nodeunit-lcov-coveralls-example

Example showing how to use the new nodeunit lcov reporter to publish coverage data to Coveralls from Travis.

Our example code is the quicksort algorithm.

How to

Setup package.json

Depend on nodeunit, jscoverage and coveralls:

npm install nodeunit jscoverage coveralls --save-dev

Next, add a coveralls script to "scripts"

"scripts": {
  "test": "nodeunit test",
  "coveralls": "jscoverage lib && QUICKSORT_COV=1 nodeunit --reporter=lcov test | coveralls"
}

By creating our own custom NPM script, we can still use the npm test command without having to instrument and send data to coveralls.

The "coveralls" script does a few things:

0. Run jscoverage for all files in the lib directory. By default jscoverage will output instrumented files to lib-cov.
1. Define a env variable called QUICKSORT_COV to signal to the application it should use code that has been instrumented by jscoverage.
2. Run nodeunit for all files in the directory test, using the lcov reporter to output the coverage report to stdout.
3. Pipe the lcov report to coveralls, which in turn submits the report to coveralls.io.

You can run the coveralls script via npm run coveralls

Require instrumented code

Above we hinted that by defining an environment variable called QUICKSORT_COV our tests would use instrumented code. Our index.js looks like:

module.exports = process.env.QUICKSORT_COV
  ? require('./lib-cov/quicksort')
  : require('./lib/quicksort')

When nodeunit runs test/quicksort.js, it requires the quicksort index.js file:

var quickSort = require('../');

Submit to coveralls

To submit to coveralls you'll either need to add a .coveralls.yml file with your repo secret key to your project root (which you shouldn't commit to github!) or submit your coverage via Travis. If you're using a .coveralls.yml file you can simply run npm run coveralls and your code coverage will appear (assuming you first enabled the repository on the coveralls website). If you're using Travis, you need to add a .travis.yml file that runs your tests and submits the report:

language: node_js
node_js:
  - "0.10"
after_script:
  - npm run coveralls