Fix info by adding a custom __class_getitem__

RELEASE.md

@@ -0,0 +1,22 @@
+Release type: patch
+
+This release properly allows passing one argument to the `Info` class.
+
+This is now fully supported:
+
+```python
+import strawberry
+
+from typing import TypedDict
+
+
+class Context(TypedDict):
+    user_id: str
+
+
+@strawberry.type
+class Query:
+    @strawberry.field
+    def info(self, info: strawberry.Info[Context]) -> str:
+        return info.context["user_id"]
+```

strawberry/types/info.py

@@ -10,6 +10,7 @@
     Generic,
     List,
     Optional,
+    Tuple,
     Type,
     Union,
 )
@@ -38,6 +39,21 @@ class Info(Generic[ContextType, RootValueType]):
     _raw_info: GraphQLResolveInfo
     _field: StrawberryField
 
+    def __class_getitem__(cls, types: Union[type, Tuple[type, ...]]) -> Type[Info]:
+        """Workaround for when passing only one type.
+
+        Python doesn't yet support directly passing only one type to a generic class
+        that has typevars with defaults. This is a workaround for that.
+
+        See:
+        https://discuss.python.org/t/passing-only-one-typevar-of-two-when-using-defaults/49134
+        """
+
+        if not isinstance(types, tuple):
+            types = (types, Any)  # type: ignore
+
+        return super().__class_getitem__(types)  # type: ignore
+
     @property
     def field_name(self) -> str:
         return self._raw_info.field_name

tests/test_info.py

@@ -0,0 +1,25 @@
+from typing import Any
+
+import pytest
+
+import strawberry
+
+
+def test_can_use_info_with_two_arguments():
+    CustomInfo = strawberry.Info[int, str]
+
+    assert CustomInfo.__args__ == (int, str)
+
+
+def test_can_use_info_with_one_argument():
+    CustomInfo = strawberry.Info[int]
+
+    assert CustomInfo.__args__ == (int, Any)
+
+
+def test_cannot_use_info_with_more_than_two_arguments():
+    with pytest.raises(
+        TypeError,
+        match="Too many (arguments|parameters) for <class '.*.Info'>; actual 3, expected 2",
+    ):
+        strawberry.Info[int, str, int]  # type: ignore