gulpfile.js

var gulp = require('gulp');
var fs = require('fs');
var $ = require('gulp-load-plugins')();
var del = require('del');
var runSequence = require('run-sequence');
var path = require('path');
var spawn = require('child_process').spawn;
var node;

var pkg = require('./package.json');

var dist = 'public/dist';
var src = 'public/src';
var PORT = process.env.PORT || 3000;
/**
 * $ gulp server
 * description: launch the server. If there's a server already running, kill it.
 */
gulp.task('server', function() {
    console.log("server");
    if (node) node.kill();
    node = spawn('node', ['app.js', PORT], {stdio: 'inherit'});
    node.on('close', function (code) {
        if (code === 8) {
            gulp.log('Error detected, waiting for changes...');
        }
    });

	// exec('mongod --dbpath ./data', function (err, stdout, stderr) {
	// 	console.log('starting mongo');
	// 	console.log(stdout);
	// 	console.log(stderr);
	// 	cb(err);
	// });
});

/**
 * $ gulp
 * description: start the development environment
 */
gulp.task('default', function() {

    gulp.watch('server');

    // gulp.watch(['*.js', 'custom_modules/*.*', 'custom_modules/**/*.*'], function() {
    //     console.log("watching be");
    //     runSequence('server');
    // });
	//
    // gulp.watch(['public/src/**/*.*'], function() {
    //     console.log("watching fe");
    //     runSequence('hex');
    // });
});

gulp.task('hex', function() {
	console.log("hex");
	gulp.src([src+'/vg.js', src+'/**/*.js', '!src/grids/Hex.js', '!src/grids/HexGrid.js'])
		.pipe($.plumber({errorHandler: handleErrors}))
		.pipe($.sourcemaps.init())
		.pipe($.concat('hex-grid.min.js'))
		.pipe($.uglify())
		.pipe($.sourcemaps.write('.'))
		.pipe(gulp.dest(dist))    

});

// clean up if an error goes unhandled.
process.on('exit', function() {
    if (node) run('default');
});


/*----------------------------------------------------------------------
	HELPERS
*/

function handleErrors() {
	var args = Array.prototype.slice.call(arguments);
	// Send error to notification center with gulp-notify
	$.notify.onError({
		title: 'Build error',
		message: '<%= error%>',
		showStack: true
	}).apply(this, args);

	// Keep gulp from hanging on this task
	this.emit('end');
}