Have a look at the Jest documentation for Webpack integration. The problem is that Jest can’t work with other stuff than JavaScript. So you have to mock all non-JavaScript files you import. The easiest way is to configure a moduleNameMapper in your Jest configuration.
{
"jest": {
"moduleNameMapper": {
"\\.(css|scss)$": "<rootDir>/__mocks__/styleMock.js"
}
}
}
With a __mocks__/styleMock.js, that looks like this.
module.exports = {};