fix: Input fields and Arguments can now be deprecated (#1472)

Non-required InputFields and arguments now support deprecation via setting the `deprecation_reason` argument upon creation.

graphene/types/argument.py

@@ -31,18 +31,22 @@ class Argument(MountedType):
         type (class for a graphene.UnmountedType): must be a class (not an instance) of an
             unmounted graphene type (ex. scalar or object) which is used for the type of this
             argument in the GraphQL schema.
-        required (bool): indicates this argument as not null in the graphql schema. Same behavior
+        required (optional, bool): indicates this argument as not null in the graphql schema. Same behavior
             as graphene.NonNull. Default False.
-        name (str): the name of the GraphQL argument. Defaults to parameter name.
-        description (str): the description of the GraphQL argument in the schema.
-        default_value (Any): The value to be provided if the user does not set this argument in
+        name (optional, str): the name of the GraphQL argument. Defaults to parameter name.
+        description (optional, str): the description of the GraphQL argument in the schema.
+        default_value (optional, Any): The value to be provided if the user does not set this argument in
             the operation.
+        deprecation_reason (optional, str): Setting this value indicates that the argument is
+            depreciated and may provide instruction or reason on how for clients to proceed. Cannot be
+            set if the argument is required (see spec).
     """
 
     def __init__(
         self,
         type_,
         default_value=Undefined,
+        deprecation_reason=None,
         description=None,
         name=None,
         required=False,
@@ -51,12 +55,16 @@ def __init__(
         super(Argument, self).__init__(_creation_counter=_creation_counter)
 
         if required:
+            assert (
+                deprecation_reason is None
+            ), f"Argument {name} is required, cannot deprecate it."
             type_ = NonNull(type_)
 
         self.name = name
         self._type = type_
         self.default_value = default_value
         self.description = description
+        self.deprecation_reason = deprecation_reason
 
     @property
     def type(self):
@@ -68,6 +76,7 @@ def __eq__(self, other):
             and self.type == other.type
             and self.default_value == other.default_value
             and self.description == other.description
+            and self.deprecation_reason == other.deprecation_reason
         )
 
 

graphene/types/inputfield.py

@@ -55,11 +55,14 @@ def __init__(
         description=None,
         required=False,
         _creation_counter=None,
-        **extra_args
+        **extra_args,
     ):
         super(InputField, self).__init__(_creation_counter=_creation_counter)
         self.name = name
         if required:
+            assert (
+                deprecation_reason is None
+            ), f"InputField {name} is required, cannot deprecate it."
             type_ = NonNull(type_)
         self._type = type_
         self.deprecation_reason = deprecation_reason

graphene/types/schema.py

@@ -316,6 +316,7 @@ def create_fields_for_type(self, graphene_type, is_input_type=False):
                     default_value=field.default_value,
                     out_name=name,
                     description=field.description,
+                    deprecation_reason=field.deprecation_reason,
                 )
             else:
                 args = {}
@@ -327,6 +328,7 @@ def create_fields_for_type(self, graphene_type, is_input_type=False):
                         out_name=arg_name,
                         description=arg.description,
                         default_value=arg.default_value,
+                        deprecation_reason=arg.deprecation_reason,
                     )
                 subscribe = field.wrap_subscribe(
                     self.get_function_for_type(

graphene/types/tests/test_argument.py

@@ -18,8 +18,20 @@ def test_argument():
 
 
 def test_argument_comparasion():
-    arg1 = Argument(String, name="Hey", description="Desc", default_value="default")
-    arg2 = Argument(String, name="Hey", description="Desc", default_value="default")
+    arg1 = Argument(
+        String,
+        name="Hey",
+        description="Desc",
+        default_value="default",
+        deprecation_reason="deprecated",
+    )
+    arg2 = Argument(
+        String,
+        name="Hey",
+        description="Desc",
+        default_value="default",
+        deprecation_reason="deprecated",
+    )
 
     assert arg1 == arg2
     assert arg1 != String()
@@ -40,6 +52,30 @@ def test_to_arguments():
     }
 
 
+def test_to_arguments_deprecated():
+    args = {"unmounted_arg": String(required=False, deprecation_reason="deprecated")}
+
+    my_args = to_arguments(args)
+    assert my_args == {
+        "unmounted_arg": Argument(
+            String, required=False, deprecation_reason="deprecated"
+        ),
+    }
+
+
+def test_to_arguments_required_deprecated():
+    args = {
+        "unmounted_arg": String(
+            required=True, name="arg", deprecation_reason="deprecated"
+        )
+    }
+
+    with raises(AssertionError) as exc_info:
+        to_arguments(args)
+
+    assert str(exc_info.value) == "Argument arg is required, cannot deprecate it."
+
+
 def test_to_arguments_raises_if_field():
     args = {"arg_string": Field(String)}
 

graphene/types/tests/test_field.py

@@ -128,13 +128,20 @@ def test_field_name_as_argument():
 
 def test_field_source_argument_as_kw():
     MyType = object()
-    field = Field(MyType, b=NonNull(True), c=Argument(None), a=NonNull(False))
+    deprecation_reason = "deprecated"
+    field = Field(
+        MyType,
+        b=NonNull(True),
+        c=Argument(None, deprecation_reason=deprecation_reason),
+        a=NonNull(False),
+    )
     assert list(field.args) == ["b", "c", "a"]
     assert isinstance(field.args["b"], Argument)
     assert isinstance(field.args["b"].type, NonNull)
     assert field.args["b"].type.of_type is True
     assert isinstance(field.args["c"], Argument)
     assert field.args["c"].type is None
+    assert field.args["c"].deprecation_reason == deprecation_reason
     assert isinstance(field.args["a"], Argument)
     assert isinstance(field.args["a"].type, NonNull)
     assert field.args["a"].type.of_type is False

graphene/types/tests/test_inputfield.py

@@ -1,5 +1,7 @@
 from functools import partial
 
+from pytest import raises
+
 from ..inputfield import InputField
 from ..structures import NonNull
 from .utils import MyLazyType
@@ -12,6 +14,22 @@ def test_inputfield_required():
     assert field.type.of_type == MyType
 
 
+def test_inputfield_deprecated():
+    MyType = object()
+    deprecation_reason = "deprecated"
+    field = InputField(MyType, required=False, deprecation_reason=deprecation_reason)
+    assert isinstance(field.type, type(MyType))
+    assert field.deprecation_reason == deprecation_reason
+
+
+def test_inputfield_required_deprecated():
+    MyType = object()
+    with raises(AssertionError) as exc_info:
+        InputField(MyType, name="input", required=True, deprecation_reason="deprecated")
+
+    assert str(exc_info.value) == "InputField input is required, cannot deprecate it."
+
+
 def test_inputfield_with_lazy_type():
     MyType = object()
     field = InputField(lambda: MyType)