https://github.com/webpack/karma-webpack

karma-webpack

Installation

npm install --save-dev karma-webpack

Usage

// Karma configuration

module.exports = function(config) {
    config.set({
        // ... normal karma configuration

        files: [
            // all files ending in "_test"
            'test/*_test.js',
            'test/**/*_test.js'
            // each file acts as entry point for the webpack configuration
        ],

        preprocessors: {
            // add webpack as preprocessor
            'test/*_test.js': ['webpack'],
            'test/**/*_test.js': ['webpack']
        },

        webpack: {
            // karma watches the test entry points
            // (you don't need to specify the entry option)
            // webpack watches dependencies

            // webpack configuration
        },

        webpackMiddleware: {
            // webpack-dev-middleware configuration
            // i. e.
            noInfo: true
        },

        plugins: [
            require("karma-webpack")
        ]

    });
};

Alternative usage

This configuration is more performant, but you cannot run single test anymore (only the complete suite).

The above configuration generates a webpack bundle for each test. For many testcases this can result in many big files. The alterative configuration creates a single bundle with all testcases.

        files: [
            // only specify one entry point
            // and require all tests in there
            'test/test_index.js'
        ],

        preprocessors: {
            // add webpack as preprocessor
            'test/test_index.js': ['webpack']
        },

// test/test_index.js

// require all modules ending in "_test" from the
// current directory and all subdirectories
var testsContext = require.context(".", true, /_test$/);
testsContext.keys().forEach(testsContext);

Every test file is required using the require.context and compiled with webpack into one test bundle.

Source Maps

You can use the karma-sourcemap-loader to get the source maps generated for your test bundle.

npm install --save-dev karma-sourcemap-loader

And then add it to your preprocessors

preprocessors: {
    'test/test_index.js': ['webpack', 'sourcemap']
}

And tell webpack to generate sourcemaps

webpack: {
  // ...
    devtool: 'inline-source-map'
}

Options

This is the full list of options you can specify in your Karma config.

webpack

Webpack configuration.

webpackMiddleware

Configuration for webpack-dev-middleware.

License

MIT