standard settings.
· You’ll be asked a series of questions about how you want to configure Karma. Answer them based on your preferences. The defaults are fine too.
End-to-End Testing in AngularJS with Protractor or Cypress
End-to-end (E2E) testing simulates how a real user would interact with your application from start to finish. It goes beyond unit testing by validating that all components work together properly.
Unit tests are limited because they only evaluate single parts of code in isolation. E2E testing is significant for catching issues that emerge when you string those building blocks into full workflows.
For example, unit tests could validate that a login form and database query work as expected. But E2E testing logs in with real credentials clicks around, pulls actual data, and more.
E2E testing provides confidence that your application functions smoothly under real-world conditions. It finds gaps that fall between unit and integration testing. Doing E2E testing right is crucial for shipping quality software that meets business and user requirements from end to end.
Benefits of End-to-End Testing
Doing comprehensive end-to-end testing provides several important benefits:
· Catches more bugs upfront, leading to higher quality software
· Ensures all components work together smoothly, increasing confidence
· Models real-world user workflows, enhancing user experience
· Saves time and money by fixing issues earlier rather than later
· Promotes collaboration across teams working on different components
· Automates repetitive tests, boosting productivity
· Accelerates time-to-market by reducing defects before release
E2E testing delivers more robust, reliable software that meets business and user needs. It validates quality from start to finish across the entire application. Investing in E2E testing pays dividends through faster delivery of better software.
Setting up the testing environment with Protractor and Cypress
Setting Up Cypress for E2E Testing
Create a new project folder and initialize it:
npm init
Install Cypress in the project folder:
npm install cypress –save-dev
Or with Yarn:
yarn add cypress –dev
This installs the latest version of Cypress (v12.11.0 at time of writing) locally as a dev dependency.
And that’s it! With Cypress installed, you can now begin creating and running end-to-end tests for your application within the new project.
- Writing and running endtoend tests with Protractor or Cypress
- Best practices for endtoend testing in AngularJS with Protractor or Cypress
Installing Protractor for E2E Testing
Prerequisite: Node.js must be installed.
1. Open a terminal and type:
npm install -g protractor
2. This installs two command line tools:
– protractor – The test runner
– webdriver-manager – Manages the Selenium webdriver
3. Verify the installation with:
protractor –version
This will install the latest Protractor version globally on your system. The test runner and Selenium manager will now be available from the command line to start end-to-end testing your application.
Integration Testing in AngularJS
Integration testing validates that different units or components of an application work correctly when combined together.
It differs from unit testing, which focuses on testing individual units in isolation. And it differs from end-to-end (E2E) testing, which replicates entire user workflows in the app.
Instead, integration testing confirms that interactions between integrated units are functioning as expected. For example, it can test that the UI layer successfully calls and displays data from an API endpoint.
So while unit testing examines individual modules and E2E checks overall flows, integration testing focuses on verifying the connections between integrated components. It ensures units collaborate properly when assembled, even while relying on networks, databases, or other external resources.
Setting up the testing environment and Writing and running integration tests
Set up an Angular Project
Step 1.
To create a new Angular project, type the following command in your terminal or command prompt:
ng new angular-todo-app
Replace angular-todo-app with whatever name you prefer for your app.
After that, press the enter key. Wait a bit as Angular sets up your new project.
Step 2.
Now you have your new project. It comes with with Angular’s built-in testing tool. This allows for straight testing without any further set up.
AngularJS automatically generates test files for TypeScript components created with the Angular CLI. For example, navigate to app > components > todo and you will see a todo.component.spec.ts test file that corresponds to todo.component.ts.
This pattern can be seen throughout an Angular project – each component has an accompanying *.spec.ts spec file to house its tests.
For our integration test, we will leverage the default app.component.spec.ts file that Angular generates in the root app folder.
This spec file is connected to the main app.component.ts and allows us to write tests validating integration points with other services and components.
Angular takes care of wiring up the test environment for us in app.component.spec.ts, making it a great starting point for our first integration test.
