Python jsonschema validation always succeeds

Question

I am trying to migrate an application away from jsonschema.RefResolver, due to these deprecation messages when testing:

jsonschema.RefResolver is deprecated 
as of v4.18.0, in favor of the https://github.com/python-jsonschema/referencing library

Here is an example of the current code:

investigation_schema_path=os.path.join(
 BASE_DIR, "..", "resources", "schemas", base_schemas_dir, "core", "investigation_schema.json"
)
with open(investigation_schema_path) as fp
 investigation_schema = json.load(fp)
 # Code below is uses the deprecated jsonschema.RefResolver
 resolver = RefResolver("file://" + investigation_schema_path, investigation_schema)
 validator = Draft4Validator(investigation_schema, resolver=resolver)
 validator.validate(json_to_validate)

The code above validates all test data correctly.

Based on reading https://python-jsonschema.readthedocs.io/en/latest/referencing/ I have replaced the deprecated code with:

 schema = Resource.from_contents(investigation_schema)
 registry = schema @ Registry()
 validator = Draft4Validator(schema, registry)
 validator.validate(json_to_validate)

The result of this is that any test which should detect incorrect json_to_validate fails as no errors are reported: {'errors': [], 'warnings': [], 'validation_finished': True}

The tests which parse correct json_to_validate still appear to pass.

Presumably I have misunderstood how to use the new referencing library. Does anyone have any suggestions?

• John Gordon: We need to see a complete code example including all required inputs (schema and json) and the expected output.

Answer 1

With a bit of trial and (lack of expected) error, it turns out that this syntax will cause validation to happen correctly:

with open(schema_path) as fp:
 schema = json.load(fp)
 validator = Draft4Validator(schema)
 validator.validate(json_in_need_of_validation)