Make gulp look more like rake

gulpfile.js

/*
  gulpfile.js
  
  Gulp lacks a native way to provide task documentation or break tasks
  into multiple files. This gulpfile reads './tasks/*.js' and can list
  all available tasks with `gulp` or `gulp tasks`. If you set a .desc
  property on your task functions, those descriptions will show up in
  `gulp tasks` output. Tasks without descriptions will be omitted
  from this output (but still visible with `gulp -T`).
  
  Task files should export a function that takes the gulp object as its
  sole argument. E.g. `module.exports = function(gulp) { gulp.task... };`
  
  See the 'tasks' task in this file for an example task definition.
*/
var fs = require('fs');
var path = require('path');
var gulp = require('gulp');

var TASK_PATH = './tasks';

// Import other gulp taskfiles.
var taskFiles = fs.readdirSync(TASK_PATH);
taskFiles.forEach(function(file) {
	if (!file.match(/\.js$/)) return;
	require(path.resolve(TASK_PATH, file))(gulp);
});

gulp.task('default', ['tasks']);

gulp.task('tasks', tasks);
tasks.desc = 'List all gulp tasks';
function tasks() {
	var allTasks = Object.keys(gulp.tasks)
		.sort()
		.map(function(n) { return gulp.tasks[n]; });
	var taskNames = allTasks.map(function(t) { return t.name; });
	var maxLen = longestString(taskNames).length;

	console.log('');
	console.log('Available tasks:');
	console.log('================');

	allTasks.forEach(function(task) {
		if (task.name === 'default') return;
		if (!task.fn.desc) return;
		console.log('%s - %s', ljust(task.name, maxLen + 1), task.fn.desc);
	});

	console.log('');
}

function ljust(str, size) {
	return str + Array(size - str.length).join(' ');
}

function longestString(strings) {
	return strings.reduce(function(max, name) {
		return name.length > max.length ? name : max;
	}, '');
}