Jakefile.js

var // Dependency References
		fs = require( "fs" ),
		_ = require( "underscore" ),
		jshint = require( "jshint" ).JSHINT,
		colors = require( "colors" ),
		uglifyjs = require( "uglify-js" ),
		Buffer = require( "buffer" ).Buffer,
		zlib = require( "zlib" ),
		dateFormat = require( "dateformat" ),
		stats = require( "stats" ),
		cp = require("child_process"),
		exec = cp.exec,
		spawn = cp.spawn,
		assert = require( "assert" ),
		child;

var // Shortcut References
		slice = Array.prototype.slice,
		now = new Date();

var // Program References
		$$ = {},
		// Get options, defaults merged with build.json file.
		config = _.extend({}, true, {

				// Meta Build Info
				"meta": {
					"buildDate": dateFormat( now, "m/d/yyyy" )
				},

				// Overridden with build.json
				"files": {},

				// License Banner Template
				"banner": [
					"// <%= label %> - v<%= version %> - <%= buildDate %>",
					"// <%= homeurl %>",
					"// <%= copyright %>; Licensed <%= license.join(', ') %>"
				].join( "\n" ),

				// JSHint Optional Settings
				"jshint": {
					unused: true,
					unuseds: true,
					devel: true,
					undef: true,
					noempty: true,
					evil: true,
					forin: false,
					maxerr: 100,
					eqnull: true
					// "curly": true,
					// "eqnull": true,
					// "immed": true,
					// "newcap": true,
					// "noarg": true,
					// "undef": true,
					// "browser": true,
					// "predef": [ "jQuery" ]
				},

				// Uglify Optional Settings
				"uglify": {
					"mangle": {
						"except": [ "$" ]
					},
					"squeeze": {},
					"codegen": {}
				}
			},
			readJson( "build.json", true )
		),
		// Setup Distribution File Banner (License Block)
		banner = _.template( typeof config.banner == "string" ? config.banner : "" );

// Logging Utility Functions
function header( msg ) {
	writeln( "\n" + msg.underline );
}
function write( msg ) {
	process.stdout.write( (msg != null && msg) || "" );
}
function writeln( msg ) {
	console.log( (msg != null && msg) || "" );
}
function ok( msg ) {
	writeln( msg ? "\n>> ".green + msg : "OK".green );
}
function error( msg ) {
	writeln( msg ? "\n>> ".red + msg : "ERROR".red );
}


// Read a file.
function readFile( filepath ) {
	var src;
	write( "Reading " + filepath + "..." );
	try {
		src = fs.readFileSync( filepath, "UTF-8" );
		ok();
		return src;
	} catch( e ) {
		error();
		fail( e.message );
	}
}

// Write a file.
function writeFile( filepath, contents, silent ) {
	// if ( config.nowrite ) {
	//	 writeln('Not'.underline + ' writing ' + filepath + ' (dry run).');
	//	 return true;
	// }

	if ( arguments.length < 3 ) {
		silent = true;
	}

	silent || write( "Writing " + filepath + "..." );

	try {
		fs.writeFileSync( filepath, contents, "UTF-8" );
	} catch( e ) {
		error();
		fail( e );
	}

	ok();
	return true;
}

// Read and parse a JSON file.
function readJson( filepath, silent ) {
	var result;

	silent || write( "Reading " + filepath + "..." );

	try {
		result = JSON.parse(
			fs.readFileSync( filepath, "UTF-8" )
		);
	} catch( e ) {
		silent || error();
		fail( e.message );
	}

	silent || ok();
	return result;
}


// # Lint some source code.
// From http://jshint.com
function hint( src, path ) {
	write( "Validating with JSHint...");

	if ( jshint( src, config.jshint ) ) {
		ok();
	} else {
		error();

		jshint.errors.forEach(function( e ) {
			if ( !e ) { return; }
			var str = e.evidence ? e.evidence.inverse : "";

			str = str.replace( /\t/g, " " ).trim();
			error( path + " [L" + e.line + ":C" + e.character + "] " + e.reason + "\n  " + str );
		});
		fail( "JSHint found errors." );
	}
}

