run-eslint-as-a-preloader.md

Run ESLint As A Preloader

You may already be running ESLint manually or as a script command via npm. You can also include it as part of the Webpack build process. By adding it as a preloader, Webpack will lint your JavaScript files before running other loaders. The results of linting will be reported in the terminal. Assuming you've already installed eslint and set up your .eslintrc file, all you need to do is npm install --save-dev eslint-loader and then add something like the following to your webpack.config.js file:

module: {
  preLoaders: [
    {
      test: /\.js$/,
      loaders: ['eslint'],
      exclude: /node_modules/,
    }
  ],
  ...
}

Running something like webpack -w will now lint your JavaScript before running other loaders.

Depending on your project, you may also want to include babel-eslint and eslint-plugin-react with your setup.