Fix duplicate expense navigation arrows showing inverted state on first open

[MelvinBot]

Explanation of Change

When opening a duplicate expense from the "Review duplicates" screen, the navigation arrows (left/right) showed inverted state on the first open but correct state on the second open. This was caused by a race condition between two callers of setActiveTransactionIDs:

1. Review.tsx's onPreviewPressed sets the IDs to the duplicate-sorted order
2. MoneyRequestReportTransactionList's useEffect fires when visualOrderTransactionIDs gets a new reference (due to navigation-triggered re-renders) and overwrites the IDs with the parent report's visual sort order

This fix adds a guard to the useEffect in MoneyRequestReportTransactionList.tsx to skip setting active transaction IDs when the SEARCH_REPORT was opened from the duplicate review context (detected via the backTo route param). This matches the existing isFromReviewDuplicates pattern already used in MoneyRequestHeader.tsx.

Fixed Issues

$ #83751
PROPOSAL: #83751 (comment)

Tests

1. Go to staging.new.expensify.com
2. Go to workspace chat
3. Create two expenses with the same amount
4. Open the report
5. Click Review duplicates
6. Click on the second expense preview
7. Verify the left arrow is enabled and the right arrow is disabled (since this is the last expense)
8. Close the report RHP
9. Click on the second expense preview again
10. Verify the arrow state is the same as step 7

• Verify that no errors appear in the JS console

Offline tests

N/A - This change only affects navigation state during UI interaction and does not involve network requests.

QA Steps

1. Go to a workspace chat
2. Create two expenses with the same amount
3. Open the report
4. Click Review duplicates
5. Click on the second expense preview
6. Verify the left arrow is enabled and the right arrow is disabled
7. Close the report RHP
8. Click on the second expense preview again
9. Verify the arrow state is the same as step 6 (left enabled, right disabled)

• 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
• 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 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)
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  • 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:
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• 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
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Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

[MelvinBot]

I created this PR from an upstream branch since I don't have push access to your fork.

To take ownership of this branch and be able to push updates, run:

git remote add upstream https://github.com/Expensify/App.git
git fetch upstream claude-fixDuplicateExpenseArrowSequence
git checkout -b claude-fixDuplicateExpenseArrowSequence upstream/claude-fixDuplicateExpenseArrowSequence
git push -u origin claude-fixDuplicateExpenseArrowSequence

Then you can close this PR and open a new one from your fork.

[ChavdaSachin]

@MelvinBot current PR approach is not good enough,

I have two candidate approaches here, please analyze and do not make changes to the code yet.

Option 1 - As MoneyRequestReportTransactionList.tsx is already taking care of setting the active IDs, how about avoiding race condition by removing the setActiveTransactionIDs from review.tsx.

Option 2 - In Review.tsx sort siblingTransactionIDsList before passing it to setActiveTransactionIDs, the sorting logic should be similar to MoneyRequestReportTransactionList.tsx, and hence the array passed to the setActiveTransactionIDs is exactly same from both call sites.

[MelvinBot]

Thanks for the feedback ChavdaSachin. Here's a detailed analysis of both options:

---

Analysis of Option 1 — Remove setActiveTransactionIDs from Review.tsx

Verdict: This would break the duplicate review UX.

The two call sites operate on fundamentally different transaction sets:

	Review.tsx	MoneyRequestReportTransactionList.tsx
Transaction set	Duplicate sibling transactions (from DUPLICATED_TRANSACTION violation data)	All transactions on the report
Purpose	Navigate prev/next through duplicate siblings	Navigate prev/next through report expenses

When a user taps a duplicate in Review.tsx, onPreviewPressed builds siblingTransactionIDsList from the current transaction + its duplicates (sourced from violation data at Review.tsx:54-65), then navigates to SEARCH_REPORT. If we removed this call, MoneyRequestReportTransactionList's useEffect would set the active IDs to the report's full transaction list — the prev/next arrows would then cycle through all report expenses instead of through the duplicate siblings, which is incorrect behavior.

Additionally, Review.tsx has a restore mechanism (Review.tsx:71-97) — it saves the pre-existing transactionIDsList on first click and restores it via useFocusEffect when navigating back. Removing the setActiveTransactionIDs call would also break this restoration logic.

---

Analysis of Option 2 — Sort siblingTransactionIDsList in Review.tsx with the same logic as MoneyRequestReportTransactionList.tsx

Verdict: This doesn't solve the problem because the transaction sets differ, not just the sort order.

Even if Review.tsx used the same compareValues() sort logic from MoneyRequestReportTransactionList.tsx, the two callers would still produce different ID arrays for three reasons:

1. Different transaction sets: Review.tsx has duplicate sibling IDs (e.g., [txn_A, txn_B] — two duplicates), while MoneyRequestReportTransactionList has the full report's transaction IDs (e.g., [txn_A, txn_B, txn_C, txn_D]). Since the arrays have different elements, the idempotency check in setActiveTransactionIDs would still detect a mismatch and overwrite.

2. Grouping: MoneyRequestReportTransactionList can group transactions by category/tag (sorted alphabetically via sortGroupedTransactions in ReportLayoutUtils.ts:13-22), further reordering IDs. Review.tsx has no grouping concept.

3. User-configurable sort column: MoneyRequestReportTransactionList lets users sort by merchant, category, tag, amount, or description — not just date. Even if you aligned the default date sort, a user who previously sorted by amount would still get a different order.

