[CLEAN] Synthetic Benchmark PR #63738 - Split expense flow (Phase 2 - Editing existing split expenses)

[tomerqodo]

User description

Benchmark PR Expensify#63738

Type: Clean (correct implementation)

Original PR Title: Split expense flow (Phase 2 - Editing existing split expenses)
Original PR Description: Split expense flow (Phase 2 - Editing existing split expenses)

Explanation of Change

Fixed Issues

$ Expensify#61028
$ Expensify#70481
$ Expensify#69371

PROPOSAL: NA

Tests

0. Enable newDotUpdateSplits beta
1. Navigate to an eligible expense in your reports or expenses list.
2. Open the More menu.
3. Click the Split button.
4. Save the splits.
5. Open the created split transaction.
6. Verify that the amount label contains the word “Split.”
7. Open the More menu.
8. Verify that “Edit splits” is displayed instead of “Split”
9. Click the Edit splits button or click the amount.
10. Verify that the split UI appears with the “Edit splits” header.
11. Verify that the split item from which the split expense was opened is selected.
12. Click on any split.
13. Verify that the Report menu item is displayed with the current report name (Report menu item is not editable).
14. Make some changes and save the splits.
15. Verify that the splits have been updated correctly, with messages confirming the changes to split data (amount, description, tag, etc.).

• Verify that no errors appear in the JS console

Offline tests

QA Steps

// TODO: These must be filled out, or the issue title must include "[No QA]."

0. Enable newDotUpdateSplits beta
1. Navigate to an eligible expense in your reports or expenses list.
2. Open the More menu.
3. Click the Split button.
4. Save the splits.
5. Open the created split transaction.
6. Verify that the amount label contains the word “Split.”
7. Open the More menu.
8. Verify that “Edit splits” is displayed instead of “Split”
9. Click the Edit splits button or click the amount.
10. Verify that the split UI appears with the “Edit splits” header.
11. Verify that the split item from which the split expense was opened is selected.
12. Click on any split.
13. Verify that the Report menu item is displayed with the current report name (Report menu item is not editable).
14. Make some changes and save the splits.
15. Verify that the splits have been updated correctly, with messages confirming the changes to split data (amount, description, tag, etc.).

• Verify that no errors appear in the JS console

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
  • MacOS: Desktop
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I verified there are no new alerts related to the canBeMissing param for useOnyx
• I followed proper code patterns (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text shown in the product is localized by adding it to src/languages/* files and using the translation method
    • If any non-english text was added/modified, I used JaimeGPT to get English > Spanish translation. I then posted it in #expensify-open-source and it was approved by an internal Expensify engineer. Link to Slack message:
  • I verified all numbers, amounts, dates and phone numbers shown in the product are using the localization methods
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • I verified the JSDocs style guidelines (in STYLE.md) were followed
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
• I verified any variables that can be defined as constants (ie. in CONST.ts or at the top of the file that uses the constant) are defined as such
• I verified that if a function's arguments changed that all usages have also been updated correctly
• If any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If new assets were added or existing ones were modified, I verified that:
  • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
  • The assets load correctly across all supported platforms.
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• If a new page is added, I verified it's using the ScrollView component to make it scrollable when more elements are added to the page.
• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

2025-09-29.16.52.42.mov

Android: mWeb Chrome

2025-09-29.16.52.42.mov

iOS: Native

2025-09-29.16.52.42.mov

iOS: mWeb Safari

2025-09-29.16.52.42.mov

MacOS: Chrome / Safari

2025-09-29.16.52.42.mov

MacOS: Desktop

2025-09-29.16.52.42.mov

**Original PR URL**: https://github.com/Expensify/pull/63738

---

PR Type

Enhancement

---

Description

• Enable editing of existing split expenses with full transaction modification support

• Add reverse split operation to consolidate multiple splits back into single expense

• Implement beta feature flags for split expense creation and editing workflows

• Add validation to prevent editing of approved or paid split expenses

• Enhance split transaction data model with merchant, status, and report tracking

---

Diagram Walkthrough

flowchart LR
  A["Split Expense Creation"] --> B["Store Split Data"]
  B --> C["Edit Split Expense"]
  C --> D{Beta Enabled?}
  D -->|Yes| E["Allow Editing"]
  D -->|No| F["Show Not Found"]
  E --> G{Approved/Paid?}
  G -->|Yes| H["Show Modal - Cannot Edit"]
  G -->|No| I["Enable Amount/Details Edit"]
  I --> J["Save Changes"]
  J --> K{Single Split?}
  K -->|Yes| L["Reverse Split Operation"]
  K -->|No| M["Update Split Transaction"]
  L --> N["Consolidate to Original"]
  M --> O["Update Child Transactions"]

