added optional list tests

src/drf_pydantic/parse.py

@@ -6,9 +6,9 @@
 
 import pydantic
 import pydantic.fields
+import pydantic_core
 
-from pydantic_core import PydanticUndefined, Url
-from rest_framework import serializers
+from rest_framework import serializers  # type: ignore
 
 from drf_pydantic.errors import FieldConversionError, ModelConversionError
 from drf_pydantic.utils import get_union_members, is_scalar
@@ -27,14 +27,14 @@
     # String fields
     str: serializers.CharField,
     pydantic.EmailStr: serializers.EmailField,
-    # Regex implemented as a special case
-    # WARN This is what pydantic converts pydantic.HttpUrl to
-    Url: serializers.URLField,
+    # * Regex implemented as a special case
+    # WARN pydantic converts pydantic.HttpUrl to pydantic_core.Url
+    pydantic_core.Url: serializers.URLField,
     uuid.UUID: serializers.UUIDField,
     # Numeric fields
     int: serializers.IntegerField,
     float: serializers.FloatField,
-    # Decimal implemented as a special case
+    # * Decimal implemented as a special case
     # Date and time fields
     datetime.datetime: serializers.DateTimeField,
     datetime.date: serializers.DateField,
@@ -116,7 +116,7 @@ def _convert_field(
         "required": field.is_required(),
     }
     _default_value = field.get_default(call_default_factory=True)
-    if _default_value is not PydanticUndefined:
+    if _default_value is not pydantic_core.PydanticUndefined:
         drf_field_kwargs["default"] = _default_value
 
     # Process constraints

tests/test_fields.py

@@ -192,6 +192,28 @@ class Person(BaseModel):
 
         assert isinstance(serializer.fields["friends"], serializers.ListField)
         assert isinstance(serializer.fields["friends"].child, serializers.CharField)
+        assert serializer.fields["friends"].allow_null is False
+
+    def test_optional_list_with_optional(self):
+        class Person(BaseModel):
+            friends: typing.Optional[list[str]]
+
+        serializer = Person.drf_serializer()
+
+        assert isinstance(serializer.fields["friends"], serializers.ListField)
+        assert isinstance(serializer.fields["friends"].child, serializers.CharField)
+        assert serializer.fields["friends"].allow_null is True
+
+    @pytest.mark.skipif(sys.version_info < (3, 10), reason="Requires Python 3.10+")
+    def test_optional_list_with_pipe(self):
+        class Person(BaseModel):
+            friends: list[str] | None  # type: ignore
+
+        serializer = Person.drf_serializer()
+
+        assert isinstance(serializer.fields["friends"], serializers.ListField)
+        assert isinstance(serializer.fields["friends"].child, serializers.CharField)
+        assert serializer.fields["friends"].allow_null is True
 
     def test_tuple_with_ellipsis(self):
         class Person(BaseModel):
@@ -288,7 +310,7 @@ class Person(BaseModel):
     @pytest.mark.skipif(sys.version_info < (3, 10), reason="Requires Python 3.10+")
     def test_optional_type_with_pipe(self):
         class Person(BaseModel):
-            name: str | None
+            name: str | None  # type: ignore
 
         serializer = Person.drf_serializer()