Patch Your spend "Awaiting approval" total when splitting a submitted expense offline

Splitting a SUBMITTED expense changed the report's reimbursable total but never
patched the cached "Awaiting approval" snapshot, so the Home total stayed stale
offline. Add getYourSpendSnapshotSplitUpdates and wire it into updateSplitTransactions
using the existing report-total delta.

Author: adamgrzybowski

src/libs/actions/IOU/SplitTransactionUpdate.ts

@@ -66,6 +66,7 @@ import {addPendingNewTransactionIDs} from './PendingNewTransactions';
 import {getDeleteTrackExpenseInformation} from './TrackExpense';
 import {getUpdateMoneyRequestParams} from './UpdateMoneyRequest';
 import type {UpdateMoneyRequestDataKeys} from './UpdateMoneyRequest';
+import {getYourSpendSnapshotSplitUpdates} from './YourSpendSnapshotUpdate';
 
 type UpdateSplitTransactionsParams = {
     allTransactionsList: OnyxCollection<OnyxTypes.Transaction>;
@@ -1787,6 +1788,20 @@ function updateSplitTransactions({
         }
     }
 
+    // A split keeps a SUBMITTED report in the "Awaiting approval" section but changes its reimbursable total
+    // (e.g. split to a lower amount). Home reads that total from the cached snapshot, which is only refreshed
+    // online, so patch the same-currency delta optimistically. `changesInReportTotal` is the signed report-total
+    // delta (new split total minus the pre-split total) in the transaction currency.
+    const yourSpendSplitUpdates = getYourSpendSnapshotSplitUpdates({
+        iouReport: expenseReport,
+        originalTransaction,
+        reimbursableDiff: changesInReportTotal,
+        currentUserAccountID: currentUserPersonalDetails.accountID,
+    });
+    onyxData.optimisticData?.push(...yourSpendSplitUpdates.optimisticData);
+    onyxData.successData?.push(...yourSpendSplitUpdates.successData);
+    onyxData.failureData?.push(...yourSpendSplitUpdates.failureData);
+
     if (isReverseSplitOperation) {
         const parameters = {
             ...splits.at(0),

src/libs/actions/IOU/YourSpendSnapshotUpdate.ts

@@ -411,4 +411,43 @@ function getYourSpendSnapshotTotalUpdates({transaction, updatedTransaction, iouR
     return result;
 }
 
-export {getYourSpendSnapshotReportMoveUpdates, getYourSpendSnapshotTotalUpdates, getYourSpendSnapshotTransactionRemovalUpdates, transactionMatchesAwaitingApprovalQuery};
+type GetYourSpendSnapshotSplitUpdatesParams = {
+    iouReport: OnyxEntry<Report>;
+    originalTransaction: OnyxEntry<Transaction>;
+    // Signed change to the report's reimbursable total, in the transaction/report currency
+    // (new split total minus the pre-split total). Negative when the expense is split to a lower amount.
+    reimbursableDiff: number;
+    currentUserAccountID: number;
+};
+
+/**
+ * Optimistically patches the "Awaiting approval" snapshot total when a SUBMITTED expense is split and the resulting
+ * reimbursable total changes (e.g. split to a lower amount). The report stays in the awaiting-approval section, so this
+ * is a same-section amount delta rather than a state move. Home reads totals from `snapshot.search.total`, which is only
+ * refreshed online. Mirrors the amount-edit path: same-currency only (the currency guard in
+ * `buildSnapshotTotalUpdatesForHash` skips a mismatch, since FX conversion isn't available offline).
+ */
+function getYourSpendSnapshotSplitUpdates({iouReport, originalTransaction, reimbursableDiff, currentUserAccountID}: GetYourSpendSnapshotSplitUpdatesParams): YourSpendSnapshotOnyxData {
+    const result: YourSpendSnapshotOnyxData = {optimisticData: [], successData: [], failureData: []};
+    if (!iouReport || !originalTransaction || reimbursableDiff === 0) {
+        return result;
+    }
+
+    const paidGroupPolicyIDs = getPaidGroupPolicyIDs();
+    if (!transactionMatchesAwaitingApprovalQuery(iouReport, originalTransaction, currentUserAccountID, paidGroupPolicyIDs)) {
+        return result;
+    }
+
+    const currency = getCurrency(originalTransaction);
+    const approvalQueryJSON = buildSearchQueryJSON(buildAwaitingApprovalQuery(currentUserAccountID, paidGroupPolicyIDs));
+    mergeYourSpendSnapshotOnyxData(result, buildSnapshotTotalUpdatesForHash(approvalQueryJSON?.hash, reimbursableDiff, currency));
+    return result;
+}
+
+export {
+    getYourSpendSnapshotReportMoveUpdates,
+    getYourSpendSnapshotSplitUpdates,
+    getYourSpendSnapshotTotalUpdates,
+    getYourSpendSnapshotTransactionRemovalUpdates,
+    transactionMatchesAwaitingApprovalQuery,
+};