Handle missing childManagerAccountID: fall back to IOU badge when oldestTaskAction is undefined

When childManagerAccountID is not populated (backend bug before opening report),
oldestTaskAction is undefined. Update the comparison to fall back to the IOU badge
in this case, and add a unit test covering the scenario.

Co-authored-by: Aimane Chnaif <aimane-chnaif@users.noreply.github.com>

Author: MelvinBot

src/libs/ReportUtils.ts

@@ -4279,7 +4279,7 @@ function getReasonAndReportActionThatRequiresAttention(
             .at(0);
 
         // If there's a valid IOU action that is older than the task, use the IOU badge instead
-        if (hasValidIOUAction && iouReportActionToApproveOrPay?.created && oldestTaskAction?.created && iouReportActionToApproveOrPay.created < oldestTaskAction.created) {
+        if (hasValidIOUAction && iouReportActionToApproveOrPay?.created && (!oldestTaskAction || iouReportActionToApproveOrPay.created < oldestTaskAction.created)) {
             return {
                 reason: CONST.REQUIRES_ATTENTION_REASONS.HAS_CHILD_REPORT_AWAITING_ACTION,
                 reportAction: iouReportActionToApproveOrPay,

tests/unit/ReportUtilsTest.ts

@@ -9399,6 +9399,55 @@ describe('ReportUtils', () => {
             expect(result?.actionBadge).toBe(CONST.REPORT.ACTION_BADGE.TASK);
         });
 
+        it('should return the IOU badge when task action has no childManagerAccountID (backend bug before opening report)', async () => {
+            const iouReportID = 'iou-report-for-missing-manager';
+
+            // Task action without childManagerAccountID — simulates the backend bug
+            // where childManagerAccountID is missing before the report is opened
+            const taskAction: ReportAction = {
+                reportActionID: 'task-action-no-manager',
+                actionName: CONST.REPORT.ACTIONS.TYPE.CARD_MISSING_ADDRESS,
+                childType: CONST.REPORT.TYPE.TASK,
+                childReportID: 'task-report-no-manager',
+                created: '2024-01-01 00:00:00',
+                originalMessage: {
+                    assigneeAccountID: currentUserAccountID,
+                    cardID: 99003,
+                },
+            };
+
+            const iouAction: ReportAction = {
+                reportActionID: 'iou-action-fallback',
+                actionName: CONST.REPORT.ACTIONS.TYPE.REPORT_PREVIEW,
+                childType: CONST.REPORT.TYPE.IOU,
+                childReportID: iouReportID,
+                childManagerAccountID: currentUserAccountID,
+                created: '2024-01-02 00:00:00',
+                message: [{html: 'iou preview', text: 'iou preview', type: 'COMMENT'}],
+            };
+
+            const workspaceChat = {
+                ...createPolicyExpenseChat(42003),
+                hasOutstandingChildTask: true,
+                hasOutstandingChildRequest: true,
+                iouReportID,
+            };
+
+            await Onyx.set(`${ONYXKEYS.COLLECTION.REPORT}${workspaceChat.reportID}`, workspaceChat);
+            await Onyx.set(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${workspaceChat.reportID}`, {
+                [taskAction.reportActionID]: taskAction,
+                [iouAction.reportActionID]: iouAction,
+            });
+            await waitForBatchedUpdates();
+
+            const {result: isReportArchived} = renderHook(() => useReportIsArchived(workspaceChat.reportID));
+            const result = getReasonAndReportActionThatRequiresAttention(workspaceChat, currentUserEmail, currentUserAccountID, undefined, isReportArchived.current);
+
+            // When oldestTaskAction is undefined (no childManagerAccountID), IOU badge should be returned
+            expect(result?.reason).toBe(CONST.REQUIRES_ATTENTION_REASONS.HAS_CHILD_REPORT_AWAITING_ACTION);
+            expect(result?.reportAction?.reportActionID).toBe('iou-action-fallback');
+        });
+
         it('should return the earliest matching report action for invoice rooms with missing bank account', async () => {
             const invoiceRoomID = '50000';
             const olderChildReportID = '50001';