A simplistic NodeJS HTTP server

server.js

var http = require('http'),
	path = require('path'),
	fs = require('fs'),
	optional = require('optional'),
	sass = optional('node-sass')
 
http.createServer(function(req, res) {
	var fileName = req.url == '/' ? '/index.html' : decodeURIComponent(req.url),
		filePath = __dirname + '/www' + fileName,
		ext = fileName.lastIndexOf('.') > -1 ? fileName.substring(fileName.lastIndexOf('.') + 1) : 'html'
	console.log('Requested ' + req.url)
	fs.exists(filePath, function(exists) {
		if (exists) switch (ext) {
		case 'sass':
		case 'scss':
			var outFile = filePath.substring(0, filePath.lastIndexOf('.')) + '.css',
				iFileStats, oFileStats, noFile = false
			// Test for outFile
			try {
				fs.readFileSync(outFile)
			} catch (e) {
				// Create outFile
				fs.writeFileSync(outFile, '')
				noFile = true // but still need to compress SCSS
			}
			iFileStats = fs.statSync(filePath)
			oFileStats = fs.statSync(outFile)
			// Only Compress Updated File
			if (noFile || iFileStats.mtime.getTime() > oFileStats.mtime.getTime()) sass.render({
				outputStyle:'compressed',
				indentType:'tab',
				outFile:outFile,
				file:filePath
			}, function(err, contents) {
				if (!err) {
					// Output Compressed CSS
					res.writeHead(200, {'Content-Type': 'text/css'})
					res.end(contents.css)
					// And save for future use
					fs.writeFile(outFile, contents.css)
				} else {
					res.writeHead(500)
					console.dir(err)
				}
			}); else {
				// Compressed File is Up-to-date, Output It
				fs.readFile(outFile, function(err, contents) {
					if (!err) {
						// Output Compressed CSS
						res.writeHead(200, {'Content-Type': 'text/css'})
						res.end(contents)
					} else {
						res.writeHead(500)
						console.dir(err)
					}
				})
			}
			break;
		default:
			// Read the file
			fs.readFile(filePath, function(err, contents) {
				if (!err) {
					// If there were no errors, send the content with the default 200 OK header
					switch (ext) {
					case 'json':
						res.writeHead(200, {'Content-Type': 'application/json'})
						break;
					case 'css':
						res.writeHead(200, {'Content-Type': 'text/css'})
						break;
					case 'js':
						res.writeHead(200, {'Content-Type': 'text/javascript'})
						break;
					case 'html':
					default:
						res.writeHead(200, {'Content-Type': 'text/html'})
					}
					res.end(contents)
				} else {
					res.writeHead(500)
					console.dir(err)
				}
			})
		} else {
			res.writeHead(404, {'Content-Type': 'text/html'})
			res.end()
		}
	})
}).listen(3020)