---

Why the current PR approach (guard in useEffect) is the right direction

The core issue is that these two callers serve different navigation contexts:

• Review.tsx → "navigate between duplicate siblings"
• MoneyRequestReportTransactionList → "navigate between report expenses"

A guard that prevents one from overwriting the other is the architecturally correct solution. The backTo URL check in the current PR accurately detects the duplicate review context.

That said, if there are concerns about the fragility of URL string matching (backTo?.replaceAll(/\?.*/g, '').endsWith('/duplicates/review')), one alternative refinement could be using a more explicit signal — for example, passing a boolean flag through route params or using a context/ref that Review.tsx sets before navigation to indicate "I've already set the active IDs, don't overwrite."

[ChavdaSachin]

@MelvinBot do you have any other ideas here?
Remember do not change code without my explicit instructions.

[codecov]

Codecov Report

❌ Looks like you've decreased code coverage for some files. Please write tests to increase, or at least maintain, the existing level of code coverage. See our documentation here for how to interpret this table.

Files with missing lines	Coverage Δ
...stReportView/MoneyRequestReportTransactionList.tsx	1.31% <0.00%> (-0.02%)	⬇️
... and 10 files with indirect coverage changes

[MelvinBot]

Here are some alternative ideas, beyond the two options we already analyzed and the current PR's URL guard approach:

---

Idea 1 — Source-aware setActiveTransactionIDs (Recommended)

Add a source parameter to setActiveTransactionIDs in TransactionThreadNavigation.ts. Track the source in a module-level variable alongside the existing lastSetIDs. The rule: a 'reportList' write cannot overwrite a 'reviewDuplicates' write.

let lastSetIDs: string[] | null = null;
let lastSource: string | null = null;

function setActiveTransactionIDs(ids: string[], source: 'reportList' | 'reviewDuplicates' | 'searchList' = 'reportList') {
    if (lastSource === 'reviewDuplicates' && source === 'reportList') {
        return Promise.resolve();
    }
    if (lastSetIDs?.length === ids.length && lastSetIDs.every((id, i) => id === ids.at(i))) {
        return Promise.resolve();
    }
    lastSetIDs = ids;
    lastSource = source;
    return Onyx.set(ONYXKEYS.TRANSACTION_THREAD_NAVIGATION_TRANSACTION_IDS, ids);
}

function clearActiveTransactionIDs() {
    lastSetIDs = null;
    lastSource = null;
    return Onyx.set(ONYXKEYS.TRANSACTION_THREAD_NAVIGATION_TRANSACTION_IDS, null);
}

Then Review.tsx passes 'reviewDuplicates' as the source, and MoneyRequestReportTransactionList uses the default 'reportList'. The existing clearActiveTransactionIDs (called via cleanup effects when navigating away) naturally resets the lock.

Pros:

• Centralizes conflict resolution in the one module responsible for the state
• No URL string matching, no route param changes, no Onyx type changes
• All existing callers are unaffected (default source is 'reportList')
• Easy to reason about and extend to future callers
• TransactionGroupListExpanded.tsx (another caller using the same set-then-navigate pattern at line 111-120) would also work without changes

Cons:

• Module-level state only works within the same JS runtime (fine for React Native)

---

Idea 2 — Separate Onyx key for duplicate review context

Create ONYXKEYS.DUPLICATE_REVIEW_TRANSACTION_IDS. Review.tsx writes to this new key. MoneyRequestReportTransactionsNavigation (the consumer at line 36-37) reads both keys and prefers the duplicate key when non-null.

Pros: Eliminates the race entirely — the two contexts write to different keys.
Cons: More Onyx plumbing — new key, new cleanup logic, navigation component must merge/prioritize two sources.

---

Idea 3 — Conditional write: only set IDs if Onyx key is empty

Change the useEffect in MoneyRequestReportTransactionList to read the current Onyx value first (via useOnyx) and skip the write if IDs already exist.

Pros: Simple, minimal change.
Cons: Fragile — would prevent the useEffect from updating IDs when visualOrderTransactionIDs legitimately changes (e.g., a transaction is deleted while viewing). Also depends on cleanup ordering between components. I'd consider this weaker than the other two.

---

My recommendation

Idea 1 (source-aware setActiveTransactionIDs) is the cleanest approach. It solves the race condition at the right level of abstraction — the module that owns the state — without URL parsing, route param changes, or additional Onyx keys. The change is small (one module + one call site passes a source string), and the clearActiveTransactionIDs call already handles resetting when navigating away.

Let me know which direction you'd like to go and I'll implement it.

[mountiny]

I would prefer not to rely on the routes/ backTo

[ChavdaSachin]

Idea 2 — Separate Onyx key for duplicate review context
Create ONYXKEYS.DUPLICATE_REVIEW_TRANSACTION_IDS. Review.tsx writes to this new key. MoneyRequestReportTransactionsNavigation (the consumer at line 36-37) reads both keys and prefers the duplicate key when non-null.

Pros: Eliminates the race entirely — the two contexts write to different keys.
Cons: More Onyx plumbing — new key, new cleanup logic, navigation component must merge/prioritize two sources.

This one makes the most sense to me.

@mountiny should I prepare CP using this idea?

[ChavdaSachin]

Also could we add "help wanted" label back, in case someone has a better idea.

[mountiny]

I might have one from Claude

[mountiny]

@ChavdaSachin let me know what you think #83772