webpack-contrib
Karma Webpack
Use webpack to preprocess files in karma
Install
npm npm i -D karma-webpack
yarn yarn add -D karma-webpack
Usage
karma.conf.js
module.exports = (config) => {
config.set({
// ... normal karma configuration
// make sure to include webpack as a framework
frameworks: ['mocha', 'webpack'],
plugins: [
'karma-webpack',
'karma-mocha',
],
files: [
// all files ending in ".test.js"
// !!! use watched: false as we use webpacks watch
{ pattern: 'test/**/*.test.js', watched: false }
],
preprocessors: {
// add webpack as preprocessor
'test/**/*.test.js': [ 'webpack' ]
},
webpack: {
// karma watches the test entry points
// Do NOT specify the entry option
// webpack watches dependencies
// webpack configuration
},
});
}
Default webpack configuration
This configuration will be merged with what gets provided via karma's config.webpack.
const defaultWebpackOptions = {
mode: 'development',
output: {
filename: '[name].js',
path: path.join(os.tmpdir(), '_karma_webpack_') + Math.floor(Math.random() * 1000000),
},
stats: {
modules: false,
colors: true,
},
watch: false,
optimization: {
runtimeChunk: 'single',
splitChunks: {
chunks: 'all',
minSize: 0,
cacheGroups: {
commons: {
name: 'commons',
chunks: 'initial',
minChunks: 1,
},
},
},
},
plugins: [],
};
How it works
This project is a framework and preprocessor for Karma that combines test files and dependencies into 2 shared bundles and 1 chunk per test file. It relies on webpack to generate the bundles/chunks and to keep it updated during autoWatch=true.
The first preproccessor triggers the build of all the bundles/chunks and all following files just return the output of this one build process.
Webpack typescript support
By default karma-webpack forces .js files so if you test .ts files and use webpack to build typescript to javascript it works out of the box.
If you have a different need you can override by settig webpack.transformPath
// this is the by default applied transformPath
webpack: {
transformPath: (filepath) => {
// force *.js files by default
const info = path.parse(filepath);
return `${path.join(info.dir, info.name)}.js`;
},
},
Source Maps
You can use the karma-sourcemap-loader to get the source maps generated for your test bundle.
npm i -D karma-sourcemap-loader
And then add it to your preprocessors.
karma.conf.js
preprocessors: {
'test/test_index.js': [ 'webpack', 'sourcemap' ]
}
And tell webpack to generate sourcemaps.
webpack.config.js
webpack: {
// ...
devtool: 'inline-source-map'
}
Current Maintainers
Cody Mikol |
Previous Maintainers
Previous maintainers of the karma-webpack plugin that have done such amazing work to get it to where it is today.
Ryan Clark |
April Arcus |
Mika Kalathil |
Joshua Wiens
|
Will Farley
|
Daniela Valero
|
Jonathan Trang
|
Carlos Morales
|