fix: skip auto-redistribution when adding splits with manual edits by ikevin127 · Pull Request #87124 · Expensify/App

ikevin127 · 2026-04-04T03:17:55Z

Explanation of Change

When a user manually edits split amounts and then adds a new split, the previous logic would auto-redistribute amounts among unedited splits. This caused incorrect calculations when the manually edited amount exceeded the total (e.g., editing a -$10 split to -$20 and adding a new split).

Now, new splits start at $0.00 when manual edits exist, allowing users to fully control the distribution.

Fixed Issues

$ #82455
PROPOSAL:

Tests

Open a workspace chat in the app.
Create an expense with amount -$10.00 (negative).
Open the expense report and tap More > Split.
Edit the first split amount to -$20.00 (more than total).
Save the split.
Open any of the 2 generated splits and tap on the Amount field.
Tap Add split to create a new split.
Verify: The newly created split amount is $0.00.
Verify: The first split remains -$20.00.
Verify: When pressing Save, user gets 🔴 Please enter a valid amount before continuing. validation error.

Warning

Note that the auto-redistribution issues caused by editing previously existing splits AFTER adding the new ones are out of scope for this PR as mentioned here.

Verify that no errors appear in the JS console

Offline tests

N/A

QA Steps

Same as tests.

Verify that no errors appear in the JS console

PR Author Checklist

Screenshots/Videos

Screen.Recording.2026-04-03.at.19.30.58.mov

melvin-bot · 2026-04-04T03:18:03Z

@ShridharGoel Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

ShridharGoel · 2026-04-04T11:27:13Z

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Screenshots/Videos

Android: HybridApp

Screen.Recording.2026-04-04.at.5.00.33.PM.mov

Android: mWeb Chrome

Screen.Recording.2026-04-04.at.5.07.17.PM.mov

iOS: HybridApp

Screen.Recording.2026-04-04.at.5.12.25.PM.mov

iOS: mWeb Safari

Screen.Recording.2026-04-04.at.5.13.41.PM.mov

MacOS: Chrome / Safari

Screen.Recording.2026-04-04.at.4.54.03.PM.mov

ShridharGoel · 2026-04-04T11:42:11Z

@ikevin127 Isn't the auto-distribution wrong here?

Screen.Recording.2026-04-04.at.5.10.22.PM.mov

ikevin127 · 2026-04-04T11:47:51Z

Not sure, is this something that differs from current staging behaviour (meaning it only happens on this PR) ?

If yes, could you please provide some minimal steps for how you reached the scenario in the video and the exected / actual result ? Would help with debugging 🙌

Aside: AFAIK we didn't have auto-redistribution on the Edit split page - but that might've been added in the meantime by somebody else.

ShridharGoel · 2026-04-04T12:07:19Z

I think we can't compare with staging since there the total is wrong from the beginning itself (the issue that we are fixing in this PR). So, even after changing one of the newly added splits, the total isn't correct there.

Staging video:

Screen.Recording.2026-04-04.at.5.36.38.PM.mov

Steps:

Open a workspace chat in the app.
Create an expense with amount -$10.00 (negative).
Open the expense report and tap More > Split.
Edit the first split amount to -$20.00 (more than total).
Save the split.
Open any of the 2 generated splits and tap on the Amount field.
Tap Add split to create a new split.
Click Add split again.
Edit one of the old splits.
Notice that the auto-distributed values don't sum up to the original total.

ikevin127 · 2026-04-05T06:07:50Z

@ShridharGoel Looked into it, what you're seeing is a previously existing logic bug (verifiable on staging as well).

The fix I applied is working somewhat correctly, but after taking a second look at it - it's a bit too broad, blocking any auto-redistributions (keeps amount at 0) whenever any of the other existing splits were previously edited manually - this is wrong given our issue's expected result:

The new split amount will be 0.00 as it redistributes to match the total amount.

I think the expected in the OP is what we want. Using the example:

Original expense is -10

Splits are created: A = -20 so B = 10 to equal -10

When a new split, C, is created, it should default to 0 since A and B already equal the original amount.

🔄 Reworking the solution to make sure the new split will be 0 only when the other existing splits are already equal to the total amount. Will try to also find a fix for the staging bug you pointed out where existing negative amount total is flipping to positive amount whenever new splits are added / updated / removed.

ikevin127 · 2026-04-05T09:28:42Z

@ShridharGoel Update:

reworked solution for our issue (the one this PR was opened for) such that when the other existing splits are already equal to the total amount, newly added splits will be 0 ✅

☝️ This works only for the initial addition of new splits, if you adjust some of the initial splits: the issues you mentioned here and here will occur just like on current staging (which is out of scope for this PR).

🟢 Applied reworked solution and adjusted tests.

ikevin127 · 2026-04-05T09:29:19Z

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chatgpt-codex-connector · 2026-04-05T09:37:40Z

src/libs/actions/IOU/Split.ts

    // Auto-redistribute amounts for all splits if this is not a distance request
-    if (!isDistanceRequest) {
+    // Skip redistribution if existing splits already match the total (new split stays at 0)
+    if (!isDistanceRequest && !splitsAlreadyMatchTotal) {


Limit redistribution skip to manually edited splits

addSplitExpenseField now bypasses redistribution whenever existing splits already sum to the transaction total, but that condition is true for normal unedited splits as well. In a common flow (for example, two unedited 50/50 splits), adding a new split will now keep amounts as 500, 500, 0 instead of rebalancing across all unedited splits, which regresses the expected auto-adjust behavior described in this module and user flow. The skip condition should be tied to manual-edit state, not just sum equality.

Useful? React with 👍 / 👎.

Correct, this would regress the initial split scenario when none of the splits were manually edited yet and we add new splits - will apply fix shortly.

ikevin127 · 2026-04-05T10:11:06Z

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chatgpt-codex-connector · 2026-04-05T10:18:24Z

src/libs/actions/IOU/Split.ts

+    // Check if existing splits already sum to the total
+    const existingSum = existingSplits.reduce((sum, split) => sum + split.amount, 0);
+    const hasManuallyEditedSplits = existingSplits.some((split) => split.isManuallyEdited);
+    const splitsAlreadyMatchTotal = Math.abs(existingSum) === Math.abs(total);


Compare split totals with sign before skipping redistribution

Using Math.abs(existingSum) === Math.abs(total) treats opposite-signed totals as a match, so a negative transaction can incorrectly skip redistribution when manually edited splits sum to the positive magnitude (for example, +1000 vs -1000). In that case shouldRedistribute becomes false, the added split stays at 0, and the draft remains unbalanced, which then blocks saving with validation errors; this regression is introduced by the new skip condition and can be avoided by checking signed equality instead of absolute equality.

Useful? React with 👍 / 👎.

This is intended, as using absolute values to check equality between splits sum amount and total transaction amount is the only reliable way that works for both positive and negative amounts ✅

codecov · 2026-04-05T10:18:29Z

Codecov Report

✅ Changes either increased or maintained existing code coverage, great job!

Files with missing lines	Coverage Δ
src/libs/actions/IOU/Split.ts	`80.51% <100.00%> (+0.08%)`	⬆️
... and 16 files with indirect coverage changes

ikevin127 added 2 commits April 3, 2026 20:07

fix: skip auto-redistribution when adding splits with manual edits

72e0bb9

chore: prettier

691cb5e

ikevin127 requested review from a team as code owners April 4, 2026 03:17

melvin-bot bot assigned ikevin127 Apr 4, 2026

melvin-bot bot requested review from ShridharGoel and joekaufmanexpensify and removed request for a team and joekaufmanexpensify April 4, 2026 03:18

fix: rework logic ♻️

2e30948

chatgpt-codex-connector bot reviewed Apr 5, 2026

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fix: limit redistribution skip to manually edited splits

58e67c5

chatgpt-codex-connector bot reviewed Apr 5, 2026

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ShridharGoel approved these changes Apr 5, 2026

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melvin-bot bot requested a review from blimpich April 5, 2026 11:10

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