rf: Isolate validation-specific dependencies

tools/schemacode/bidsschematools/schema.py

@@ -10,8 +10,6 @@
 from copy import deepcopy
 from functools import lru_cache
 
-from jsonschema import ValidationError, validate
-
 if sys.version_info < (3, 9):
     from importlib_resources import files
 else:
@@ -288,13 +286,24 @@ def filter_schema(schema, **kwargs):
 
 def validate_schema(schema: Namespace):
     """Validate a schema against the BIDS metaschema."""
+    import httpx
+    import jsonschema
+    from referencing import Registry, Resource
+
+    registry: Registry = Registry(
+        retrieve=lambda uri: Resource.from_contents(httpx.get(uri).json())
+    )  # type: ignore[call-arg]  # Unclear why type inference fails here
+
     metaschema = json.loads(files("bidsschematools.data").joinpath("metaschema.json").read_text())
 
+    validator_class = jsonschema.validators.validator_for(metaschema)
+    validator = validator_class(metaschema, registry=registry)
+
     # validate is put in this try/except clause because the error is sometimes too long to
     # print in the terminal
     try:
-        validate(instance=schema.to_dict(), schema=metaschema)
-    except ValidationError as e:
+        validator.validate(schema.to_dict())
+    except jsonschema.ValidationError as e:
         with tempfile.NamedTemporaryFile(
             prefix="schema_error_", suffix=".txt", delete=False, mode="w+"
         ) as file:

tools/schemacode/bidsschematools/tests/test_schema.py

@@ -382,5 +382,4 @@ def test_invalid_value():
     ]["density"] = "invalid"
     with pytest.raises(ValidationError) as e:
         schema.validate_schema(namespace)
-    print(e.value)
     assert "invalid" in str(e.value)

tools/schemacode/setup.cfg

@@ -24,7 +24,6 @@ install_requires =
     click
     pyyaml
     importlib_resources; python_version < "3.9"
-    jsonschema
 packages = find:
 include_package_data = false
 zip_safe = false
@@ -37,6 +36,9 @@ render =
     tabulate
     pandas
     markdown-it-py
+validation =
+    jsonschema
+    httpx
 expressions =
     pyparsing
 tests =
@@ -47,11 +49,10 @@ tests =
     flake8-isort
     pytest
     pytest-cov
+    bidsschematools[render,validation,expressions]
 all =
     %(doc)s
-    %(render)s
     %(tests)s
-    %(expressions)s
 
 [options.package_data]
 bidsschematools =