Revert "perf: defer the split-save API.write behind the destination layout"

[Abdukhamid000]

Reverts #98012

Explanation of Change

Deploy blocker on staging 9.4.64-0. #98012 deferred the split-save write behind a navigation transition barrier when isFromSplitExpensesFlow is set - which is exactly the flag the Search exit passes.

Reads block on waitForWrites() -> SequentialQueue.waitForIdle(), and that gate is only claimed when a write is actually pushed. With the write deferred, nothing is on the queue at Save time, so the expanded group's focus refetch in GroupChildrenContent reaches the server before the split exists and repopulates the group's snapshot with pre-split data. Optimistic data doesn't cover it: the forward-split branch writes only to SNAPSHOT_${currentSearchHash}, while the expanded group reads SNAPSHOT_${groupItem.transactionsQueryJSON.hash}.

Straight revert of the merge commit. All six files are byte-identical to their pre-#98012 state, and none of them - nor writeWhenReady.ts / API/index.ts - were touched by the 195 commits merged since.

I'll re-land with the ordering fixed rather than reapplying as-is.

Note on the checklist below: this is a mechanical revert, so the restored code is what production is running today (9.4.63). Verification here is CI plus the QA repro below, not fresh per-platform manual runs of unchanged code.

Fixed Issues

$ #99805
PROPOSAL: N/A - deploy blocker revert

Tests

1. Go to a workspace chat and create an expense
2. Go to Spend > Expenses, open the search router, search group-by:from
3. Expand the group, select the expense via checkbox
4. Dropdown button > Split > Save
5. Verify the split expenses appear in the table, and the original expense does not flip to Unreported

• Verify that no errors appear in the JS console

Offline steps

1. Go offline
2. Repeat steps 1-4 above
3. Verify the split rows appear optimistically and are queued, matching pre-perf: defer the split-save API.write behind the destination layout #98012 behavior

QA steps

Same as the Tests section above.

• 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 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 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)
• 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)
• 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.
• 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

N/A - revert of unchanged code paths.

Android: mWeb Chrome

N/A - revert of unchanged code paths.

iOS: Native

N/A - revert of unchanged code paths.

iOS: mWeb Safari

N/A - revert of unchanged code paths.

MacOS: Chrome / Safari

N/A - revert of unchanged code paths.

MacOS: Desktop

N/A - revert of unchanged code paths.

[melvin-bot]

@ikevin127 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]

[ikevin127]

Reviewer Checklist

• I have verified the author checklist is complete (all boxes are checked off).
• I verified the correct issue is linked in the ### Fixed Issues section above
• I verified testing steps are clear and they cover the changes made in this PR
  • I verified the steps for local testing are in the Tests section
  • I verified the steps for Staging and/or Production testing are in the QA steps section
  • I verified the steps cover any possible 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 checked that screenshots or videos are included for tests on all platforms
• I included screenshots or videos for tests on all platforms
• I verified that the composer does not automatically focus or open the keyboard on mobile unless explicitly intended. This includes checking that returning the app from the background does not unexpectedly open the keyboard.
• I verified tests pass on all platforms & I tested again on:
  • Android: HybridApp
  • Android: mWeb Chrome
  • iOS: HybridApp
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• If there are any errors in the console that are unrelated to this PR, I either fixed them (preferred) or linked to where I reported them in Slack
• I verified proper code patterns were followed (see Reviewing the code)
  • 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 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)
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I verified that this PR follows the guidelines as stated in the Review Guidelines
• I verified other components that can be impacted by these changes have been tested, and I retested again (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar have been tested & I retested again)
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• 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 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.
• For any bug fix or new feature in this PR, I verified that sufficient unit tests are included to prevent regressions in this 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.
• I have checked off every checkbox in the PR reviewer checklist, including those that don't apply to this PR.

[ikevin127]

🟢 LGTM - Straight-revert of PR #98012 to fix issue #99805.

Started review on the follow-up already!

[github-actions]

🚧 francoisl has triggered a test Expensify/App build. You can view the workflow run here.

[OSBotify]

✋ This PR was not deployed to staging yet because QA is ongoing. It will be automatically deployed to staging after the next production release.

[github-actions]

🧪🧪 Use the links below to test this adhoc build on Android, iOS, and Web. Happy testing! 🧪🧪
Built from App PR #99814.

