Working with unit and integration tests in React Native

When you start a new React Native project, it comes with a testing framework called Jest preconfigured. This is the recommended framework for unit tests, integration tests, and component tests. We’ll use it in the following sections.

Let’s start with unit testing. We’ll use our example project again, but we will go back a few commits to use the local movie service implementation. You can have a look at the complete code by selecting the chapter-12-unit-testing branch in the example repository.

This local service implementation is very suitable as an example for unit testing because it has no dependencies. We know the data it is working on and can write tests very easily. In this example, we’ll test two API calls: getMovies and getMovieById.

The following code shows our first unit tests:

import {getMovies,getMovieById} from '../src/services/movieService';
describe('testing...