[STYLE] Fix string capitalization

After chatting with @pcambra, we realized that the problem is that JSON API is not throwing an error if the relationship object is not correctly formatted.

A relationship object contains one or more resource linkage objects. Those in turn contain a resource identifier object, that states that type and id are both mandatory.

We should throw an error if the incoming relationship is not spec compliant.

I looked at the patch and it seems like it's quite outdated and cannot be applied to the latest codebase.
However, type check is already in the module based on the following code:

// ./src/Normalizer/JsonApiDocumentTopLevelNormalizer.php
$relationships = array_map(function ($relationship) {
        if (empty($relationship['data'])) {
          return [];
        }       
        $id_list = array_column($relationship['data'], 'id');
        if (empty($relationship['data'][0]['type'])) {
          throw new BadRequestHttpException("No type specified for related resource");
        }
// ...

So, I just added id check in the patch. If it's not necessary to throw an error on empty id, I'd suggest to claim this issue as fixed if no objections.

Thanks @sergesemashko. Sorry I missed you on DrupalCon, when I came back to say bye you were already gone.

Kicking testbot.

Fixed.

Thank you all!

+++ b/src/Normalizer/JsonApiDocumentTopLevelNormalizer.php
@@ -90,6 +90,9 @@ class JsonApiDocumentTopLevelNormalizer extends NormalizerBase implements Denorm
+          throw new BadRequestHttpException("No id specified for related resource");

Nit: s/id/ID/

Attaching patch with string capitalization changes as per comment.

@RajeevK for some reason the patch is failing to apply. Can you re-roll it?

Attaching another patch.

Re-rolling patch again after created from fresh instance.

Thanks @RajeevK!