Merge pull request #93294 from Expensify/claude-fixSplitDistanceMileageRate

Author: mjasikowski

src/libs/actions/IOU/MoneyRequest.ts

@@ -407,6 +407,10 @@ function startMoneyRequest(
     isFromFloatingActionButton?: boolean,
 ) {
     const sourceRoute = Navigation.getActiveRoute();
+    // Only the split flow exposes a Distance tab from here, so prefetch the default P2P mileage rate solely for splits to avoid an unnecessary read on other flows.
+    if (iouType === CONST.IOU.TYPE.SPLIT) {
+        getDefaultP2PMileageRate();
+    }
     startSpan(CONST.TELEMETRY.SPAN_OPEN_CREATE_EXPENSE, {
         name: '/money-request-create',
         op: CONST.TELEMETRY.SPAN_OPEN_CREATE_EXPENSE,

tests/unit/DefaultP2PMileageRateTest.ts

@@ -1,4 +1,5 @@
 import Onyx from 'react-native-onyx';
+import {startMoneyRequest} from '@libs/actions/IOU/MoneyRequest';
 import {getDefaultP2PMileageRate} from '@libs/actions/Transaction';
 import * as API from '@libs/API';
 import {READ_COMMANDS} from '@libs/API/types';
@@ -9,6 +10,9 @@ import ONYXKEYS from '@src/ONYXKEYS';
 import createRandomTransaction from '../utils/collections/transaction';
 import waitForBatchedUpdates from '../utils/waitForBatchedUpdates';
 
+jest.mock('@libs/Navigation/Navigation');
+jest.mock('@libs/telemetry/activeSpans');
+
 describe('Default P2P mileage rate', () => {
     beforeAll(() => {
         Onyx.init({
@@ -34,6 +38,29 @@ describe('Default P2P mileage rate', () => {
         });
     });
 
+    describe('startMoneyRequest', () => {
+        // Splitting a distance expense goes through startMoneyRequest, so it must prefetch the default P2P mileage rate
+        // (the same way startDistanceRequest does) or the Distance tab loads with a malformed rate.
+        it('prefetches the default P2P mileage rate when starting a split distance request', () => {
+            // eslint-disable-next-line rulesdir/no-multiple-api-calls
+            const readSpy = jest.spyOn(API, 'read').mockImplementation(() => {});
+
+            startMoneyRequest(CONST.IOU.TYPE.SPLIT, '1', [], CONST.IOU.REQUEST_TYPE.DISTANCE);
+
+            expect(readSpy).toHaveBeenCalledWith(READ_COMMANDS.GET_DEFAULT_P2P_MILEAGE_RATE, null);
+        });
+
+        // Non-split flows never expose a Distance tab, so they must not issue the (uncached) prefetch read.
+        it('does not prefetch the default P2P mileage rate for non-split requests', () => {
+            // eslint-disable-next-line rulesdir/no-multiple-api-calls
+            const readSpy = jest.spyOn(API, 'read').mockImplementation(() => {});
+
+            startMoneyRequest(CONST.IOU.TYPE.SUBMIT, '1', [], CONST.IOU.REQUEST_TYPE.MANUAL);
+
+            expect(readSpy).not.toHaveBeenCalledWith(READ_COMMANDS.GET_DEFAULT_P2P_MILEAGE_RATE, null);
+        });
+    });
+
     describe('getRateForP2P', () => {
         it('falls back to USD 67¢/mile when no rate has been stored in Onyx', () => {
             const result = DistanceRequestUtils.getRateForP2P('EUR', undefined);