Fix typeddict issue with generics

src/quart_schema/conversion.py

@@ -3,7 +3,7 @@
 import sys
 from dataclasses import fields, is_dataclass
 from inspect import isclass
-from typing import Any, Literal, TypeGuard, TypeVar
+from typing import Any, get_origin, Literal, TypeGuard, TypeVar
 
 import humps
 from quart import current_app
@@ -255,31 +255,36 @@ def _is_list_or_dict(type_: type) -> bool:
     return origin in (dict, dict, list, list)
 
 
+def _valid_model_class(model_class: type) -> bool:
+    """Validate if a type can be used as a schema class.
+
+    Returns True for types that don't require conversion:
+    - TypedDict, dataclasses, and attrs classes
+    - Built-in dict/list and their generic aliases (e.g., dict[str, int])
+    """
+    if (
+        _is_list_or_dict(model_class)
+        or is_dataclass(model_class)
+        or is_typeddict(model_class)
+        # Generic aliases: https://github.com/python/cpython/issues/149574
+        or is_dataclass(get_origin(model_class))
+        or is_typeddict(get_origin(model_class))
+    ):
+        return True
+    return False
+
+
 def _use_pydantic(model_class: type, preference: str | None) -> bool:
     return PYDANTIC_INSTALLED and (
         is_pydantic_dataclass(model_class)
         or (isclass(model_class) and issubclass(model_class, BaseModel))
-        or (
-            (
-                _is_list_or_dict(model_class)
-                or is_dataclass(model_class)
-                or is_typeddict(model_class)
-            )
-            and preference != "msgspec"
-        )
+        or (_valid_model_class(model_class) and preference != "msgspec")
     )
 
 
 def _use_msgspec(model_class: type, preference: str | None) -> bool:
     return MSGSPEC_INSTALLED and (
         (isclass(model_class) and issubclass(model_class, Struct))
         or is_attrs(model_class)
-        or (
-            (
-                _is_list_or_dict(model_class)
-                or is_dataclass(model_class)
-                or is_typeddict(model_class)
-            )
-            and preference != "pydantic"
-        )
+        or (_valid_model_class(model_class) and preference != "pydantic")
     )

tests/helpers.py

@@ -1,6 +1,6 @@
 import sys
 from dataclasses import dataclass
-from typing import Annotated
+from typing import Annotated, Generic, TypeVar
 
 from attrs import define
 from msgspec import Struct
@@ -12,6 +12,11 @@
 else:
     from typing_extensions import TypedDict
 
+try:
+    from typing import NotRequired
+except ImportError:
+    from typing_extensions import NotRequired
+
 
 @define
 class ADetails:
@@ -44,3 +49,14 @@ class PyDCDetails:
 class TDetails(TypedDict):
     name: str
     age: Annotated[int | None, Field(default=None)]
+
+
+N = TypeVar("N")
+
+
+class _TGDetails(TypedDict, Generic[N]):
+    name: N
+    age: NotRequired[int | None]
+
+
+TGDetails = _TGDetails[str]

tests/test_conversion.py

@@ -1,5 +1,5 @@
 from dataclasses import dataclass
-from typing import TypedDict
+from typing import Any, TypedDict
 
 import pytest
 from attrs import define
@@ -8,69 +8,70 @@
 from pydantic.dataclasses import dataclass as pydantic_dataclass
 
 from quart_schema.conversion import convert_headers, model_dump, model_load, model_schema
-from .helpers import ADetails, DCDetails, MDetails, PyDCDetails, PyDetails, TDetails
+from .helpers import ADetails, DCDetails, MDetails, PyDCDetails, PyDetails, TDetails, TGDetails
 
 
 class ValidationError(Exception):
     pass
 
 
-@pytest.mark.parametrize("type_", [ADetails, DCDetails, MDetails, PyDetails, PyDCDetails, TDetails])
+@pytest.mark.parametrize(
+    "type_",
+    [ADetails, DCDetails, MDetails, PyDetails, PyDCDetails, TDetails, TGDetails],
+)
 def test_model_dump(
-    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails],
+    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TGDetails],
 ) -> None:
     assert model_dump(type_(name="bob", age=2)) == {  # type: ignore
         "name": "bob",
         "age": 2,
     }
 
 
-@pytest.mark.parametrize(
-    "type_, preference",
-    [
-        (ADetails, "msgspec"),
-        (DCDetails, "msgspec"),
-        (DCDetails, "pydantic"),
-        (MDetails, "msgspec"),
-        (PyDetails, "pydantic"),
-        (PyDCDetails, "pydantic"),
-        (TDetails, "pydantic"),
-    ],
-)
-def test_model_dump_list(
-    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails],
-    preference: str,
-) -> None:
+test_types_and_preference = [
+    (ADetails, "msgspec"),
+    (DCDetails, "msgspec"),
+    (DCDetails, "pydantic"),
+    (MDetails, "msgspec"),
+    (TGDetails, "msgspec"),
+    (TGDetails, "pydantic"),
+    (PyDetails, "pydantic"),
+    (PyDCDetails, "pydantic"),
+    (TDetails, "pydantic"),
+]
+test_types = [
+    ADetails,
+    DCDetails,
+    MDetails,
+    PyDetails,
+    PyDCDetails,
+    TDetails,
+    TGDetails,
+]
+
+TestType = type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails]
+
+
+@pytest.mark.parametrize("type_, preference", test_types_and_preference)
+def test_model_dump_list(type_: TestType, preference: str) -> None:
     assert model_dump(
-        [type_(name="bob", age=2), type_(name="jim", age=3)], preference=preference
+        [type_(name="bob", age=2), type_(name="jim", age=3)],
+        preference=preference,
     ) == [{"name": "bob", "age": 2}, {"name": "jim", "age": 3}]
 
