confirming prebuilt usage via a test

Author: sydney-runkle

tests/validators/test_prebuilt.py

@@ -0,0 +1,48 @@
+from pydantic_core import SchemaSerializer, SchemaValidator, core_schema
+
+
+def test_prebuilt_val_and_ser_used() -> None:
+    class InnerModel:
+        x: int
+
+    inner_schema = core_schema.model_schema(
+        InnerModel,
+        schema=core_schema.model_fields_schema(
+            {'x': core_schema.model_field(schema=core_schema.int_schema())},
+        ),
+    )
+
+    inner_schema_validator = SchemaValidator(inner_schema)
+    inner_schema_serializer = SchemaSerializer(inner_schema)
+    InnerModel.__pydantic_complete__ = True  # pyright: ignore[reportAttributeAccessIssue]
+    InnerModel.__pydantic_validator__ = inner_schema_validator  # pyright: ignore[reportAttributeAccessIssue]
+    InnerModel.__pydantic_serializer__ = inner_schema_serializer  # pyright: ignore[reportAttributeAccessIssue]
+
+    class OuterModel:
+        inner: InnerModel
+
+    outer_schema = core_schema.model_schema(
+        OuterModel,
+        schema=core_schema.model_fields_schema(
+            {
+                'inner': core_schema.model_field(
+                    schema=core_schema.model_schema(
+                        InnerModel,
+                        schema=core_schema.model_fields_schema(
+                            # note, we use str schema here even though that's incorrect
+                            # in order to verify that the prebuilt validator is used
+                            # off of InnerModel with the correct int schema, not this str schema
+                            {'x': core_schema.model_field(schema=core_schema.str_schema())},
+                        ),
+                    )
+                )
+            }
+        ),
+    )
+
+    outer_validator = SchemaValidator(outer_schema)
+    outer_serializer = SchemaSerializer(outer_schema)
+
+    result = outer_validator.validate_python({'inner': {'x': 1}})
+    assert result.inner.x == 1
+    assert outer_serializer.to_python(result) == {'inner': {'x': 1}}