Bundled schema and $id

[paulwib]

It seems that when bundling a schema $id attributes aren't considered which makes the output incompatible with other JSON Schema tools, for example:

a.json:

{
  "$id": "https://schema.example.com/a.json",
  "b": {
    "$ref": "b.json"
  }
}

b.json:

{
  "$id": "https://schema.example.com/b.json",
  "properties": {
    "bar": {
      "$ref": "#/definitions/thing"
    }
  },
  "definitions": {
    "thing": {
      "type": "string"
    }
  }
}

Some code:

const RefParse = require('json-schema-ref-parser');

RefParse.bundle('a.json')
  .then(s => {
    console.log(JSON.stringify(s, null, 2));
  });

Outputs:

{
  "$id": "https://schema.example.com/a.json",
  "b": {
    "$id": "https://schema.example.com/b.json",
    "properties": {
      "bar": {
        "$ref": "#/b/definitions/thing"
      }
    },
    "definitions": {
      "thing": {
        "type": "string"
      }
    }
  }
}

The issue is that in JSON Schema b.properties.bar.$ref is resolved against the nested b.$id giving https://schema.example.com/b.json#/b/definitions/bar which doesn't actually exist.

This breaks other tools, like trying to use the bundled schema in Ajv.

I saw the comment on #22 that the aims of this library do not include supporting JSON Schema and the $id keyword, but it's confusing as the first line of the README says: "Parse, Resolve, and Dereference JSON Schema $ref pointers" 😄 Latest JSON Schema has it's own definition of $ref and no longer uses the expired JSON Reference spec 😮

Any chance of an option to consider $id when bundling?

[JamesMessinger]

Hi @paulwib - Thanks for opening this issue. As you pointed out, I've said before that this library is an implementation of the JSON Reference specification and the JSON Pointer specification, not the JSON Schema specification. Thus, the id keyword isn't supported, because that's not part of JSON Reference or JSON Pointer.

That said... the name of this library is (perhaps inappropriately) json-schema-ref-parser, so it's easy to see why many people have been confused by its lack of support for the JSON Schema spec. So, yeah, I will probably end up adding support for id and $id at some point, to eliminate the confusion and because multiple people have now requested it.

No promises on timeframe though. I have lots of other obligations competing for my time and attention, and this change is likely to be pretty complicated and require a lot of thought and thorough testing.

[JamesMessinger]

Linking #22 and #95 here, for future reference

[philsturgeon]

Also related to #145.

[philsturgeon]

Let's leave #145 to handle this topic.