fix(graphql): make graphql locations optional [backport 3.2]

ddtrace/contrib/internal/graphql/patch.py

@@ -332,12 +332,13 @@ def _set_span_errors(errors: List[GraphQLError], span: Span) -> None:
     error_msgs = "\n".join([str(error) for error in errors])
     span.set_tag_str(ERROR_MSG, error_msgs)
     for error in errors:
-        locations = [f"{loc.formatted['line']}:{loc.formatted['column']}" for loc in error.locations]
         attributes = {
             "message": error.message,
             "type": span.get_tag("error.type"),
-            "locations": locations,
         }
+        if error.locations:
+            locations = [f"{loc.formatted['line']}:{loc.formatted['column']}" for loc in error.locations]
+            attributes["locations"] = locations
 
         if error.__traceback__:
             exc_type, exc_val, exc_tb = type(error), error, error.__traceback__

releasenotes/notes/fix-graphql-locations-attribute-27a66fbb003eb510.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    GraphQL: Fixes an issue in GraphQL patching that threw an error when locations (an `Optional` field) is `None`. This checks for locations before setting attributes.

tests/contrib/graphql/test_graphql.py

@@ -195,6 +195,18 @@ def test_graphql_execute_sync_with_middlware_manager(
         assert res2.data == {"hello": "friend"}
 
 
+@snapshot(ignores=["meta.error.stack", "meta.events"])
+def test_regression_graphql_error_locations_none():
+    """
+    Ensure GraphQLError with `locations=None` does not cause patching issues.
+    """
+    error = graphql.GraphQLError(message="Test error with no locations")
+    error.locations = None
+    result = graphql.ExecutionResult(data=None, errors=[error])
+
+    assert result.errors[0].locations is None
+
+
 @pytest.mark.snapshot
 @pytest.mark.skipif(graphql_version < (3, 0), reason="graphql.graphql_sync is NOT supported in v2.0")
 @pytest.mark.parametrize(