Allow mutations to return mappings

Author: Cito

src/graphql_relay/mutation/mutation.py

@@ -1,3 +1,4 @@
+from collections.abc import Mapping
 from inspect import iscoroutinefunction
 from typing import Any, Callable, Dict, Optional
 
@@ -82,7 +83,10 @@ async def resolve(_root: Any, info: GraphQLResolveInfo, input: Dict) -> Any:
             clientMutationId = input.get("clientMutationId")
             if payload is None:
                 return NullResult(clientMutationId)
-            payload.clientMutationId = clientMutationId
+            if isinstance(payload, Mapping):
+                payload["clientMutationId"] = clientMutationId  # type: ignore
+            else:
+                payload.clientMutationId = clientMutationId
             return payload
 
     else:
@@ -95,7 +99,10 @@ def resolve(  # type: ignore
             clientMutationId = input.get("clientMutationId")
             if payload is None:
                 return NullResult(clientMutationId)
-            payload.clientMutationId = clientMutationId  # type: ignore
+            if isinstance(payload, Mapping):
+                payload["clientMutationId"] = clientMutationId  # type: ignore
+            else:
+                payload.clientMutationId = clientMutationId  # type: ignore
             return payload
 
     return GraphQLField(

tests/mutation/test_mutation.py

@@ -154,7 +154,7 @@ def can_access_root_value():
         )
 
     def supports_mutations_returning_null():
-        def null_resolve(_info, **_input) -> None:
+        def null_resolve(_info, **_input):
             return None
 
         some_mutation = mutation_with_client_mutation_id(
@@ -176,7 +176,7 @@ def null_resolve(_info, **_input) -> None:
 
     @mark.asyncio
     async def supports_async_mutations_returning_null():
-        async def null_resolve(_info, **_input) -> None:
+        async def null_resolve(_info, **_input):
             return None
 
         some_mutation = mutation_with_client_mutation_id(
@@ -234,6 +234,61 @@ def resolve(cls, obj, _info):
             None,
         )
 
+    def supports_mutations_returning_mappings():
+        def dict_mutate(_info, **_input):
+            return {"some_data": 1}
+
+        def dict_resolve(obj, _info):
+            return obj["some_data"]
+
+        some_mutation = mutation_with_client_mutation_id(
+            "SomeMutation",
+            {},
+            {"result": GraphQLField(GraphQLInt, resolve=dict_resolve)},
+            dict_mutate,
+        )
+        schema = wrap_in_schema({"someMutation": some_mutation})
+        source = """
+            mutation {
+              someMutation(input: {clientMutationId: "abc"}) {
+                result
+                clientMutationId
+              }
+            }
+            """
+        assert graphql_sync(schema, source) == (
+            {"someMutation": {"result": 1, "clientMutationId": "abc"}},
+            None,
+        )
+
+    @mark.asyncio
+    async def supports_async_mutations_returning_mappings():
+        async def dict_mutate(_info, **_input):
+            return {"some_data": 1}
+
+        async def dict_resolve(obj, _info):
+            return obj["some_data"]
+
+        some_mutation = mutation_with_client_mutation_id(
+            "SomeMutation",
+            {},
+            {"result": GraphQLField(GraphQLInt, resolve=dict_resolve)},
+            dict_mutate,
+        )
+        schema = wrap_in_schema({"someMutation": some_mutation})
+        source = """
+            mutation {
+              someMutation(input: {clientMutationId: "abc"}) {
+                result
+                clientMutationId
+              }
+            }
+            """
+        assert await graphql(schema, source) == (
+            {"someMutation": {"result": 1, "clientMutationId": "abc"}},
+            None,
+        )
+
     def generates_correct_types():
         some_mutation = mutation_with_client_mutation_id(
             "SomeMutation",