Make generic TypeAliasType specifications produce different schema definitions

pydantic/_internal/_core_utils.py

@@ -8,15 +8,15 @@
     Hashable,
     TypeVar,
     Union,
-    _GenericAlias,  # type: ignore
     cast,
 )
 
 from pydantic_core import CoreSchema, core_schema
 from pydantic_core import validate_core_schema as _validate_core_schema
-from typing_extensions import TypeAliasType, TypeGuard, get_args
+from typing_extensions import TypeAliasType, TypeGuard, get_args, get_origin
 
 from . import _repr
+from ._typing_extra import is_generic_alias
 
 AnyFunctionSchema = Union[
     core_schema.AfterValidatorFunctionSchema,
@@ -86,8 +86,9 @@ def get_type_ref(type_: type[Any], args_override: tuple[type[Any], ...] | None =
     This `args_override` argument was added for the purpose of creating valid recursive references
     when creating generic models without needing to create a concrete class.
     """
-    origin = type_
-    args = get_args(type_) if isinstance(type_, _GenericAlias) else (args_override or ())
+    origin = get_origin(type_) or type_
+
+    args = get_args(type_) if is_generic_alias(type_) else (args_override or ())
     generic_metadata = getattr(type_, '__pydantic_generic_metadata__', None)
     if generic_metadata:
         origin = generic_metadata['origin'] or origin

pydantic/_internal/_generate_schema.py

@@ -1052,18 +1052,20 @@ def _type_alias_type_schema(
         self,
         obj: Any,  # TypeAliasType
     ) -> CoreSchema:
-        origin = get_origin(obj)
-        origin = origin or obj
-        with self.defs.get_schema_or_ref(origin) as (ref, maybe_schema):
+        with self.defs.get_schema_or_ref(obj) as (ref, maybe_schema):
             if maybe_schema is not None:
                 return maybe_schema
 
+            origin = get_origin(obj) or obj
+
             namespace = (self._types_namespace or {}).copy()
             new_namespace = {**_typing_extra.get_cls_types_namespace(origin), **namespace}
             annotation = origin.__value__
 
             self._types_namespace = new_namespace
             typevars_map = get_standard_typevars_map(obj)
+
+            annotation = _typing_extra.eval_type_lenient(annotation, self._types_namespace, None)
             annotation = replace_types(annotation, typevars_map)
             schema = self.generate_schema(annotation)
             assert schema['type'] != 'definitions'

pydantic/_internal/_typing_extra.py

@@ -433,3 +433,14 @@ def is_dataclass(_cls: type[Any]) -> TypeGuard[type[StandardDataclass]]:
 
 def origin_is_type_alias_type(origin: Any) -> TypeGuard[TypeAliasType]:
     return isinstance(origin, TypeAliasType)
+
+
+if sys.version_info >= (3, 10):
+
+    def is_generic_alias(type_: type[Any]) -> bool:
+        return isinstance(type_, (types.GenericAlias, typing._GenericAlias))  # type: ignore[attr-defined]
+
+else:
+
+    def is_generic_alias(type_: type[Any]) -> bool:
+        return isinstance(type_, typing._GenericAlias)  # type: ignore

tests/test_type_alias_type.py

@@ -5,7 +5,7 @@
 from annotated_types import MaxLen
 from typing_extensions import Annotated, TypeAliasType
 
-from pydantic import Field, ValidationError
+from pydantic import BaseModel, Field, ValidationError
 from pydantic.type_adapter import TypeAdapter
 
