Grunt performance

/**
 * Execute "grunt test-speed" in order to see duration for each case
 */
module.exports = function(grunt) {
    require('load-grunt-tasks')(grunt);

    grunt['initConfig']({
        pkg: grunt.file.readJSON('package.json'),

        concurrent: {
            target1: ['long1', 'long2']
        }
    });


    grunt.registerTask('long1', 'Long task 1', function(){
        var fs = require('fs');
        for(var i=0; i<1000000; i++) {
            fs.existsSync(i) && console.log('foo');
        }
        console.log('long task 1 finished');
    });

    grunt.registerTask('long2', 'Long task 2', function(){
        var fs = require('fs');
        for(var i=0; i<1000000; i++) {
            fs.existsSync(i) && console.log('foo');
        }
        console.log('long task 1 finished');
    });

    grunt.registerTask('date', 'print date', function(){
        console.log((new Date()));
    });

    //Run long tasks one after other
    grunt.registerTask('long', ['long1', 'long2']);

    //Run long tasks in parallel
    grunt.registerTask('p-long', ['concurrent:target1']);

    //Measure speed in both cases
    grunt.registerTask('test-speed', ['date', 'p-long', 'date', 'long', 'date']);
};