queryRecord throws when the response is empty

[XrXr]

http://emberjs.jsbin.com/fekufi/1/edit?js,console

Error: Assertion Failed: You must include an 'id' for undefined in an object passed to 'push'

If the payload for authors is changed to null, the same error happens.

This use to just resolve with undefined in ED 1.3.x, so I assumed it's a convenience feature.

I asked about this on Slack, the consensus seems to be that the promise should reject like a 404.

[XrXr]

Here is a bin for JSONAPIAdapter

http://emberjs.jsbin.com/fekufi/edit?js,console

SyntaxError: Unexpected end of input
at Object.parse (native)
at x.extend.parseJSON

[sescobb27]

@XrXr http://jsonapi.org/format/#fetching in JSONAPI payload can't be empty. you SHOULD return

{
  "data": []
}

or

{
  "data": null
}

[jherdman]

I ran into this too. The JSON payload is intentionally empty though.

Here's another contrived example: http://emberjs.jsbin.com/sikivanomi/edit?html,js,output. Simply put, my query found nothing on the back end. This was a valid response in ED 1.13, I don't see why my API response wouldn't be valid now.

[sescobb27]

This works as expected

// Returns books embedded in authors
$.mockjax({
  type: 'GET',
  url: '/authors',
  status: '204',
  dataType: 'json',
  responseText: '{"data": []}'
});

[jherdman]

I think the issue is more accurately stated as "queryRecord shits the bed with REST Adapter when empty response returned"

[sescobb27]

@jherdman I think is because you are querying just a record, but you are returning an array (an empty one)

[jherdman]

Indeed, but that's how this jazz works. Peep this:

data/packages/ember-data/lib/serializers/rest-serializer.js

Lines 305 to 327 in 31bf071

	if (isSingle) {
	/*jshint loopfunc:true*/
	data.forEach((resource) => {
	/*
	Figures out if this is the primary record or not.
	It's either:
	1. The record with the same ID as the original request
	2. If it's a newly created record without an ID, the first record
	in the array
	*/
	var isUpdatedRecord = isPrimary && coerceId(resource.id) === id;
	var isFirstCreatedRecord = isPrimary && !id && !documentHash.data;
	if (isFirstCreatedRecord || isUpdatedRecord) {
	documentHash.data = resource;
	} else {
	documentHash.included.push(resource);
	}
	});
	} else {

This is the meat and potatoes of how the REST Adapter goes about figuring out which record to pluck out of a response when you're querying for a record. Indeed the adapter is expecting an array response. The trick seems to be further down in the stack. After this your normalized response look like this: { data: null, included: [] }. The data: null bit causes all sorts of barfage and sadness.

[sescobb27]

but that's because REST adapter serialize plain JSON payload into JSON API compliant payload in order to let ED load it into the store

[wecc]

Seems related to #3790

[pangratz]

I am going to close this issue as the behavior of queryRecord has been overhauled in #4300. Please see that PR for more context but basically returning { data: null } or { data: [] } for a queryRecord using the rest adapter/serializer now resolves the promise with null.

Please note that returning an array for the primary data of a queryRecord is deprecated, as this method should only be used for use cases where a single record is returned. In all other cases query should be used instead.