Mocha

Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser.

Lots of documentation is available on https://mochajs.org/ but here are a couple of notes that can be useful

NPM

• "test": "mocha --watch"

  • will launch mocha which is globally installed and log for scripts in the test folder "./test/*.js"

• "test": "mocha --recursive "./spec/*.js"

  • custom folder to look into can be configured

• "test:utils": "mocha --config utils/__tests__/.mocharc.js"

  • --config can precise the location of the config file .mocharc.js

*"test:dev": "mocha -r mocha.env.js --watch "

• -r can include a module; useful for exemple to set the environment:

  e.g process.env.NODE_ENV = 'development'

Config file .mocharc.js

e.g

(module.exports = {
    diff: true,
    extension: ['js'],
    package: './package.json',
    reporter: 'spec',
    slow: 75,
    timeout: 2000,
    ui: 'bdd',
    'recursive':['./utils/**/*.spec.js'],
    'watch-files': ['./utils/**/*.js', '**/*.spec.js'],
    'watch-ignore': ['lib/vendor']
})

more details and ideas for configuration on https://mochajs.org/#command-line-usage

Code coverage

• Install Istambul package npm i nyc --save-dev

• Edit the package.json to perform the coverage check of the test:

  {
  "scripts": {
    "test": "nyc --reporter=text mocha"
  }
  }