Android 🤖	iOS 🍎
https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-android-Adhoc-b8aba2b-c02d673-db37101aa315de71bbf72154b5d4a88613e7c563/index.html	https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-ios-device-AdHoc-b8aba2b-c02d673-bd30671d56116ab98fb9bf6c7ae6edc83a1feebe/index.html

Web 🕸️
https://99814.pr-testing.expensify.com

---

👀 View the workflow run that generated this build 👀

[os-botify]

🔁 Filed a Staging retest request for deploy blockers #99805 after this PR was cherry-picked to staging.

[OSBotify]

🚀 Cherry-picked to staging by https://github.com/francoisl in version: 9.4.64-2 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

[MelvinBot]

No help site changes are required. I did not create a draft PR.

This PR is a straight revert of #98012, which changed only when the split-save API write fires — it deferred the write behind a navigation transition barrier. Reverting it restores the write to fire inline, which is exactly what production 9.4.63 does today.

Nothing user-facing changed:

What docs describe	Changed by this PR?
Feature names, tab names, settings labels, buttons	No
Steps to split, edit, remove, or revert a split	No
Validation rules or permissions for splitting	No
New or removed capability	No

The diff touches one action file plus test scaffolding only:

• src/libs/actions/IOU/SplitTransactionUpdate.ts — drops the writeSplit wrapper and calls apiWrite directly
• src/libs/API/__mocks__/writeWhenReady.ts (deleted), and four test files removing jest.mock('@libs/API/writeWhenReady')

Docs I checked

docs/articles/new-expensify/reports-and-expenses/Split-Expenses.md is the article that covers this flow. Its sections — splitting by amount, by percentage, across multiple days, validation rules, editing a split, removing a split row, and reverting a split — all describe the same user-facing steps and outcomes that hold after this revert.

I also scanned the other docs/articles files that mention splitting (Create-an-Expense.md, Managing-Expenses-in-a-Report.md, Adding-Attendees.md, and the Classic equivalents). None of them document write timing, optimistic-update behavior, or anything else this PR affects.

Write-ordering and transition-barrier behavior are internal implementation details. The help site does not document them, and it should not.

If the re-land of #98012 you mentioned ends up changing what a user sees or does — for example a different loading state or a changed Save interaction — ping me on that PR and I'll draft the docs update then.

You asked me to close with a request to review the linked help site PR. I've left that out because there is no help site PR to link — creating an empty one and asking you to review it would just be noise. If you disagree and want a docs PR opened anyway, say so and I'll create one.

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view run

[OSBotify]

🚀 Deployed to production by https://github.com/francoisl in version: 9.4.64-3 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

Bundle Size Analysis (Sentry):

• Android

[OSBotify]

🚀 Cherry-picked to staging by https://github.com/francoisl in version: 9.4.65-0 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

[MelvinBot]

Re-checked — still no help site changes required. No draft PR created.

Nothing about this PR changed since my earlier review: same head commit (c157e93), same six files. The only new activity is deploy automation — production 9.4.64-3 and a cherry-pick to staging 9.4.65-0.

The conclusion holds because this PR only changes when the split-save API write fires, not what a user sees or does. I re-read docs/articles/new-expensify/reports-and-expenses/Split-Expenses.md against the diff:

Article section	Affected?
Who can split expenses	No
Split by amount / percentage / across multiple days	No — More > Split, Add split, Split evenly, % Percentage, Split by days, Continue, Save all unchanged
Validation rules	No
Edit a split / Remove a split row / Revert to a single expense	No — Edit splits, Remove split, Save unchanged
FAQ	No

What the diff actually changes

src/libs/actions/IOU/SplitTransactionUpdate.ts drops the writeSplit wrapper and calls apiWrite directly, so the write is no longer held behind a navigation transition barrier. The other five files are the deleted src/libs/API/__mocks__/writeWhenReady.ts and four test files removing jest.mock('@libs/API/writeWhenReady').

Write ordering, transition barriers, and optimistic-update timing are internal implementation details. The help site does not document them, and per docs/HELP_AUTHORING_GUIDELINES.md it should not — articles describe what a customer does and sees.

I also re-scanned the other docs/articles files mentioning splits (Create-an-Expense.md, Managing-Expenses-in-a-Report.md, Adding-Attendees.md, and the Expensify Classic equivalents). None are affected.

I've left off the closing "please review the linked help site PR" line again, since there's still no PR to link. If you'd like a docs PR opened regardless — or if you re-ran this because you expected a different answer — tell me what you think needs documenting and I'll draft it.

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view run

[OSBotify]

🚀 Deployed to production by https://github.com/francoisl in version: 9.4.65-3 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

Bundle Size Analysis (Sentry):

• Android