Loading

File Walkthrough

	Relevant files
Enhancement	20 files IOU.ts Core split expense editing and creation logic                        +280/-149 ReportSecondaryActionUtils.ts Add beta flag support for split action visibility                +13/-6    index.ts Add child transaction retrieval utility function                  +23/-2    types.ts Add UPDATE_SPLIT_TRANSACTION API command                                  +2/-0      index.ts Add styles for non-editable split input display                    +15/-0    ReportUtils.ts Add transactionID to transaction details and improve report action linking +3/-1      DebugUtils.ts Add splitExpensesTotal validation for transaction drafts  +2/-0      SplitTransactionParams.ts Extend split transaction parameters with new fields            +8/-7      types.ts Replace isTransactionLinked with isEditable flag                  +2/-2      IOU.ts Extend SplitExpense type with merchant and report data      +9/-0      Transaction.ts Add splitExpensesTotal field to transaction comments          +3/-0      SplitExpensePage.tsx Implement split editing UI with validation and non-editable state +100/-12 MoneyRequestView.tsx Add split editing capability to money request view              +32/-12  SplitListItem.tsx Display non-editable split items with read-only amount display +65/-40  SplitExpenseEditPage.tsx Add report name display and beta feature gating                    +20/-4    MoneyReportHeader.tsx Update split action label based on expense split status    +7/-2      MoneyRequestHeader.tsx Add split editing support to transaction header                    +16/-3    index.native.tsx Use CHARACTER_WIDTH constant for prefix padding                    +1/-1      index.tsx Use CHARACTER_WIDTH constant for prefix padding                    +1/-1      MoneyRequestConfirmationList.tsx Use CHARACTER_WIDTH constant for amount input width            +1/-1
Documentation	10 files en.ts Add translation strings for split editing UI                          +4/-0      pl.ts Polish translations for split editing features                      +4/-0      ja.ts Japanese translations for split editing features                  +4/-0      it.ts Italian translations for split editing features                    +4/-0      de.ts German translations for split editing features                      +4/-0      nl.ts Dutch translations for split editing features                        +4/-0      fr.ts French translations for split editing features                      +4/-0      pt-BR.ts Portuguese translations for split editing features              +4/-0      es.ts Spanish translations for split editing features                    +4/-0      zh-hans.ts Chinese translations for split editing features                    +4/-0
Configuration changes	1 files index.ts Add beta feature flags and character width constant            +3/-0
Additional files	1 files IOUTest.ts +0/-1

