lib/utils/fs.js
function fileExists(filename) {
    var d = Promise.defer();

    fs.exists(filename, function(exists) {
        d.resolve(exists);
    });

    return d.promise;
}
function fileExists(filename) {
    var d = Promise.defer();

    fs.exists(filename, function(exists) {
        d.resolve(exists);
    });

    return d.promise;
}
function fileExists ( filename ) { var d = Promise . defer ( ) ; fs . exists ( filename , function ( exists ) { d . resolve ( exists ) ; } ) ; return d . promise ; }
Return a promise resolved with a boolean
Return a promise resolved with a boolean