How to use custom babel config for jest?

Friday, September 24, 2021
How to use custom babel config for jest?

For Scenario where jest setup is not present in current React Project and you want to use a babel config unrelated to current setup, you can do the following setup.

jest.config.js

module.exports = {
  verbose: true,
  transform: { '^.+\\.js$': '<rootDir>/jestPreprocess.js' },
};

jest.preprocessor.js

const babelOptions = { presets: ['env'] }; // Place you .babelrc related config here

module.exports = require('babel-jest').createTransformer(babelOptions);

NOTE: When using babel-jest < 27, you must omit the .default part: require("babel-jest").createTransformer({ ....

package.json

"scripts": {
    "test": "jest --config jest.config.js --no-cache",
    // ...

No comments: