[Due for payment 2025-11-10][$250] Merge expenses - Merging transactions triggers `canBeMissing` errors

[izarutskaya]

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Version Number: 9.2.37-8
Reproducible in staging?: Yes
Reproducible in production?: Yes
If this was caught during regression testing, add the test name, ID and link from TestRail:
Email or phone of affected tester (no customers):
Logs: https://stackoverflow.com/c/expensify/questions/4856
Expensify/Expensify Issue URL:
Issue reported by: @QichenZhu
Slack conversation (hyperlinked to channel name): #expensify_bugs

Action Performed:

Precondition: At least 2 expenses in self DM.

1. Go to https://staging.new.expensify.com/
2. Open an expense in self DM
3. Tap More > Merge
4. Select another expense and Continue
5. Choose any details and Continue
6. Tap Merge expenses

Expected Result:

No canBeMissing errors in the console.

Actual Result:

There are two canBeMissing console errors:

1. [Onyx] useOnyx returned no data for key with canBeMissing set to false for key policy_undefined
2. [Onyx] useOnyx returned no data for key with canBeMissing set to false for key mergeTransaction_4792941280298311116

Workaround:

Can the user still use Expensify without this being fixed? Have you informed them of the workaround?

Platforms:

Select the officially supported platforms where the issue was reproduced:

• Android: App
• Android: mWeb Chrome
• iOS: App
• iOS: mWeb Safari
• iOS: mWeb Chrome
• Windows: Chrome
• MacOS: Chrome / Safari
• MacOS: Desktop

Platforms Tested:

On which of our officially supported platforms was this issue tested:

• Android: App
• Android: mWeb Chrome
• iOS: App
• iOS: mWeb Safari
• iOS: mWeb Chrome
• Windows: Chrome
• MacOS: Chrome / Safari
• MacOS: Desktop

Screenshots/Videos

Recording.3470.mp4

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• Upwork Job URL: https://www.upwork.com/jobs/~021981795318329571536
• Upwork Job ID: 1981795318329571536
• Last Price Increase: 2025-10-24

Issue Owner

Current Issue Owner: @lschurr

[melvin-bot]

Triggered auto assignment to @lschurr (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[ryntgh]

Proposal

Please re-state the problem that we are trying to solve in this issue.

Merge expenses - Merging transactions triggers canBeMissing errors

What is the root cause of that problem?

The policy useOnyx hook has canBeMissing: false but accesses report?.policyID which could be undefined, creating a key like policy_undefined

App/src/pages/TransactionMerge/MergeTransactionsListContent.tsx

Line 53 in a77718d

const [policy] = useOnyx(`${ONYXKEYS.COLLECTION.POLICY}${report?.policyID}`, {canBeMissing: false});

Then for mergeTransaction, multiple files access merge transaction data with canBeMissing: false

App/src/pages/TransactionMerge/MergeTransactionsListPage.tsx

Line 22 in a77718d

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

App/src/pages/TransactionMerge/DetailsReviewPage.tsx

Line 53 in a77718d

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

App/src/pages/TransactionMerge/ReceiptReviewPage.tsx

Line 34 in a77718d

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

What changes do you think we should make in order to solve the problem?

We need to update it to use canBeMissing: true

What alternative solutions did you explore? (Optional)

N/A

[mkzie2]

Proposal

Please re-state the problem that we are trying to solve in this issue.

There are two canBeMissing console errors:

What is the root cause of that problem?

Report?.policyID can be missing here which then make the key become policy_undefined. Thus, causes Onyx to throw an error

App/src/pages/TransactionMerge/MergeTransactionsListContent.tsx

Line 53 in 9a70acd

const [policy] = useOnyx(`${ONYXKEYS.COLLECTION.POLICY}${report?.policyID}`, {canBeMissing: false});

Then makes these call err as well

App/src/pages/TransactionMerge/DetailsReviewPage.tsx

Line 53 in ef68662

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

App/src/pages/TransactionMerge/MergeTransactionsListPage.tsx

Line 22 in fa5e06d

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

App/src/pages/TransactionMerge/ReceiptReviewPage.tsx

Line 34 in ef68662

const [mergeTransaction, mergeTransactionMetadata] = useOnyx(`${ONYXKEYS.COLLECTION.MERGE_TRANSACTION}${transactionID}`, {canBeMissing: false});

App/src/pages/TransactionMerge/ConfirmationPage.tsx

Lines 60 to 62 in b951177

	const [policy] = useOnyx(`${ONYXKEYS.COLLECTION.POLICY}${policyID}`, {canBeMissing: true});
	const [policyTags] = useOnyx(`${ONYXKEYS.COLLECTION.POLICY_TAGS}${policyID}`, {canBeMissing: true});
	const [policyCategories] = useOnyx(`${ONYXKEYS.COLLECTION.POLICY_CATEGORIES}${policyID}`, {canBeMissing: true});

What changes do you think we should make in order to solve the problem?

We need to prevent the useOnyx call from being made with an undefined key by using getNonEmptyStringOnyxID like what we did in many places such as here as well as update canBeMissing to true

What specific scenarios should we cover in automated tests to prevent reintroducing this issue in the future?

NA

What alternative solutions did you explore? (Optional)

Reminder: Please use plain English, be brief and avoid jargon. Feel free to use images, charts or pseudo-code if necessary. Do not post large multi-line diffs or write walls of text. Do not create PRs unless you have been hired for this job.

[melvin-bot]

Job added to Upwork: https://www.upwork.com/jobs/~021981795318329571536

[melvin-bot]

Triggered auto assignment to Contributor-plus team member for initial proposal review - @bernhardoj (External)

[bernhardoj]

@ryntgh is the first one to suggest setting canBeMissing to true, so let's go with his proposal.

🎀 👀 🎀 C+ reviewed

Btw, the merge confirmation page is currently infinitely loading. I've reported the bug here. To temporarily fix it, you can replace targetTransaction?.reportID with getReportIDForExpense(targetTransaction). It's now fixed.

App/src/pages/TransactionMerge/ConfirmationPage.tsx

Line 54 in bceff96

const [targetTransactionThreadReportID] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${targetTransaction?.reportID}`, {