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Fix jumps when new message appears while user scrolled up#88536

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mountiny merged 5 commits intoExpensify:mainfrom
callstack-internal:VickyStash/bugfix/88238-fix-new-message-indication
Apr 24, 2026
Merged

Fix jumps when new message appears while user scrolled up#88536
mountiny merged 5 commits intoExpensify:mainfrom
callstack-internal:VickyStash/bugfix/88238-fix-new-message-indication

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@VickyStash VickyStash commented Apr 22, 2026 •
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Explanation of Change

When a new report action arrives, and the user is scrolled up in the chat history, the inverted FlashList re-layout can shift the content under the user position, causing a visible jump. This happens because maintainVisibleContentPosition (MVCP) was only engaged during the deep-link handoff and then permanently disabled, leaving nothing to pin the visible anchor when items are prepended to the inverted list later.

This PR re-enables MVCP when the user is scrolled away from the bottom (offset > 250px, matching ACTION_VISIBLE_THRESHOLD), so newly arriving messages no longer push the current viewport around.

Fixed Issues

$ #88238
PROPOSAL: N/A

Tests

  • Verify that no errors appear in the JS console
  1. Open a chat conversation
  2. Scroll up slightly (so you are not at the bottom)
  3. Have another user send a message
  4. Observe the chat window
  5. When a new message is received, the chat should either:
  • Auto-scroll to the latest message, or
  • Show a clear “new message” indicator (e.g., banner or badge), without extra jumps
    Note: badge won't be visible if user is below or at banner position.

Additional WEB test:

  1. Open the app
  2. Create a workspace.
  3. Go to workspace chat.
  4. Create an expense.
  5. See the report is not scroll up after creating an expense.

Additional iOS test:

  1. Open the chat
  2. On a conversation, click on the + button in the compose box
  3. Click on add attachment
  4. Upload a PDF
  5. The chat should automatically scrolls to the latest message after sending a PDF file, and the PDF preview should be fully visible in the chat.

Offline tests

Same, as in Tests section

QA Steps

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

  • Verify that no errors appear in the JS console

Same, as in Tests section

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)
    • 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
android.mp4
Android: mWeb Chrome
android_web.mp4
iOS: Native
ios.mov
ios1.mov
iOS: mWeb Safari
ios_web.mov
MacOS: Chrome / Safari
web.mp4
web1.mp4

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codecov Bot commented Apr 22, 2026 •
edited by github-actions Bot
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Codecov Report

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

Files with missing lines Coverage Δ
...c/components/FlashList/InvertedFlashList/index.tsx 100.00% <100.00%> (ø)
src/components/FlashList/useFlashListScrollKey.ts 100.00% <100.00%> (ø)
src/pages/inbox/report/ReportActionsList.tsx 77.91% <100.00%> (+0.21%) ⬆️
... and 101 files with indirect coverage changes

@VickyStash VickyStash marked this pull request as ready for review April 22, 2026 15:12
@VickyStash VickyStash requested review from a team as code owners April 22, 2026 15:12
@melvin-bot melvin-bot Bot requested review from ShridharGoel and trjExpensify and removed request for a team and trjExpensify April 22, 2026 15:12
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melvin-bot Bot commented Apr 22, 2026

@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]

@melvin-bot melvin-bot Bot removed the request for review from a team April 22, 2026 15:12
@VickyStash VickyStash mentioned this pull request Apr 22, 2026
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@Julesssss Julesssss self-requested a review April 22, 2026 16:25
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ShridharGoel commented Apr 22, 2026 •
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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 there are no new alerts related to the canBeMissing param for useOnyx
  • I verified proper code patterns were followed (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
    • 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 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)
  • 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
  • If a new component is created I verified that:
    • A similar component doesn't exist in the codebase
    • All props are defined accurately and each prop has a /** comment above it */
    • The file is named correctly
    • 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
    • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
    • Any internal methods bound to this are necessary to be bound (i.e. avoid this.submit = this.submit.bind(this); if this.submit is never passed to a component event handler like onClick)
    • All JSX used for rendering exists in the render method
    • 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 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 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.
  • 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.

Screenshots/Videos

Android: HybridApp
Screen.Recording.2026-04-24.at.10.37.09.PM.mov
Android: mWeb Chrome
iOS: HybridApp
Screen.Recording.2026-04-24.at.10.40.48.PM.mov
iOS: mWeb Safari
Screen.Recording.2026-04-24.at.10.33.10.PM.mov
MacOS: Chrome / Safari
Screen.Recording.2026-04-24.at.10.30.00.PM.mov

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ShridharGoel commented Apr 22, 2026

@VickyStash I'm still able to repro the same issue (also notice that the new message pill is also not showing on the top)

Screen.Recording.2026-04-22.at.10.28.54.PM.mov

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VickyStash commented Apr 22, 2026

@VickyStash I'm still able to repro the same issue (also notice that the new message pill is also not showing on the top)

@ShridharGoel Can you please provide the steps for reproduction, so I can repro it on my end?
Is it jumps to the top for you?

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ShridharGoel commented Apr 22, 2026

  1. Login as A.
  2. Open a DM with another user (B).
  3. Login as B in another window.
  4. Open the chat in B in a new window.
  5. Scroll to the middle of the chat in A.
  6. Send a message from B to A.
  7. Observe.

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VickyStash commented Apr 22, 2026

@ShridharGoel I can't reproduce it on my end.
Can you please try to reinstall node_modules and let me know if you still see the weird behavior?
If so, can you please provide me steps/videos for the fresh account?

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sosek108 commented Apr 23, 2026

Hi, @VickyStash is on sick leave and I'll be replacing her. @ShridharGoel if you have any request, please tag me

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github-actions Bot commented Apr 23, 2026

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

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@melvin-bot melvin-bot Bot requested a review from mountiny April 24, 2026 17:11
@mountiny mountiny merged commit dabe385 into Expensify:main Apr 24, 2026
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github-actions Bot commented Apr 24, 2026

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

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github-actions Bot commented Apr 24, 2026

🧪🧪 Use the links below to test this adhoc build on Android, iOS, and Web. Happy testing! 🧪🧪
Built from App PR #88536.

Android 🤖 iOS 🍎
https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-android-Adhoc-dabe385-7639cf7-526e6a8ce2c4ffc75bde072f0e5b9d6c0af9bd97/index.html https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-ios-device-AdHoc-dabe385-7639cf7-d2b0acbb711634a0df9bbec91a77b0ccd204a81d/index.html
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👀 View the workflow run that generated this build 👀

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OSBotify commented Apr 24, 2026

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

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OSBotify commented Apr 27, 2026

🚀 Deployed to staging by https://github.com/mountiny in version: 9.3.62-5 🚀

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

Bundle Size Analysis (Sentry):

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MelvinBot commented Apr 27, 2026

No help site changes are required for this PR.

The changes are purely internal UI bug fixes to FlashList scroll behavior (InvertedFlashList, useFlashListScrollKey, ReportActionsList) that prevent chat content from jumping when new messages arrive while the user is scrolled up. No user-facing features, settings, labels, or workflows were added or changed.

@mitarachim mitarachim mentioned this pull request Apr 27, 2026
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mitarachim commented Apr 27, 2026

Deploy Blocker #88955 was identified to be related to this PR.

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OSBotify commented Apr 28, 2026

🚀 Deployed to staging by https://github.com/mountiny in version: 9.3.64-0 🚀

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

Bundle Size Analysis (Sentry):

@arosiclair arosiclair mentioned this pull request Apr 29, 2026
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@mountiny mountiny mountiny approved these changes

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@ShridharGoel ShridharGoel ShridharGoel approved these changes

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