Disable Reply in thread on moved system messages

src/libs/ReportUtils.ts

@@ -216,6 +216,7 @@ import {
     isIntegrationMessageAction,
     isMoneyRequestAction,
     isMovedAction,
+    isMovedTransactionAction,
     isOlderReportAction,
     isPendingRemove,
     isReopenedAction,
@@ -11686,6 +11687,7 @@ function getNonHeldAndFullAmount(
  * - The action is a split expense action
  * - The action is deleted and is not threaded
  * - The report is archived and the action is not threaded
+ * - The action is a moved system message and is not threaded (moved actions can't be threaded server-side, so offering "Reply in thread" leads to a failed thread-creation call)
  * - The action is a whisper action and it's neither a report preview nor IOU action
  * - The action is the thread's first chat
  */
@@ -11696,12 +11698,14 @@ function shouldDisableThread(reportAction: OnyxInputOrEntry<ReportAction>, isThr
     const isIOUAction = isMoneyRequestAction(reportAction);
     const isWhisperActionLocal = isWhisperAction(reportAction) || isActionableTrackExpense(reportAction);
     const isDynamicWorkflowRoutedAction = isActionOfType(reportAction, CONST.REPORT.ACTIONS.TYPE.DYNAMIC_EXTERNAL_WORKFLOW_ROUTED);
+    const isMovedSystemMessage = isMovedAction(reportAction) || isMovedTransactionAction(reportAction);
     const isActionDisabled = CONST.REPORT.ACTIONS.THREAD_DISABLED.some((action: string) => action === reportAction?.actionName);
     return (
         isActionDisabled ||
         isSplitBillAction ||
         (isDeletedActionLocal && !reportAction?.childVisibleActionCount) ||
         (isReportArchived && !reportAction?.childVisibleActionCount) ||
+        (isMovedSystemMessage && !reportAction?.childVisibleActionCount) ||
         (isWhisperActionLocal && !isReportPreviewActionLocal && !isIOUAction) ||
         isThreadReportParentAction ||
         isDynamicWorkflowRoutedAction

tests/unit/ReportUtilsTest.ts

@@ -5325,6 +5325,36 @@ describe('ReportUtils', () => {
                 expect(isThreadDisabled).toBeTruthy();
             });
         });
+
+        describe('moved system messages', () => {
+            it.each([CONST.REPORT.ACTIONS.TYPE.MOVED, CONST.REPORT.ACTIONS.TYPE.MOVED_TRANSACTION])('should be disabled for a %s action with no child visible action count', (actionName) => {
+                // Given a moved system message that has never been threaded
+                const reportAction = createMock<ReportAction>({
+                    actionName,
+                    childVisibleActionCount: 0,
+                });
+
+                // When it's checked to see if the thread should be disabled
+                const isThreadDisabled = shouldDisableThread(reportAction, false);
+
+                // Then the thread should be disabled so the doomed thread-creation call is never made
+                expect(isThreadDisabled).toBeTruthy();
+            });
+
+            it.each([CONST.REPORT.ACTIONS.TYPE.MOVED, CONST.REPORT.ACTIONS.TYPE.MOVED_TRANSACTION])('should be enabled for a %s action that has already been threaded', (actionName) => {
+                // Given a moved system message that already has a legitimately threaded child
+                const reportAction = createMock<ReportAction>({
+                    actionName,
+                    childVisibleActionCount: 1,
+                });
+
+                // When it's checked to see if the thread should be disabled
+                const isThreadDisabled = shouldDisableThread(reportAction, false);
+
+                // Then the thread should stay enabled so the existing thread remains reachable
+                expect(isThreadDisabled).toBeFalsy();
+            });
+        });
     });
 
     describe('isChatUsedForOnboarding', () => {