DOM Testing Library (works with React and Angular)

The tests resemble the way your software is used, and so you have more real-life confidence

Reference: 

https://testing-library.com/docs/guiding-principles

The Problem

Need confidence that your components are working for your users.

Need to maintainable

Avoid implementation details (so they can handle refactors)

The solution 

Light weight

Tests web pages by querying and interacting with DOM nodes.

The DOM nodes can be simulated or in the browser

Find nodes in the same way that a user would

Notes:

Not a Test runner or framework

Limited to a testing framework

Notes (avoid these)

Avoid these implementation details

1. Internal state of a component
2. Internal methods of a component
3. Lifecycle methods of a component
4. Child components

The @testing-library family of packages helps you test UI components in a user-centric way.

Can be run in simulated mode or in an actual browser.

Works with DOM APIS such as

• Jest
• Mocha
• Mocha + JSDOM

Actual browsers