Dec 16, 2024 · Dec 14, 2024
diff --git a/pydantic/_internal/_typing_extra.py b/pydantic/_internal/_typing_extra.py
    return _is_typing_name(get_origin(tp), name='Literal')


 # TODO remove and replace with `get_args` when we drop support for Python 3.8
 # (see https://docs.python.org/3/whatsnew/3.9.html#id4).
 def literal_values(tp: Any, /) -> list[Any]:
    """Return the values contained in the provided `Literal` special form."""
    """Return the values contained in the provided `Literal` special form.

    If one of the literal values is a PEP 695 type alias, recursively parse
    the type alias' `__value__` to unpack literal values as well. This function
    *doesn't* check that the type alias is referencing a `Literal` special form,
    so unexpected values could be unpacked.
    """
    # TODO When we drop support for Python 3.8, there's no need to check of `is_literal`
    # here, as Python unpacks nested `Literal` forms in 3.9+.
    # (see https://docs.python.org/3/whatsnew/3.9.html#id4).
    if not is_literal(tp):
        # Note: we could also check for generic aliases with a type alias as an origin.
        # However, it is very unlikely that this happens as type variables can't appear in
        # `Literal` forms, so the only valid (but unnecessary) use case would be something like:
        # `type Test[T] = Literal['whatever']` (and then use `Test[SomeType]`).
        if is_type_alias_type(tp):
            # Note: accessing `__value__` could raise a `NameError`, but we just let
            # the exception be raised as there's not much we can do if this happens.
            return literal_values(tp.__value__)

        return [tp]

    values = get_args(tp)
diff --git a/tests/test_json_schema.py b/tests/test_json_schema.py
 from packaging.version import Version
 from pydantic_core import CoreSchema, SchemaValidator, core_schema, to_jsonable_python
 from pydantic_core.core_schema import ValidatorFunctionWrapHandler
 from typing_extensions import Annotated, Literal, Self, TypedDict, deprecated
 from typing_extensions import Annotated, Literal, Self,TypeAliasType,TypedDict, deprecated

 import pydantic
 from pydantic import (
    }


 def test_literal_schema_type_aliases() -> None:
    TestType0 = TypeAliasType('TestType0', Literal['a'])
    TestType1 = TypeAliasType('TestType1', Literal[TestType0, 'b'])
    TestType2 = TypeAliasType('TestType2', Literal[TestType1, 'c'])

    assert TypeAdapter(TestType2).json_schema() == {
        'enum': ['a', 'b', 'c'],
        'type': 'string',
    }


 def test_literal_enum():
    class MyEnum(str, Enum):
        FOO = 'foo'
Original file line number	Diff line number	Diff line change
Expand Up		@@ -85,11 +85,27 @@ def is_literal(tp: Any, /) -> bool:
		return _is_typing_name(get_origin(tp), name='Literal')


		# TODO remove and replace with `get_args` when we drop support for Python 3.8
		# (see https://docs.python.org/3/whatsnew/3.9.html#id4).
		def literal_values(tp: Any, /) -> list[Any]:
		"""Return the values contained in the provided `Literal` special form."""
		"""Return the values contained in the provided `Literal` special form.

		If one of the literal values is a PEP 695 type alias, recursively parse
		the type alias' `__value__` to unpack literal values as well. This function
		doesn't check that the type alias is referencing a `Literal` special form,
		so unexpected values could be unpacked.
		"""
		# TODO When we drop support for Python 3.8, there's no need to check of `is_literal`
		# here, as Python unpacks nested `Literal` forms in 3.9+.
		# (see https://docs.python.org/3/whatsnew/3.9.html#id4).
		if not is_literal(tp):
		# Note: we could also check for generic aliases with a type alias as an origin.
		# However, it is very unlikely that this happens as type variables can't appear in
		# `Literal` forms, so the only valid (but unnecessary) use case would be something like:
		# `type Test[T] = Literal['whatever']` (and then use `Test[SomeType]`).
		if is_type_alias_type(tp):
		# Note: accessing `__value__` could raise a `NameError`, but we just let
		# the exception be raised as there's not much we can do if this happens.
		return literal_values(tp.__value__)

		return [tp]

		values = get_args(tp)
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -37,7 +37,7 @@
		from packaging.version import Version
		from pydantic_core import CoreSchema, SchemaValidator, core_schema, to_jsonable_python
		from pydantic_core.core_schema import ValidatorFunctionWrapHandler
		from typing_extensions import Annotated, Literal, Self, TypedDict, deprecated
		from typing_extensions import Annotated, Literal, Self,TypeAliasType,TypedDict, deprecated

		import pydantic
		from pydantic import (
Expand DownExpand Up		@@ -2378,6 +2378,17 @@ class Model(BaseModel):
		}


		def test_literal_schema_type_aliases() -> None:
		TestType0 = TypeAliasType('TestType0', Literal['a'])
		TestType1 = TypeAliasType('TestType1', Literal[TestType0, 'b'])
		TestType2 = TypeAliasType('TestType2', Literal[TestType1, 'c'])

		assert TypeAdapter(TestType2).json_schema() == {
		'enum': ['a', 'b', 'c'],
		'type': 'string',
		}


		def test_literal_enum():
		class MyEnum(str, Enum):
		FOO = 'foo'
Expand Down