Add check for serializers.HiddenField on fields_for_serializer function (graphql-python#1419)

* Add check for `serializers.HiddenField` on fields_for_serializer function

* Add pre-commit changes

Author: sezginacer

graphene_django/rest_framework/mutation.py

@@ -39,6 +39,9 @@ def fields_for_serializer(
                 field.read_only
                 and is_input
                 and lookup_field != name,  # don't show read_only fields in Input
+                isinstance(
+                    field, serializers.HiddenField
+                ),  # don't show hidden fields in Input
             ]
         )
 

graphene_django/rest_framework/tests/test_mutation.py

@@ -164,6 +164,21 @@ class Meta:
     ), "'cool_name' is read_only field and shouldn't be on arguments"
 
 
+def test_hidden_fields():
+    class SerializerWithHiddenField(serializers.Serializer):
+        cool_name = serializers.CharField()
+        user = serializers.HiddenField(default=serializers.CurrentUserDefault())
+
+    class MyMutation(SerializerMutation):
+        class Meta:
+            serializer_class = SerializerWithHiddenField
+
+    assert "cool_name" in MyMutation.Input._meta.fields
+    assert (
+        "user" not in MyMutation.Input._meta.fields
+    ), "'user' is hidden field and shouldn't be on arguments"
+
+
 def test_nested_model():
     class MyFakeModelGrapheneType(DjangoObjectType):
         class Meta: