challange.js

function fullName (firstName, secondName) {
  return firstName + ' ' + secondName;
}

function fullName2(obj) {
  return obj.firstName + ' ' + obj.secondName;
}

console.log(beepboop(fullName2, ['firstName', 'secondName'])('David', 'Hipsterson'));
console.log(fullName('David', 'Hipsterson'));

function beepboop (fn, argNames) {
  var functionBody = [
    'var obj = {};'
  ].concat(argNames.map(function (argName, index) {
    return 'obj["' + argName + '"] = arguments[' + index + ']';
  }).concat([
    'return (' + fn.toString() + ')(obj)'
  ])).join('\n');

  console.log(functionBody);

  return new Function (argNames, functionBody);
}