feat(taps): A new schema_is_valid built-in tap test validates stream schemas against the JSON Schema specification

singer_sdk/plugin_base.py

@@ -13,7 +13,6 @@
 from types import MappingProxyType
 
 import click
-from jsonschema import Draft7Validator
 
 from singer_sdk import about, metrics
 from singer_sdk.cli import plugin_cli
@@ -32,11 +31,14 @@
     PluginCapabilities,
 )
 from singer_sdk.mapper import PluginMapper
-from singer_sdk.typing import extend_validator_with_defaults
+from singer_sdk.typing import (
+    DEFAULT_JSONSCHEMA_VALIDATOR,
+    extend_validator_with_defaults,
+)
 
 SDK_PACKAGE_NAME = "singer_sdk"
 
-JSONSchemaValidator = extend_validator_with_defaults(Draft7Validator)
+JSONSchemaValidator = extend_validator_with_defaults(DEFAULT_JSONSCHEMA_VALIDATOR)
 
 
 class MapperNotInitialized(Exception):

singer_sdk/sinks/core.py

@@ -14,6 +14,7 @@
 from types import MappingProxyType
 
 import jsonschema
+import jsonschema.validators
 from typing_extensions import override
 
 from singer_sdk._singerlib.json import deserialize_json
@@ -38,6 +39,7 @@
     get_datelike_property_type,
     handle_invalid_timestamp_in_record,
 )
+from singer_sdk.typing import DEFAULT_JSONSCHEMA_VALIDATOR
 
 if t.TYPE_CHECKING:
     from logging import Logger
@@ -88,7 +90,10 @@ def __init__(
         Raises:
             InvalidJSONSchema: If the schema provided from tap or mapper is invalid.
         """
-        jsonschema_validator = jsonschema.Draft7Validator
+        jsonschema_validator = jsonschema.validators.validator_for(
+            schema,
+            DEFAULT_JSONSCHEMA_VALIDATOR,
+        )
 
         super().__init__(schema)
         if validate_formats:

singer_sdk/testing/suites.py

@@ -17,6 +17,7 @@
     StreamRecordMatchesStreamSchema,
     StreamRecordSchemaMatchesCatalogTest,
     StreamReturnsRecordTest,
+    StreamSchemaIsValidTest,
     TapCLIPrintsTest,
     TapDiscoveryTest,
     TapStreamConnectionTest,
@@ -72,6 +73,7 @@ class TestSuite(t.Generic[T]):
         StreamRecordMatchesStreamSchema,
         StreamRecordSchemaMatchesCatalogTest,
         StreamReturnsRecordTest,
+        StreamSchemaIsValidTest,
         StreamPrimaryKeysTest,
     ],
 )

singer_sdk/testing/tap_tests.py

@@ -5,11 +5,13 @@
 import typing as t
 import warnings
 
-from jsonschema import Draft7Validator
+from jsonschema import validators
+from jsonschema.exceptions import SchemaError
 
 import singer_sdk.helpers._typing as th
 from singer_sdk import Tap
 from singer_sdk.helpers._compat import datetime_fromisoformat
+from singer_sdk.typing import DEFAULT_JSONSCHEMA_VALIDATOR
 
 from .templates import AttributeTestTemplate, StreamTestTemplate, TapTestTemplate
 
@@ -71,6 +73,28 @@ def test(self) -> None:
         assert "progress_markers" not in final_state, self.message
 
 
+class StreamSchemaIsValidTest(StreamTestTemplate):
+    """Test that a stream's schema is valid."""
+
+    name = "schema_is_valid"
+
+    def test(self) -> None:
+        """Run test.
+
+        Raises:
+            AssertionError: if schema is not valid.
+        """
+        schema = self.stream.schema
+        default = DEFAULT_JSONSCHEMA_VALIDATOR
+        validator = validators.validator_for(schema, default=default)
+
+        try:
+            validator.check_schema(schema)
+        except SchemaError as e:  # pragma: no cover
+            msg = f"Schema is not valid: {e}"
+            raise AssertionError(msg) from e
+
+
 class StreamReturnsRecordTest(StreamTestTemplate):
     """Test that a stream sync returns at least 1 record."""
 
