Node.js CoffeeScript, Jade, and Stylus compiler (watches filesystem for changes)

watcher.js

var OUTPUT_JS_FILENAME = '../media/partner/js/widgets.js'
var OUTPUT_CSS_FILENAME = '../media/partner/css/widgets.css'
var OUTPUT_HTML_PATH = 'templates'

var fs = require('fs')
var jade = require('jade')
var stylus = require('stylus');
var cs = require('coffee-script');
var watch = require('watch');

var isJade = function(fileName) { return fileName.match(/.jade$/); }
var isCoffeeScript = function(fileName) { return fileName.match(/.coffee$/) }
var isStylus = function(fileName) { return fileName.match(/.styl$/)}
var isCompilable = function(fileName) { 
    return isJade(fileName) || isCoffeeScript(fileName) || isStylus(fileName);
}

var allJadeFileNames = [];
var allCoffeeScriptFileNames = [];
var allStylusFileNames = [];

watch.createMonitor('.', { filter: isCompilable }, function (monitor) {
    
    // build list of all the files we care about
    for (fileName in monitor.files) {        
        if (isJade(fileName)) { 
            allJadeFileNames.push(fileName);
        } else if (isCoffeeScript(fileName)) {
            allCoffeeScriptFileNames.push(fileName);
        } else if (isStylus(fileName)) {
            allStylusFileNames.push(fileName);
        }
    }

    // build all on startup
    compileCoffeeScript();
    compileStylus();

    for (var i = 0; i < allJadeFileNames.length; i++) {
        compileJade(allJadeFileNames[i]);
    }

    monitor.on("created", function (f, stat) {
        console.log('created file', f);
        if (isCompilable(f)) compile(f);
    })

    monitor.on("changed", function (f, curr, prev) {
        console.log('changed file', f);
        if (isCompilable(f)) compile(f);
    });

    monitor.on("removed", function (f, stat) {
        console.log('removed file', f);
        if (isCompilable(f)) compile(f);
    });    
});

compile = function(fileName) {
    if (isCoffeeScript(fileName)) {
        compileCoffeeScript();
    } else if (isJade(fileName)) {
        compileJade(fileName);
    } else if (isStylus(fileName)) {
        compileStylus();
    }
}

outputLines = function(e, allCoffeeScript) {
    var line = e.message.match(/line ([0-9]+):/);

    if (line) {
        line = parseInt(line[1]);
        var lines = allCoffeeScript.split('\n');
        for (var i = Math.max(line - 10, 0); i < Math.min(line + 10, lines.length); i++) {
        console.log(i + ": " + lines[i]);
      }
    } 
}

compileCoffeeScript = function() {
    console.log("Compiling CoffeeScript");

    var allCoffeeScript = '';

    for (var i = 0; i < allCoffeeScriptFileNames.length; i++) {
        var fileName = allCoffeeScriptFileNames[i]
        console.log("Reading: " + fileName);
        allCoffeeScript += '\n' + fs.readFileSync(fileName, 'utf8');    
    }

    try {
        var js = cs.compile(allCoffeeScript);
        fs.writeFile(OUTPUT_JS_FILENAME, js);
        console.log(" -> " + OUTPUT_JS_FILENAME);
    } catch (e) { 
        console.log(e); 
        outputLines(e, allCoffeeScript);
    }    
}

// bug: no need to compile child templates...?
compileJade = function(fileName) {
    console.log("Compiling Jade: " + fileName);
    var outputFileName = OUTPUT_HTML_PATH + '/' + fileName.replace('.jade', '.html');

    j = fs.readFileSync(fileName, 'utf8'); 
    
    var html = jade.compile(j, {
        pretty:true, 
        filename: fileName
    })();


    fs.writeFile(outputFileName, html);
    console.log(" -> " + outputFileName);
}

compileStylus = function() {
    console.log("Compiling Stylus");

    var allStylus = '';

    for (var i = 0; i < allStylusFileNames.length; i++) {
        allStylus += fs.readFileSync(allStylusFileNames[i], 'utf8');
    }

    stylus.render(allStylus, {}, 
        function(err, css) { 
           fs.writeFile(OUTPUT_CSS_FILENAME, css); 
           console.log(" -> " + OUTPUT_CSS_FILENAME);
        }
    );   
}