jsonschema 4.4.0 RefResolver reproduction

common.schema.json

{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "definitions": {
        "shared-def": {
            "type": "string",
            "pattern": "^shared-"
        }
    }
}

example.json

{
    "a": "local-a",
    "b": "shared-b"
}

example.schema.json

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "definitions": {
    "local-def": {
      "type": "string",
      "pattern": "^local-"
    }
  },
  "properties": {
    "a": {
      "$ref": "#/definitions/local-def"
    },
    "b": {
      "$ref": "common.schema.json#/definitions/shared-def"
    }
  }
}

example_mod.schema.json

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "definitions": {
    "local-def": {
      "type": "string",
      "pattern": "^local-"
    }
  },
  "properties": {
    "a": {
      "$ref": "example.schema.json#/definitions/local-def"
    },
    "b": {
      "$ref": "common.schema.json#/definitions/shared-def"
    }
  }
}

requirements.txt

jsonschema==4.4.0

test.py

from pathlib import Path
import json

import jsonschema

schema_files = [
    Path(__file__).resolve().parent.joinpath('example.schema.json'), # _should_ work
    Path(__file__).resolve().parent.joinpath('example_mod.schema.json') # workaround
]
json_file = Path(__file__).resolve().parent.joinpath('example.json')


def validator_of(base_uri: str):
    schema = json.loads(schema_file.read_text())
    ref_resolver = jsonschema.RefResolver(base_uri, None)
    validator_class = jsonschema.validators.validator_for(schema)
    validator_class.check_schema(schema)  # surprisingly, all green! $ref resolver not applied?
    return validator_class(schema, resolver=ref_resolver)


for schema_file in schema_files:
    print(schema_file)

    base_uri_attempts = [
        f"{schema_file.parent.absolute().as_uri()}", # should work
        f"{schema_file.absolute().as_uri()}", # workaround A
        f"{schema_file.parent.absolute().as_uri()}/", # workaround B
    ]

    for base_uri in base_uri_attempts:
        validator = validator_of(base_uri=base_uri)
        try:
            validator.validate(json.loads(json_file.read_text()))
            print(f"\t✔️\t{base_uri}")
        except BaseException as e:
            print(f"\t❌\t{base_uri}")
            print(f"\t\t{e}")

    print("")

--> python-jsonschema/jsonschema#915 and python-jsonschema/jsonschema#916