Hello all,

This is a quick tip to make a npm script which make Istanbul coverage utility works with Mocha.

1. First run in terminal in your project root:

   npm install --save-dev istanbul mocha

2. Then modify your test script as follows:

   "scripts": {
       "test": "./node_modules/istanbul/lib/cli.js cover node_modules/mocha/bin/_mocha -- -R spec test/**/*",
   }
   

3. Run in terminal:

   npm test

Bingo! Now your coverage are being generated in the coverage folder. The tricky part was using “bin/_mocha” instead of the “bin/mocha”.

Have a good day!