@@ -134,10 +158,10 @@ class StreamRecordMatchesStreamSchema(StreamTestTemplate):
     def test(self) -> None:
         """Run test."""
         schema = self.stream.schema
-        validator = Draft7Validator(
-            schema,
-            format_checker=Draft7Validator.FORMAT_CHECKER,
-        )
+        default = DEFAULT_JSONSCHEMA_VALIDATOR
+        validator = validators.validator_for(schema, default=default)(schema)
+        validator.format_checker = default.FORMAT_CHECKER
+
         for record in self.stream_records:
             errors = list(validator.iter_errors(record))
             error_messages = "\n".join(

singer_sdk/typing.py

@@ -58,9 +58,6 @@
 import sqlalchemy as sa
 from jsonschema import ValidationError, validators
 
-if t.TYPE_CHECKING:
-    from jsonschema.protocols import Validator
-
 from singer_sdk.helpers._typing import (
     JSONSCHEMA_ANNOTATION_SECRET,
     JSONSCHEMA_ANNOTATION_WRITEONLY,
@@ -71,13 +68,16 @@
 if t.TYPE_CHECKING:
     import sys
 
+    from jsonschema.protocols import Validator
+
     if sys.version_info >= (3, 10):
         from typing import TypeAlias  # noqa: ICN003
     else:
         from typing_extensions import TypeAlias
 
 
 __all__ = [
+    "DEFAULT_JSONSCHEMA_VALIDATOR",
     "ArrayType",
     "BooleanType",
     "CustomType",
@@ -118,11 +118,13 @@
     None,
 ]
 
+DEFAULT_JSONSCHEMA_VALIDATOR: type[Validator] = validators.Draft7Validator  # type: ignore[assignment]
+
 T = t.TypeVar("T", bound=_JsonValue)
 P = t.TypeVar("P")
 
 
-def extend_validator_with_defaults(validator_class):  # noqa: ANN001, ANN201
+def extend_validator_with_defaults(validator_class: type[Validator]):  # noqa: ANN201
     """Fill in defaults, before validating with the provided JSON Schema Validator.
 
     See

tests/core/sinks/test_validation.py

@@ -121,8 +121,8 @@ def test_validate_fastjsonschema():
 
 
 @pytest.fixture
-def draft7_sink_stop():
-    """Return a sink object with Draft7 checks enabled."""
+def default_draft_sink_stop():
+    """Return a sink object with the default draft checks enabled."""
 
     class CustomSink(BatchSinkMock):
         """Custom sink class."""
@@ -147,8 +147,8 @@ class CustomSink(BatchSinkMock):
 
 
 @pytest.fixture
-def draft7_sink_continue():
-    """Return a sink object with Draft7 checks enabled."""
+def default_draft_sink_continue():
+    """Return a sink object with the default draft checks enabled."""
 
     class CustomSink(BatchSinkMock):
         """Custom sink class."""
@@ -174,9 +174,9 @@ class CustomSink(BatchSinkMock):
 
 
 def test_validate_record_jsonschema_format_checking_enabled_stop_on_error(
-    draft7_sink_stop,
+    default_draft_sink_stop,
 ):
-    sink: BatchSinkMock = draft7_sink_stop
+    sink: BatchSinkMock = default_draft_sink_stop
 
     record = {
         "id": 1,
@@ -195,9 +195,9 @@ def test_validate_record_jsonschema_format_checking_enabled_stop_on_error(
 
 def test_validate_record_jsonschema_format_checking_enabled_continue_on_error(
     capsys: pytest.CaptureFixture,
-    draft7_sink_continue,
+    default_draft_sink_continue,
 ):
-    sink: BatchSinkMock = draft7_sink_continue
+    sink: BatchSinkMock = default_draft_sink_continue
 
     record = {
         "id": 1,

tests/core/test_jsonschema_helpers.py

@@ -8,7 +8,6 @@
 from textwrap import dedent
 
 import pytest
-from jsonschema import Draft6Validator
 
 from singer_sdk.helpers._typing import (
     JSONSCHEMA_ANNOTATION_SECRET,
@@ -27,6 +26,7 @@
 )
 from singer_sdk.tap_base import Tap
 from singer_sdk.typing import (
+    DEFAULT_JSONSCHEMA_VALIDATOR,
     AllOf,
     AnyType,
     ArrayType,
@@ -932,7 +932,7 @@ def test_discriminated_union():
         ),
     )
 
-    validator = Draft6Validator(th.to_dict())
+    validator = DEFAULT_JSONSCHEMA_VALIDATOR(th.to_dict())
 
     assert validator.is_valid(
         {