Meteor Promises in Accounts.onCreateUser - meteor

Question

I would like to create a stripe account during the user registration in meteor and adjusted Accounts.onCreateUser for that purpose with a promise.
Accounts.onCreateUser((options, user) => {
if (user.services.facebook) {
const { first_name, last_name, email } = user.services.facebook;
user.profile = {}
user.profile.first_name = first_name
user.profile.last_name = last_name
}
else{
user.profile = options.profile
}
user.stripe = {}
return new Promise((resolve,reject) => {
stripe.customers.create({
description: user.profile.first_name + ' ' + user.profile.last_name
},function(err,response){
if (!err) {
user.stripe.id = response.id
resolve(user);
} else {
reject('Could not create user');
}
});
})
});
While the user gets properly created in stripe, the user document in the meteor mongo database only contains the userid but no other field.
Am I using the promise wrong? Any help would be appreciated!

Answer 1

Because onCreateUser runs on the server, we can wrap the Stripe call in a Fiber using Meteor.wrapAsync.
Fibers allow async code to run as though it was synchronous, but only on the server. (Here's a great presentation on what Fibers are and why Meteor uses them)
With wrapAsync the code looks like this:
Accounts.onCreateUser((options, user) => {
if (user.services.facebook) {
const { first_name, last_name, email } = user.services.facebook;
user.profile = {}
user.profile.first_name = first_name
user.profile.last_name = last_name
} else {
user.profile = options.profile
}
user.stripe = {};
const createStripeCustomer = Meteor.wrapAsync(stripe.customers.create,stripe.customers);
const response = createStripeCustomer({
description: user.profile.first_name + ' ' + user.profile.last_name
});
user.stripe.id = response.id
return user;
});

Answer 2

Yes, you create the promise but you don't wait until it resolves. By the time it does onCreateUser has long returned. Try this:
function createStripeUser(user) {
return new Promise((resolve,reject) => {
stripe.customers.create({
description: user.profile.first_name + ' ' + user.profile.last_name
},function(err,response){
if (!err) {
user.stripe.id = response.id
resolve(user);
} else {
reject(err);
}
});
})
}
Accounts.onCreateUser(async (options, user) => {
if (user.services.facebook) {
const { first_name, last_name, email } = user.services.facebook;
user.profile = {}
user.profile.first_name = first_name
user.profile.last_name = last_name
}
else {
user.profile = options.profile
}
user.stripe = {}
try {
return await createStripeUser(user);
} catch(e) {
// handle your error
}
});