Self-references cause resolves URLs incorrectly and self-referencing objects cause python infinite stack recursion

[bsmedberg-xometry]

First, thanks for the tool!

I have a JSON schema generated by pydantic. It contains multiple object definitions all in one file. https://pydantic-docs.helpmanual.io/usage/schema/ contains a good example of the generated schema.

This schema references its own object definitions like this:

  "properties": {
    "foo_bar": {
      "$ref": "#/definitions/FooBar"
    },
    "Gender": {
      "$ref": "#/definitions/Gender"
    },

sphinx-json-schema doesn't handle this style of reference, and there are two bugs involved:

• Relative links are resolved relative to the base directory of the file being loaded, rather than the file itself. This is because of the os.path.dirname call at

  sphinx-json-schema/sphinx_json_schema/loader.py

  Line 74 in df5e10b

  os.path.dirname(stream if type(stream) == 'str' else self.file), value

• If I correct this by changing the refs to be "$ref": "./MyFile.json#/definitions/FooBar" then the code causes infinite recursion. This is because it tries to keep parsing the same file over and over again.

I spent a few minutes trying to fix this, got a little stuck and I'm wondering about two things:

• have you considered using URL infrastructure for all resolving? If you pass a base URL of file:///path/to/file then you can use standard URL infrastructure (urllib.parse.urljoin) to resolve URL references, without having to explicitly check for http:
• Have you looked into using an existing ref-resolver library? At a quick glance, jsonschema.RefResolver appears to do a lot of what you need here relatively simply.