// # Minify with UglifyJS.
// From https://github.com/mishoo/UglifyJS
function uglify( src ) {
	write( "Uglifying..." );

	var jsp = uglifyjs.parser,
			pro = uglifyjs.uglify,
			ast;

	try {
		ast = jsp.parse( src );
		ast = pro.ast_mangle( ast, config.uglify.mangle || {});
		ast = pro.ast_squeeze( ast, config.uglify.squeeze || {});
		src = pro.gen_code( ast, config.uglify.codegen || {});

	} catch( e ) {
		error();
		error( "[L" + e.line + ":C" + e.col + "] " + e.message + " (position: " + e.pos + ")" );
		fail( e.message );
		return false;
	}

	ok();
	return src;
}

// Return deflated src input.
function gzip( src ) {
	return zlib.deflate( new Buffer( src ) );
}

// Jake Tasks

desc( "Hint & Minify" );
task( "default", [ "hint", "min" ], function() {
	// Nothing
});

desc( "Validate with JSHint." );
task( "hint", function() {

	header( "Validating with JSHint" );

	_.keys( config.files ).forEach(function( minpath ) {

		var files = config.files[ minpath ],
				concat = files.src.map(function( path ) {
					var src = readFile( path );

					config.jshint.devel = config.jshint.debug = files.debug;

					if ( files.prehint ) {
						hint( src, path );
					}

					return src;
				}).join( "\n" );

		if ( files.src.length ) {
			write( "Hinting concatenated source: " + files.src.length + " scripts..." );
			ok();
			if ( files.posthint ) {
				hint( concat, "post" );
			}
		}
	});
});

desc( "Minify with Uglify-js." );
task( "min", function() {

	header( "Minifying with Uglify-js" );

	_.keys( config.files ).forEach(function( minpath ) {

		var file = config.files[ minpath ],
				concat = file.src.map( function( path ) {
					return readFile( path );
				}).join( "\n" ),

				intro, fullpath, min;


		fullpath = minpath + ".js";
		minpath = minpath + ".min.js"

		// Generate intro block with banner template,
		// Inject meta build data
		intro = banner( _.extend( file.meta, config.meta ) );

		// Without a newline, the min source code will run on the same
		// Line as the intro lic/banner block
		if ( intro ) {
			intro += "\n";
		}

		// Provide information about current file being built
		if ( file.src.length ) {
			write( "Concatenating " + file.src.length + " script(s)" );
			ok();
		}

		// Write full sized, concatenated source
		writeFile( fullpath, concat, false );

		// Minify/Uglify and Write compressed, concatenated source
		if ( min = uglify( concat ) ) {

			min = intro + min;

			if ( writeFile( minpath, min, false ) ) {
				ok( "Compressed size: " + (gzip( min ).length + "").yellow + " bytes gzipped (" + ( min.length + "" ).yellow + " bytes minified)." );
			}
		}
	});
});

desc( "View static analysis of JavaScript program code" );
task( "stats", [], function() {

	header( "Statistics" );

	var exts = [ ".js", ".min.js" ],
		comp, stat, diff, color;

	_.keys( config.files ).forEach(function( file ) {

		exts.forEach(function( ext ) {

			stat = stats.parse( readFile( file + ext ) );

			_.keys( stat ).forEach( function( key, idx ) {

				write( "    " + key + ": " + this[ key ] );

				if ( comp ) {
					diff = (comp[ key ] - this[ key ]);

					color = Math.abs(diff) > 0 ? "red" : "grey";

					write( " (-" + (diff + "")[ color ] + ")" );
				}

				write( "\n" );
			}, stat );

			if ( comp == null ) {
				comp = stat;
			}

		});
	});
});