Gruntfile.js

var coverageFolder = process.env.CIRCLE_TEST_REPORTS == undefined ? 'coverage' : process.env.CIRCLE_TEST_REPORTS + '/coverage';
module.exports = function(grunt) {

    // Project configuration.
    grunt.initConfig({
      pkg: grunt.file.readJSON('package.json'),
      mochaTest: {
        local: {
          options: {
            reporter: 'spec',
            //captureFile: 'results.txt', // Optionally capture the reporter output to a file
            quiet: false, // Optionally suppress output to standard out (defaults to false)
            clearRequireCache: false, // Optionally clear the require cache before running tests (defaults to false)
            ui: 'tdd'
          },
          src: ['test/**/*.js']
        },
        circleci: {
          options: {
              ui: 'tdd',
              reporter: 'mocha-junit-reporter',
              quiet: false,
              reporterOptions: {
                  mochaFile: process.env.CIRCLE_TEST_REPORTS + '/mocha/results.xml'
              }
          },
          src: ['test/**/*.js']
        },
        shippable: {
          options: {
            ui: 'tdd',
            reporter: 'mocha-junit-reporter',
            quiet: false,
            reporterOptions: {
              mochaFile: 'shippable/testresults/mocha/results.xml'
            }
          },
          src: ['test/**/*.js']
        },
      },

      mocha_istanbul: {
          coverage: {
              src: 'test', // a folder works nicely
              options: {
                  mochaOptions: ['--ui', 'tdd'], // any extra options for mocha
                  istanbulOptions: ['--dir', coverageFolder],
                  reporter: 'spec',
                  reportFormats: ['html', 'lcovonly']
              }
          }
      }

    });

    // Load the plugin that provides the "uglify" task.
    // grunt.loadNpmTasks('grunt-mocha'); Client Side testing
    grunt.loadNpmTasks('grunt-mocha-test');
    grunt.loadNpmTasks('grunt-mocha-istanbul');

    // Default task(s).
    grunt.registerTask('default', []);

    // Test
    grunt.registerTask('test', ['mochaTest:local']);

    // CircleCI
    grunt.registerTask('circleci', ['mochaTest:circleci', 'mocha_istanbul']);

    grunt.registerTask('shippable', ['mochaTest:shippable', 'mocha_istanbul']);

    //Coverage
    grunt.registerTask('coverage', ['mocha_istanbul']);

};