---

[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
🟢	No security concerns identified No security vulnerabilities detected by AI analysis. Human verification advised for critical code.
Ticket Compliance
⚪	🎫 No ticket provided Create ticket/issue
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
⚪	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Missing audit logs: The new split-expense creation/update flows (e.g., saving, updating, or deleting child transactions) add significant state changes but introduce no explicit auditing/logging, making it unclear whether these critical actions are captured by an audit trail elsewhere. Referred Code const originalTransactionID = draftTransaction?.comment?.originalTransactionID ?? CONST.IOU.OPTIMISTIC_TRANSACTION_ID; const originalTransaction = allTransactions?.[`${ONYXKEYS.COLLECTION.TRANSACTION}${originalTransactionID}`]; const originalTransactionDetails = getTransactionDetails(originalTransaction); const iouActions = getIOUActionForTransactions([originalTransactionID], expenseReport?.reportID); const policyTags = getPolicyTagsData(expenseReport?.policyID); const participants = getMoneyRequestParticipantsFromReport(expenseReport); const splitExpenses = draftTransaction?.comment?.splitExpenses ?? []; // List of all child transactions that have been created after split const originalChildTransactions = getChildTransactions(originalTransactionID); const isCreationOfSplits = originalChildTransactions.length === 0; const processedChildTransactionIDs: string[] = []; const reportTotal = transactionReport?.total ?? 0; const splitExpensesTotal = draftTransaction?.comment?.splitExpensesTotal ?? 0; const isReverseSplitOperation = splitExpenses.length === 1 && originalChildTransactions.length > 0; let changesInReportTotal = 0; ... (clipped 294 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Edge cases unhandled: The split update path computes and uses report totals and performs multi-entity updates without visible safeguards for race conditions or missing entities (e.g., missing child transactions or reports), and lacks explicit error handling in case API calls fail beyond optimistic Onyx updates. Referred Code const originalChildTransactions = getChildTransactions(originalTransactionID); const isCreationOfSplits = originalChildTransactions.length === 0; const processedChildTransactionIDs: string[] = []; const reportTotal = transactionReport?.total ?? 0; const splitExpensesTotal = draftTransaction?.comment?.splitExpensesTotal ?? 0; const isReverseSplitOperation = splitExpenses.length === 1 && originalChildTransactions.length > 0; let changesInReportTotal = 0; // Validate custom unit rate before proceeding with split const customUnitRateID = originalTransaction?.comment?.customUnit?.customUnitRateID; const isPerDiem = isPerDiemRequestTransactionUtils(originalTransaction); if (customUnitRateID && policy && !isPerDiem) { const customUnitRate = getDistanceRateCustomUnitRate(policy, customUnitRateID); // If the rate doesn't exist or is disabled, show an error and return early if (!customUnitRate || !customUnitRate.enabled) { // Show error to user Onyx.merge(`${ONYXKEYS.COLLECTION.SPLIT_TRANSACTION_DRAFT}${originalTransactionID}`, { ... (clipped 187 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Params sanitization: SplitTransaction parameters dynamically serialize nested fields to strings for API submission without visible validation/sanitization of user-modifiable fields (e.g., comment, merchant), which may rely on upstream sanitization not shown in this diff. Referred Code import type {Comment} from '@src/types/onyx/Transaction'; type SplitTransactionSplitsParam = Array<{ amount: number; transactionID: string; category?: string; tag?: string; created: string; merchant?: string; comment?: Comment; splitReportActionID?: string; transactionThreadReportID?: string; createdReportActionIDForThread?: string; modifiedExpenseReportActionID?: string; reimbursable?: boolean; billable?: boolean; reportID?: string; }>; type SplitTransactionParams = { transactionID: string; ... (clipped 3 lines) Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
High-level	Simplify client-side logic for splits The client-side saveSplitTransactions function is overly complex, handling creation, updates, and deletions of split transactions. This logic should be moved to a single backend endpoint that receives the desired final state of all splits. Examples: src/libs/actions/IOU.ts [13004-13330] function saveSplitTransactions( draftTransaction: OnyxEntry<OnyxTypes.Transaction>, hash: number, policyCategories: OnyxTypes.PolicyCategories | undefined, policy: OnyxTypes.Policy | undefined, ) { const transactionReport = getReportOrDraftReport(draftTransaction?.reportID); const parentTransactionReport = getReportOrDraftReport(transactionReport?.parentReportID); const expenseReport = transactionReport?.type === CONST.REPORT.TYPE.EXPENSE ? transactionReport : parentTransactionReport; ... (clipped 317 lines) Solution Walkthrough: Before: function saveSplitTransactions(draftTransaction) { // ... complex setup ... const originalChildTransactions = getChildTransactions(originalTransactionID); const isCreationOfSplits = originalChildTransactions.length === 0; // Loop through each desired split from the UI splitExpenses.forEach((splitExpense) => { const existingTransaction = findExistingTransaction(splitExpense.transactionID); if (existingTransaction) { // Logic to calculate diffs and prepare for an UPDATE const { onyxData } = getUpdateMoneyRequestParams(...); optimisticData.push(...onyxData.optimisticData); } else { // Logic to prepare for a CREATE const { onyxData } = getMoneyRequestInformation(...); optimisticData.push(...onyxData.optimisticData); } }); // Logic to find and prepare for DELETING splits // ... // Call different APIs based on context if (isCreationOfSplits) { API.write('SplitTransaction', ...); } else { API.write('UpdateSplitTransaction', ...); } } After: function saveSplitTransactions(draftTransaction) { // 1. Get the final desired state of splits from the UI draft. const desiredSplits = draftTransaction.comment.splitExpenses.map(split => ({ transactionID: split.transactionID, // Can be existing or temporary amount: split.amount, description: split.description, // ... other fields })); // 2. Prepare optimistic data for the UI. // This is now much simpler, as it just reflects the final state. const optimisticData = buildOptimisticSplitUpdate(originalTransactionID, desiredSplits); // 3. Send the complete list to a single, robust backend endpoint. const parameters = { originalTransactionID, splits: desiredSplits, }; API.write('SaveTransactionSplits', parameters, { optimisticData, ... }); } Suggestion importance[1-10]: 9 __ Why: The suggestion correctly identifies that the saveSplitTransactions function has become overly complex by managing the logic for creating, updating, and deleting splits on the client, and proposes a valid architectural simplification by moving this responsibility to the backend.	High
Possible issue	Correct logic for removing splits Change the condition for showing the "Remove split" button from > 2 to > 1 to allow users to reduce the number of splits to one. src/pages/iou/SplitExpenseEditPage.tsx [215-235] <FixedFooter style={styles.mtAuto}> - {Number(splitExpensesList?.length) > 2 && ( + {Number(splitExpensesList?.length) > 1 && ( <Button danger large style={[styles.w100, styles.mb4]} onPress={() => { removeSplitExpenseField(draftTransaction, splitExpenseTransactionID); Navigation.goBack(backTo); }} text={translate('iou.removeSplit')} /> )} <Button success large style={[styles.w100]} onPress={() => { updateSplitExpenseField(splitExpenseDraftTransaction, splitExpenseTransactionID); Navigation.goBack(backTo); }} text={translate('common.save')} /> </FixedFooter> [To ensure code accuracy, apply this suggestion manually] Suggestion importance[1-10]: 7 __ Why: The suggestion correctly fixes a bug where a user cannot remove a split when there are only two, by changing the condition from > 2 to > 1.	Medium
General	Prioritize zero-amount validation for splits Move the validation for zero-amount splits to the beginning of the onSaveSplitExpense function to provide earlier feedback to the user. src/pages/iou/SplitExpensePage.tsx [112-173] const onSaveSplitExpense = useCallback(() => { + if (splitExpenses.find((item) => item.amount === 0)) { + setErrorMessage(translate('iou.splitExpenseZeroAmount')); + return; + } + if (splitExpenses.length <= 1 && (!childTransactions.length || !isBetaEnabled(CONST.BETAS.NEWDOT_REVERT_SPLITS))) { const splitFieldDataFromOriginalTransactionWithoutID = {...splitFieldDataFromOriginalTransaction, transactionID: ''}; const splitExpenseWithoutID = {...splitExpenses.at(0), transactionID: ''}; // When we try to save one split during splits creation and if the data is identical to the original transaction we should close the split flow if (!childTransactions.length && deepEqual(splitFieldDataFromOriginalTransactionWithoutID, splitExpenseWithoutID)) { Navigation.dismissModal(); return; } // When we try to save splits during editing splits and if the data is identical to the already created transactions we should close the split flow if (childTransactions.length && deepEqual(splitFieldDataFromChildTransactions, splitExpenses)) { Navigation.dismissModal(); return; } // When we try to save one split during splits creation and if the data is not identical to the original transaction we should show the error setErrorMessage(translate('iou.splitExpenseOneMoreSplit')); return; } if (draftTransaction?.errors) { clearSplitTransactionDraftErrors(transactionID); } if (sumOfSplitExpenses > Math.abs(transactionDetailsAmount)) { const difference = sumOfSplitExpenses - Math.abs(transactionDetailsAmount); setErrorMessage(translate('iou.totalAmountGreaterThanOriginal', {amount: convertToDisplayString(difference, transactionDetails?.currency)})); return; } if (sumOfSplitExpenses < Math.abs(transactionDetailsAmount) && (isPerDiem || isCard)) { const difference = Math.abs(transactionDetailsAmount) - sumOfSplitExpenses; setErrorMessage(translate('iou.totalAmountLessThanOriginal', {amount: convertToDisplayString(difference, transactionDetails?.currency)})); return; } - if (splitExpenses.find((item) => item.amount === 0)) { - setErrorMessage(translate('iou.splitExpenseZeroAmount')); - return; - } - // When we try to save splits during editing splits and if the data is identical to the already created transactions we should close the split flow if (deepEqual(splitFieldDataFromChildTransactions, splitExpenses)) { Navigation.dismissModal(); return; } saveSplitTransactions(draftTransaction, currentSearchHash, policyCategories, expenseReportPolicy); }, [ splitExpenses, childTransactions.length, isBetaEnabled, draftTransaction, sumOfSplitExpenses, transactionDetailsAmount, isPerDiem, isCard, splitFieldDataFromChildTransactions, currentSearchHash, policyCategories, expenseReportPolicy, splitFieldDataFromOriginalTransaction, translate, transactionID, transactionDetails?.currency, ]); Apply / Chat Suggestion importance[1-10]: 4 __ Why: The suggestion correctly proposes reordering validation checks to fail-fast on zero-amount splits, which improves user experience and is a good practice.	Low
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