fix: bulk edit, does not clobber taxAmount when the transaction taxCode is unknown to the policy

Author: LukasMod

src/libs/actions/IOU/BulkEdit.ts

@@ -170,12 +170,16 @@ function updateMultipleMoneyRequests({
         }
         // When bulk-editing amount on a taxed expense without also changing taxCode, recompute
         // taxAmount from the transaction's existing taxCode so offline optimistic data and the
-        // queued payload stay in sync with the new amount
+        // queued payload stay in sync with the new amount. Skip when the rate can't be resolved
+        // (e.g. cross-policy bulk edit where the transaction's own policy is missing from cache)
+        // to avoid silently overwriting a non-zero taxAmount with 0.
         if (changes.amount !== undefined && !changes.taxCode && transaction.taxCode && supportsExpenseFields && canEditField(CONST.EDIT_REQUEST_FIELD.TAX_RATE)) {
             const taxValue = getTaxValue(transactionPolicy, transaction, transaction.taxCode);
-            const decimals = getCurrencyDecimals(getCurrency(transaction));
-            const taxAmount = calculateTaxAmount(taxValue, Math.abs(changes.amount), decimals);
-            transactionChanges.taxAmount = convertToBackendAmount(taxAmount);
+            if (taxValue) {
+                const decimals = getCurrencyDecimals(getCurrency(transaction));
+                const taxAmount = calculateTaxAmount(taxValue, Math.abs(changes.amount), decimals);
+                transactionChanges.taxAmount = convertToBackendAmount(taxAmount);
+            }
         }
         if (changes.currency && canEditField(CONST.EDIT_REQUEST_FIELD.CURRENCY)) {
             transactionChanges.currency = changes.currency;

tests/actions/IOUTest/BulkEditTest.ts

@@ -1369,6 +1369,70 @@ describe('actions/IOU/BulkEdit', () => {
             writeSpy.mockRestore();
             canEditFieldSpy.mockRestore();
         });
+
+        it('does not clobber taxAmount when the transaction taxCode is unknown to the policy', () => {
+            // Cross-policy bulk edit / stale cache: the transaction has a taxCode that doesn't
+            // exist in the resolved policy's taxRates. getTaxValue returns undefined and
+            // calculateTaxAmount short-circuits to 0 — we must not write that 0 over a non-zero
+            // existing taxAmount.
+            const transactionID = 'transaction-unresolvable-tax';
+            const iouReportID = 'iou-unresolvable-tax';
+            const policy: Policy = {
+                ...createRandomPolicy(1, CONST.POLICY.TYPE.TEAM),
+                taxRates: CONST.DEFAULT_TAX,
+            };
+
+            const iouReport: Report = {
+                ...createRandomReport(2, undefined),
+                reportID: iouReportID,
+                policyID: policy.id,
+                type: CONST.REPORT.TYPE.EXPENSE,
+            };
+
+            const reports = {
+                [`${ONYXKEYS.COLLECTION.REPORT}${iouReportID}`]: iouReport,
+            };
+
+            const transaction: Transaction = {
+                ...createRandomTransaction(1),
+                transactionID,
+                reportID: iouReportID,
+                amount: -1000,
+                currency: CONST.CURRENCY.USD,
+                taxCode: 'id_TAX_RATE_NOT_IN_POLICY',
+                taxAmount: -48,
+            };
+            const transactions = {
+                [`${ONYXKEYS.COLLECTION.TRANSACTION}${transactionID}`]: transaction,
+            };
+
+            const canEditFieldSpy = jest.spyOn(require('@libs/ReportUtils'), 'canEditFieldOfMoneyRequest').mockReturnValue(true);
+            // eslint-disable-next-line rulesdir/no-multiple-api-calls
+            const writeSpy = jest.spyOn(API, 'write').mockImplementation(jest.fn());
+
+            updateMultipleMoneyRequests({
+                transactionIDs: [transactionID],
+                changes: {amount: -2000},
+                policy,
+                reports,
+                transactions,
+                reportActions: {},
+                policyCategories: undefined,
+                policyTags: {},
+                hash: undefined,
+                introSelected: undefined,
+                betas: undefined,
+            });
+
+            const params = writeSpy.mock.calls.at(0)?.[1] as {updates: string};
+            const updates = JSON.parse(params.updates) as {amount: number; taxAmount?: number};
+            expect(updates.amount).toBe(-2000);
+            // No taxAmount should be queued — we couldn't resolve a rate to recompute from.
+            expect(updates.taxAmount).toBeUndefined();
+
+            writeSpy.mockRestore();
+            canEditFieldSpy.mockRestore();
+        });
     });
 
     describe('bulk edit draft transaction', () => {