 T = TypeVar('T')
@@ -182,11 +182,11 @@ def test_type_alias_annotated_defs() -> None:
         'type': 'array',
         'minItems': 2,
         'prefixItems': [
-            {'$ref': '#/$defs/MyList_MaxLen_max_length_1_'},
-            {'$ref': '#/$defs/MyList_MaxLen_max_length_1_'},
+            {'$ref': '#/$defs/MyList_int__MaxLen_max_length_1_'},
+            {'$ref': '#/$defs/MyList_int__MaxLen_max_length_1_'},
         ],
         'maxItems': 2,
-        '$defs': {'MyList_MaxLen_max_length_1_': {'type': 'array', 'items': {'type': 'integer'}, 'maxItems': 1}},
+        '$defs': {'MyList_int__MaxLen_max_length_1_': {'type': 'array', 'items': {'type': 'integer'}, 'maxItems': 1}},
     }
 
 
@@ -220,11 +220,11 @@ def test_recursive_generic_type_alias() -> None:
     ]
 
     assert t.json_schema() == {
-        'allOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}],
+        'allOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}],
         '$defs': {
-            'RecursiveGenericAlias': {
+            'RecursiveGenericAlias_int_': {
                 'type': 'array',
-                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}, {'type': 'integer'}]},
+                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}, {'type': 'integer'}]},
             }
         },
     }
@@ -250,12 +250,12 @@ def test_recursive_generic_type_alias_annotated() -> None:
     # insert_assert(t.json_schema())
     assert t.json_schema() == {
         'type': 'array',
-        'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}, {'type': 'integer'}]},
+        'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}, {'type': 'integer'}]},
         'maxItems': 1,
         '$defs': {
-            'RecursiveGenericAlias': {
+            'RecursiveGenericAlias_int_': {
                 'type': 'array',
-                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}, {'type': 'integer'}]},
+                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}, {'type': 'integer'}]},
             }
         },
     }
@@ -284,18 +284,18 @@ def test_recursive_generic_type_alias_annotated_defs() -> None:
         'type': 'array',
         'minItems': 2,
         'prefixItems': [
-            {'$ref': '#/$defs/RecursiveGenericAlias_MaxLen_max_length_1_'},
-            {'$ref': '#/$defs/RecursiveGenericAlias_MaxLen_max_length_1_'},
+            {'$ref': '#/$defs/RecursiveGenericAlias_int__MaxLen_max_length_1_'},
+            {'$ref': '#/$defs/RecursiveGenericAlias_int__MaxLen_max_length_1_'},
         ],
         'maxItems': 2,
         '$defs': {
-            'RecursiveGenericAlias': {
+            'RecursiveGenericAlias_int_': {
                 'type': 'array',
-                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}, {'type': 'integer'}]},
+                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}, {'type': 'integer'}]},
             },
-            'RecursiveGenericAlias_MaxLen_max_length_1_': {
+            'RecursiveGenericAlias_int__MaxLen_max_length_1_': {
                 'type': 'array',
-                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias'}, {'type': 'integer'}]},
+                'items': {'anyOf': [{'$ref': '#/$defs/RecursiveGenericAlias_int_'}, {'type': 'integer'}]},
                 'maxItems': 1,
             },
         },
@@ -314,3 +314,26 @@ def test_field() -> None:
         'allOf': [{'$ref': '#/$defs/SomeAlias'}],
         'title': 'abc',
     }
+
+
+def test_nested_generic_type_alias_type() -> None:
+    class MyModel(BaseModel):
+        field_1: MyList[bool]
+        field_2: MyList[str]
+
+    model = MyModel(field_1=[True], field_2=['abc'])
+
+    assert model.model_json_schema() == {
+        '$defs': {
+            'MyList_bool_': {'items': {'type': 'boolean'}, 'type': 'array'},
+            'MyList_str_': {'items': {'type': 'string'}, 'type': 'array'},
+        },
+        'properties': {'field_1': {'$ref': '#/$defs/MyList_bool_'}, 'field_2': {'$ref': '#/$defs/MyList_str_'}},
+        'required': ['field_1', 'field_2'],
+        'title': 'MyModel',
+        'type': 'object',
+    }
+
+
+def test_non_specified_generic_type_alias_type() -> None:
+    assert TypeAdapter(MyList).json_schema() == {'items': {}, 'type': 'array'}