Add support for native enum docstring

RELEASE.md

@@ -0,0 +1,24 @@
+Release type: patch
+
+Use native enum `__doc__` as the description for the schema enum type.
+
+```py
+# somewhere.py
+from enum import Enum
+
+
+class AnimalKind(Enum):
+    """The kind of animal."""
+
+    AXOLOTL, CAPYBARA = range(2)
+```
+
+This will generate the following schema:
+
+```graphql
+"""The kind of animal."""
+enum AnimalKind {
+  AXOLOTL
+  CAPYBARA
+}
+```

strawberry/annotation.py

@@ -187,7 +187,9 @@ def create_enum(self, evaled_type: Any) -> EnumDefinition:
         try:
             return evaled_type._enum_definition
         except AttributeError:
-            return strawberry_enum(evaled_type)._enum_definition
+            return strawberry_enum(
+                evaled_type, description=evaled_type.__doc__
+            )._enum_definition
 
     def create_list(self, evaled_type: Any) -> StrawberryList:
         item_type, *_ = get_args(evaled_type)

tests/enums/test_enum.py

@@ -200,3 +200,20 @@ def foo(self, foo: Foo) -> str:
     assert not res.errors
     assert res.data
     assert res.data["foo"] == "baz"
+
+
+def test_default_enum_with_docstring() -> None:
+    class Foo(Enum):
+        """This is a Foo enum."""
+
+        BAR = "bar"
+        BAZ = "baz"
+
+    @strawberry.type
+    class Query:
+        @strawberry.field
+        def foo(self, foo: Foo) -> str:
+            return foo.value
+
+    definition = get_object_definition(Query, strict=True)
+    assert definition.fields[0].arguments[0].type.description == Foo.__doc__