Ensure that a directory exists (and create it if it doesn't)

ensureDirectoryExists.js

function ensureDirectoryExists( path, fn ) {
	fs.exists( path, function( exists ) {
		if( exists ) {
			fn();
		} else {
			var parent = path.replace( /(\/|\\)[^\/\\]+$/, '' );
			ensureDirectoryExists( parent, function() {
				fs.mkdir( path, fn );
			});
		}
	});
}