How can I make a config file to import the same modules for multiple jest tests?

Question

I have tests for jest written in jsx files with these same lines of code:

import React from 'react';
import { configure } from 'enzyme';
import { shallow } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
configure({ adapter: new Adapter() });

How can I make a config file to include these every time instead of writing these in my test file?

Answer 1

You will still need to do

import React from 'react';
import { shallow } from 'enzyme';

in your unit tests since your tests need to use React and shallow but you can move

import { configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

into a separate file and configure that file to be run before each test.

If you bootstrapped your app using create-react-app v4 or higher and haven't ejected then you can put that code in src/setupTests.js

Otherwise you can configure Jest to run it as a setupTestFrameworkScriptFile