Header with Json:include is always Hateoas header

Thank you for pointing this out!

Having a header that specifies that the content meets the JSON:API spec when it does not is a bug.

I mistakenly changed the status. I will test this locally.

I looked into this in more detail and it seems that we are not violating the JSON:API spec, which states that the relationships member is optional. So flattening the relationships does not appear to be a violation of the spec. If you still think this is a specification violation, please describe in detail what the violation is.

To show that parsing occurred, when this module parses output, it adds parsed: true like this:

  "jsonapi": {
    "version": "1.0",
    "meta": {
      "links": {
        "self": {
          "href": "http://jsonapi.org/format/1.0/"
        }
      }
    },
    "parsed": true
  },

Hi :)

After seeing the message in this thread/issue
https://www.drupal.org/project/jsonapi_include/issues/3460642#comment-15... ✨ JSON:API Include can break some JSON:API deserializers by not including the attributes or relationships structure Needs review

I'm not entirely sure that we haven’t broken the HATEOAS principles of the JSON:API standard, especially since some keys are required when trying to include data.

Thank you for the response. If you can point to where you think the specification is being violated, I'll consider it.

As for the principle-- well, this module flattens the response; it's basically the only thing the module does. If you don't want your responses flattened, you can just use JSON:API without this module.