require('function-at');

function thenable(name) {
  if (!name) return Promise.reject(
    new TypeError('name string required'));
  var greeting = 'Hello, ' + name + '!';
  return Promise.resolve(greeting);
}

// Normal callback
function callback(error, result) {
  console.log('calback ---------------');
  console.log('  error:', error);
  console.log('  result:', result);
}

thenable('Friday')
  // On fulfillment 
  // set error to null
  .then(callback.atfirst(null))

// Given the thenable() and callback()
// functions definitions...

thenable() 
  // On rejection 
  // set result to empty string
  .catch(callback.atlast(''));