Step 3. Create and Set up a Test Suite
Open the app.component.specs.ts where you will create a new test suite. Use the following codes
describe(‘TodoList Integration’, () => {
let component: AppComponent;
let fixture: ComponentFixture<AppComponent>;
let service: TodoService;
beforeEach(async () => {
await TestBed.configureTestingModule({
imports: [FormsModule],
declarations: [AppComponent, TodoComponent],
providers: [
{
provide: TodoService,
useValue: {
getTasks: () => {
return dummyTodos;
}
}
}
]
}).compileComponents();
fixture = TestBed.createComponent(AppComponent);
component = fixture.componentInstance;
service = TestBed.inject(TodoService);
});
});
const dummyTodos = [
{
id: 1,
title: ‘Todo 1’,
completed: false
},
{
id: 2,
title: ‘Todo 2’,
completed: false
}
];
• Async test setup with beforeEach
• Configure and compile the testing module
• Create component fixture and instances
• Define dummy data outside to reuse
• Fetch injections using TestBed.inject
Step 4.
it(‘should load todos from service’, async(() => {
fixture.detectChanges();
expect(component.todos.length).toBe(2);
expect(service.getTasks()).toEqual(dummyTodos);
}));
In this test:
• Use `it()` to define the test case
• Call detectChanges() to trigger data binding
• Assert component todos array length
• Assert equality between service and dummy data
Some key points:
• Made test name more generic
• Leveraged async test function
• Checked length first as an indirect check
• Compared service data directly to dummy data
Step 5.
This is where you run the test
// Run all test suites
ng test
// Run a specific test file
ng test –include file-name
To execute the integration tests:
• Open a terminal/command prompt
• Navigate to the project root
• Run `ng test` to run all specs
• Or run `ng test –include <file-name>` to run a specific test file
Angular will:
• Set up the test environment
• Execute the test cases
• Report results in CLI and browser-based runner
Some key points:
• `ng test` runs all specs by default
• Can filter by file name as needed
• Results output to terminal and browser test runner
Testing Directives in AngularJS
- Explanation of directives in AngularJS
- Setting up the testing environment for directives
- Writing and running tests for directives
- Best practices for testing directives in AngularJS
AngularJS Testing Tutorial and AngularJS Testing Services
Services are one of the most important building blocks in AngularJS applications. They provide reusable business logic that can be leveraged across components. But how do you make sure your services have robust test coverage in AngularJS?
This easy AngularJS testing tutorial section offers best practices for unit testing your services. Let us dive in.
· Set up the AngularJS testing framework and environment from scratch
· Effectively mock dependencies your services interact with
· Validate service behavior through well-structured test specs
· Identify relevant use cases to test that maximize coverage
· Organize tests for maintainability as the codebase evolves
· Integrate services with other key pieces like components
· Debug issues when services don’t perform as expected
Testing services well uncovers flaws early and gives confidence that business rules enforce data integrity. Save hours down the road by learning how to test AngularJS services the right way. Equip yourself with an in-demand skill that delivers higher quality software.
The concepts apply whether you are just starting out or have already built AngularJS applications. Advanced developers can use these AngularJS testing best practices to optimize existing test suites. You can explore more on this on this site.
Testing Controllers in AngularJS
Controllers are the backbone of dynamic behavior in AngularJS applications. They connect the user interface to underlying logic. Testing controllers thoroughly prevents interface mishaps down the road.
With a reliable test suite, you can simulate user interactions and validate that controllers transform and present data correctly. This allows you to confidently evolve features knowing you can catch regressions very early.
Here is a dedicated AngularJS testing tutorial section that reveals controller testing best practices.
Injecting Services into AngularJS Controllers
When unit testing controllers, you’ll need to mock out its dependencies. Services like $http or custom providers enable controllers to offload business logic.
There are two standard ways to inject these dependencies so they get resolved properly:
Inline Array
Define an inline array listing the dependencies – handy for simple cases:
angular.module(‘myApp’)
.controller(‘MyController’, [‘$scope’, ‘MyService’, function($scope, MyService) {
// …
}]);
$inject Property
Or set a $inject property on the controller function:
angular.module(‘myApp’)
.controller(‘MyController’, MyController);
MyController.$inject = [‘$scope’, ‘MyService’];
function MyController($scope, MyService) {
// …
}
Either approach works for mocking in tests. The key is listing dependencies explicitly rather than relying on inference.
This ensures dependencies resolve correctly when code is minified/uglified during the build process – a key AngularJS testing best practice.
Conclusion of our AngularJS Testing Tutorial
Congratulations if you read our AngularJS testing tutorial to this level. You now have the fundamental knowledge and skills to start building robust test suites for your AngularJS applications.
Testing may seem daunting at first. But sticking with it pays huge dividends down the road in terms of application stability, faster delivery, and improved user experience. Be patient and don’t forget to apply testing best practices like isolation, mocking, and readable test organization.
This was just the beginning – there is so much more to explore as you become a seasoned AngularJS testing expert. You need to explore more and deeper topics like testing directives, end-to-end testing frameworks like Protractor and Cypress, visual regression testing, and advanced techniques for tricky test scenarios.
While you search through different AngularJS Testing Tutorials, the key is to stay positive, start testing early, refactor regularly, and reach out when you need help. Continually practising AngularJS testing will cement what you’ve learned and build real confidence. You’ve got this!
