gulpfile.js

var gulp = require('gulp');
var spawn = require('child_process').spawn;
var gutil = require('gulp-util');
var gmocha = require('gulp-mocha');
var gwatch = require('gulp-watch');
var gbatch = require('gulp-batch');

function testsTaskHandler ( callback ) {
  var paths = [
    './test/**/*.test.js',
    '--timeout 50000',
    '--reporter spec'
  ];
  var mocha = spawn('mocha', paths);

  function print ( data ) {
    process.stdout.write( data.toString('utf-8') );
  }

  mocha
    .stdout
    .on('data', print);

  mocha
    .stderr
    .on('data', print);

  mocha
    .on('close', callback);
}
gulp.task( 'tests', testsTaskHandler );

function watchTaskHandler ( callback ) {
  var paths = [
    './modules/**/*.js',
    './models/**/*.js',
    './routes/**/*.js',
    './middlewares/**/*.js',
    './test/**/*.test.js',
  ];
  var srcOpts = { read: false };

  function watchHandler ( events, callback ) {
    testsTaskHandler( callback );
  }
  gulp.watch( paths, gbatch( watchHandler ) ); 
}
gulp.task( 'watch', watchTaskHandler );
gulp.task('default', [ 'watch' ]);