Babel with Jest, ESLint, Prettier, and Wallaby

Bridging Jest and Babel

Let’s bring Jest to the party.

• In order to get Jest to run tests through Babel, you’ll need both jest and a package called babel-jest:

  $ npm install --save-dev jest@23.6.0 babel-jest@23.6.0
  + jest@23.6.0
  + babel-jest@23.6.0
  

• As of this writing, you’ll also need a special version of the babel-core package. The reason is that the package recently switched names. Babel 6 called it babel-core, but Babel 7 namespaces it as @babel/core. So this package creates a bridge for projects looking for babel-core to direct them to @babel/core:

  $ npm install --save-dev babel-core@^7.0.0-bridge.0
  + babel-core@^7.0.0-bridge.0
  

• Next, update the scripts entry in package.json to make Jest the project’s official test runner: