Promise aware node.js repl

promise-repl.js

var vm = require('vm');
function fancyPromiseEval(code, context, file, cb) {
  var err, result, script;
  // first, create the Script object to check the syntax
  try {
    script = vm.createScript(code, {
      filename: file,
      displayErrors: false
    });
  } catch (e) {
    return cb(e);
  }

  if (!err) {
    try {
      result = script.runInContext(context, { displayErrors: false });
    } catch (e) {
      return cb(e);
    }
  }

  if (result && typeof result.nodeify === 'function') {
    result.nodeify(cb);
  } else {
    cb(null, result);
  }
}

var repl = require('repl').start({
  eval: fancyPromiseEval
});