 
-@pytest.mark.parametrize("type_", [ADetails, DCDetails, MDetails, PyDetails, PyDCDetails, TDetails])
-def test_model_load(
-    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails],
-) -> None:
-    assert model_load({"name": "bob", "age": 2}, type_, exception_class=ValidationError) == type_(
-        name="bob", age=2
-    )
+@pytest.mark.parametrize("type_, preference", test_types_and_preference)
+def test_model_load(type_: TestType, preference: str) -> None:
+    assert model_load(
+        {"name": "bob", "age": 2},
+        type_,
+        exception_class=ValidationError,
+        preference=preference,
+    ) == type_(name="bob", age=2)
 
 
-@pytest.mark.parametrize(
-    "type_, preference",
-    [
-        (ADetails, "msgspec"),
-        (DCDetails, "msgspec"),
-        (DCDetails, "pydantic"),
-        (MDetails, "msgspec"),
-        (PyDetails, "pydantic"),
-        (PyDCDetails, "pydantic"),
-        (TDetails, "pydantic"),
-    ],
-)
-def test_model_load_list(
-    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails],
-    preference: str,
-) -> None:
+@pytest.mark.parametrize("type_, preference", test_types_and_preference)
+def test_model_load_list(type_: TestType, preference: str) -> None:
     assert model_load(
         [{"name": "bob", "age": 2}],
         list[type_],  # type: ignore
@@ -79,45 +80,57 @@ def test_model_load_list(
     ) == [type_(name="bob", age=2)]
 
 
-@pytest.mark.parametrize("type_", [ADetails, DCDetails, MDetails, PyDetails, PyDCDetails, TDetails])
-def test_model_load_error(
-    type_: type[ADetails | DCDetails | MDetails | PyDetails | PyDCDetails | TDetails],
-) -> None:
+@pytest.mark.parametrize("type_, preference", test_types_and_preference)
+def test_model_load_error(type_: TestType, preference: str) -> None:
     with pytest.raises(ValidationError):
-        model_load({"name": "bob", "age": "two"}, type_, exception_class=ValidationError)
+        model_load(
+            {"name": "bob", "age": "two"},
+            type_,
+            exception_class=ValidationError,
+            preference=preference,
+        )
 
 
-@pytest.mark.parametrize("type_", [ADetails, DCDetails, MDetails])
-def test_model_schema_msgspec(type_: type[ADetails | DCDetails | MDetails]) -> None:
-    assert model_schema(type_, preference="msgspec") == {
+@pytest.mark.parametrize("type_, preference", test_types_and_preference)
+def test_model_schema_msgspec(type_: TestType, preference: str) -> None:
+    schema = model_schema(
+        type_,
+        preference=preference,
+    )
+
+    # Base expected schema (common to both)
+    expected: dict[str, Any] = {
         "title": type_.__name__,
         "type": "object",
         "properties": {
             "name": {"type": "string"},
-            "age": {"anyOf": [{"type": "integer"}, {"type": "null"}], "default": None},
-        },
-        "required": ["name"],
-    }
-
-
-@pytest.mark.parametrize("type_", [DCDetails, PyDetails, PyDCDetails, TDetails])
-def test_model_schema_pydantic(
-    type_: type[DCDetails | PyDetails | PyDCDetails | TDetails],
-) -> None:
-    assert model_schema(type_, preference="pydantic") == {
-        "properties": {
-            "name": {"title": "Name", "type": "string"},
             "age": {
-                "anyOf": [{"type": "integer"}, {"type": "null"}],
+                "anyOf": [
+                    {"type": "integer"},
+                    {"type": "null"},
+                ],
                 "default": None,
-                "title": "Age",
             },
         },
         "required": ["name"],
-        "title": type_.__name__,
-        "type": "object",
     }
 
+    # Pydantic adds "title" fields to properties
+    if preference == "pydantic":
+        expected["properties"]["name"]["title"] = "Name"
+        expected["properties"]["age"]["title"] = "Age"
+
+    # For some reason the name for aliased type dicts
+    # includes the generic in msgspec
+    if preference == "msgspec" and type_ is TGDetails:
+        expected["title"] = "_TGDetails[str]"
+
+    # TGDetails does not include the default for age
+    if type_ is TGDetails:
+        del expected["properties"]["age"]["default"]
+
+    assert schema == expected
+
 
 @define
 class AHeaders: