How to use ES6 generators with Hapi.js <3

gistfile1.js

import co from 'co'

// Generator controller,
// this.models refers to Sequelize models added with server.bind()
function* loginController(request) {

  let user = yield this.models.User.find({
    where: {
      email: request.payload.email
    }
  });

  if (!user)
    yield Promise.reject(Boom.notFound('USER_NOT_FOUND'));
    
  return user.toJSON();

}

// Wraps generator so it can be used in Hapi responses
function wrapGen(generator) {
  let handler = co.wrap(generator);
  return function(request, reply) {
    handler.bind(this)(request, reply)
      .then(reply)
      .catch(reply);
  };
}

// Here's the most typical Hapi.js route 
server.route({
    method: 'POST',
    path: '/auth/login',
    handler: wrapGen(loginController)
});

With newer co versions the wrapping is even easier.

Just use

import co from 'co';

// Wraps generator so it can be used in Hapi Route Handlers
function generoute(generator) {
  return co.wrap(generator);
}

export default generoute;

This allows to use a generator handler with request and reply.

function* myHandler (request, reply) {
  try {
    let user =  yield DB.getUser(request.params.id);
    ...
    reply(user);
  } catch (e) {
    reply({
       customErrorMessage: 'All your base are belong to us!'
    }).code(400);
  }
}

This allows to set the HTTP response codes, etc.

I wrote small plugin for this: noveogroup-amorgunov/hapi-generoutify