Istanbul code coverage loader for Webpack

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Coverage Istanbul Loader is based on Istanbul Instrumenter Loader, but uses a newer version of the Istanbul API and has better support for source maps.

Usage

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

• "hello, world" example This is the most simplistic example. It just uses coverage-istanbul-loader with its default options to produce an output bundle that contains code coverage instrumentation.

• TypeScript example This example demonstrates using coverage-istanbul-loader with transpiled code. It correctly maps the instrumented JavaScript code back to the original TypeScript source code.

• Karma example This example demonstrates using coverage-istanbul-loader with Karma and karma-coverage-istanbul-reporter to produce code coverage reports for browser tests.

• Example with options This example demonstrates passing options to coverage-istanbul-loader. The options are passed-on to istanbul-lib-instrument, so all the same options are supported.

Contributing

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

Building/Testing

To build/test the project locally on your computer:

1. Clone this repo git clone https://github.com/JS-DevTools/coverage-istanbul-loader.git

2. Install dependencies npm install

3. Build the code npm run build

4. Run the tests npm test

License

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

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