Istanbul plugin for Webpack

Istanbul code coverage loader for Webpack

Istanbul code coverage loader for Webpack

Cross-Platform Compatibility Build Status

Coverage Status Dependencies

npm License

This is a Webpack loader that uses Istanbul to add code coverage instrumentation to your code. This is especially useful for in-browser testing, in a tool like Karma, where you can use karma-coverage-istanbul-reporter to output code coverage data in a variety of formats that are supported by services like Coveralls or Codacy.

Coverage Istanbul Loader is based on Istanbul Instrumenter Loader, but uses a newer version of the Istanbul API and has better support for source maps.


See the examples folder for usage examples for various use cases.


Contributions, enhancements, and bug-fixes are welcome! File an issue on GitHub and submit a pull request.


To build/test the project locally on your computer:

  1. Clone this repo
    git clone

  2. Install dependencies
    npm install

  3. Build the code
    npm run build

  4. Run the tests
    npm test


coverage-istanbul-loader is 100% free and open-source, under the MIT license. Use it however you want.

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