Jest

Mocking assets

With Jest, you can mock out any type of assets such as scss, like so:

Add the following to your package.json:

{
   "jest":{
        "moduleNameMapper":{
             "\\.(css|less|sass|scss)$": "<rootDir>/__mocks__/styleMock.js",
             "\\.(gif|ttf|eot|svg)$": "<rootDir>/__mocks__/fileMock.js"
        }
   }
}

The styleMock.js or fileMock.js contents should be:

module.exports = {};

To mock out SVG, PNG and other assets, use jest-transform-stub library:

yarn add --dev jest-transform-stub

Edit package.json:

{
   "jest":{
        "moduleNameMapper":{
             "\\.(css|less|sass|scss|svg|png)$": "jest-transform-stub"
        }
   }
}