Uncaught TypeError: Cannot read property 'map' of undefined

[ChrisHonniball]

Receiving: Uncaught TypeError: Cannot read property 'map' of undefined | embedded-records-mixin.js:485 on beta.17 with Ember 1.12.0.

This prevents the model.save() request from being sent to the server.

[ChrisHonniball]

Here is my serializer:

export default DS.RESTSerializer.extend(DS.EmbeddedRecordsMixin, {
  attrs: {
    addresses: { embedded: 'always' },
    phones: { embedded: 'always' },
    emails: { embedded: 'always' },
    notes: { embedded: 'always' },
    reminders: { embedded: 'always' },
    calls: { embedded: 'always' },
    customFields: { embedded: 'always' }
  }
});

[igorT]

Which line causes it? Can you maybe reproduce your error in a JSBin? There is a sample one in the CONTRIBUTING.md

[jakesjews]

This JSBin should replicate the issue. http://jsbin.com/cehelabiqe/4/edit
It looks like the error happens when the response from saving a record with an embedded array doesn't include the array. It doesn't seem to throw the error when using beta-16 in the same situation.

[jkatsnelson]

I think I ran into the same situation, but the error came out like this for me:

https://www.dropbox.com/s/f1qbpy85o3mfw70/Screenshot%202015-05-15%2020.13.09.png?dl=0

[jkatsnelson]

reverting back to beta-16 works like a charm.

[ChrisHonniball]

I'll make a JSBin as soon as I get a chance but mine doesn't even get to the API when I get this error. I'm assuming it's happening for me at serialization.

[ChrisHonniball]

Reverting to beta-16.1 flags a lot of deprecation warnings for your DS.attr calls when using Ember 1.12.0.

[jakesjews]

I was wrong in my previous comment. it looks like it's happening before it sends anything to the server on the save. It could be happening when it tries to serialize a null embedded array.

[igorT]

You really should normalize your embedded payloads and pass back a [] for an empty array, but I do agree we should probably guard here.
cc @wecc

[jakesjews]

I agree. We just had some cases where it was unnoticed and it was kinda hard to find the issue. Maybe an assert would be helpful?

[igorT]

Ping @wecc

[ChrisHonniball]

This seems to have returned in 2.0.1.

[mgharbik]

I am running into the same error when trying to override the serializeBelongsTo. Use Ember 2.0.1 as @ChrisHonniball