Simple and complete Angular testing utilities that encourage good testing practices.
- Table of Contents
- The problem
- This solution
- Example
- Installation
- Version compatibility
- Guiding Principles
- Contributors
- Docs
- FAQ
- Issues
- Getting started with GitHub Codespaces
- LICENSE
You want to write maintainable tests for your Angular components. As a part of this goal, you want your tests to avoid including implementation details of your components and rather focus on making your tests give you the confidence for which they are intended. As part of this, you want your testbase to be maintainable in the long run so refactors of your components (changes to implementation but not functionality) don't break your tests and slow you and your team down.
The @testing-library/angular is a very lightweight solution for
testing Angular components. It provides light utility functions on top of Angular
and @testing-library/dom, in a way that encourages better testing practices. Its
primary guiding principle is:
The more your tests resemble the way your software is used, the more confidence they can give you.
counter.component.ts
@Component({
selector: 'app-counter',
template: `
<span>{{ hello() }}</span>
<button (click)="decrement()">-</button>
<span>Current Count: {{ counter() }}</span>
<button (click)="increment()">+</button>
`,
})
export class CounterComponent {
counter = model(0);
hello = input('Hi', { alias: 'greeting' });
increment() {
this.counter.set(this.counter() + 1);
}
decrement() {
this.counter.set(this.counter() - 1);
}
}counter.component.spec.ts
import { render, screen, fireEvent, aliasedInput } from '@testing-library/angular';
import { CounterComponent } from './counter.component';
describe('Counter', () => {
it('should render counter', async () => {
await render(CounterComponent, {
inputs: {
counter: 5,
// aliases need to be specified this way
...aliasedInput('greeting', 'Hello Alias!'),
},
});
expect(screen.getByText('Current Count: 5')).toBeVisible();
expect(screen.getByText('Hello Alias!')).toBeVisible();
});
it('should increment the counter on click', async () => {
await render(CounterComponent, { inputs: { counter: 5 } });
const incrementButton = screen.getByRole('button', { name: '+' });
fireEvent.click(incrementButton);
expect(screen.getByText('Current Count: 6')).toBeVisible();
});
});This module is distributed via npm which is bundled with node and
should be installed as one of your project's devDependencies.
Starting from ATL version 17, you also need to install @testing-library/dom:
npm install --save-dev @testing-library/angular @testing-library/domOr, you can use the ng add command.
This sets up your project to use Angular Testing Library, which also includes the installation of @testing-library/dom.
ng add @testing-library/angularYou may also be interested in installing jest-dom so you can use
the custom jest matchers.
| Angular | Angular Testing Library |
|---|---|
| 18.x | 17.x, 16.x, 15.x, 14.x, 13.x |
| 17.x | 17.x, 16.x, 15.x, 14.x, 13.x |
| 16.x | 14.x, 13.x |
| >= 15.1 | 14.x, 13.x |
| < 15.1 | 12.x, 11.x |
| 14.x | 12.x, 11.x |
The more your tests resemble the way your software is used, the more confidence they can give you.
We try to only expose methods and utilities that encourage you to write tests that closely resemble how your Angular components are used.
Utilities are included in this project based on the following guiding principles:
- If it relates to rendering components, it deals with DOM nodes rather than component instances, nor should it encourage dealing with component instances.
- It should be generally useful for testing individual Angular components or full Angular applications.
- Utility implementations and APIs should be simple and flexible.
At the end of the day, what we want is for this library to be pretty light-weight, simple, and understandable.
Thanks goes to these people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome!
I am using Reactive Forms and the jest-dom matcher toHaveFormValues always returns an empty object or there are missing fields. Why?
Only form elements with a name attribute will have their values passed to toHaveFormsValues.
Looking to contribute? Look for the Good First Issue label.
Please file an issue for bugs, missing documentation, or unexpected behavior.
Please file an issue to suggest new features. Vote on feature requests by adding a 👍. This helps maintainers prioritize what to work on.
For questions related to using the library, please visit a support community instead of filing an issue on GitHub.
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Note: Dev containers is an open spec which is supported by GitHub Codespaces and other tools.
MIT