[Uzaifm127]

Explanation of Change

In Expensify App on iOS native, the suggestion popup moves downward and can eventually disappear off-screen as more text is added after the composer reaches its maximum height.

The input scrolls internally, but MarkdownBackedTextInputDelegate replaces React Native's original text-input delegate without forwarding scrollViewDidScroll. This prevents React Native from delivering the updated scroll offset through onScroll. App then positions suggestions without accounting for the text that has scrolled out of view.

This change forwards scrollViewDidScroll to the original delegate when it supports the callback. App can then use the actual scroll offset to position suggestions above the visible caret. No text-layout or popup-positioning calculations are changed.

Fixed Issues

$ #105753
PROPOSAL:

Tests

1. Open the app.
2. Open any chat and focus the composer.
3. Type :smil on the first line.
4. Verify that the suggestion popup appears above the visible caret.
5. Delete :smil and type enough text to reach approximately six wrapped lines, or until the composer stops growing.
6. Type :smil at the end after leaving a space.
7. Verify that the suggestion popup appears above the visible caret
8. Delete :smil, add more text to reach approximately eight to ten wrapped lines, and type :smil again. Verify that the popup does not drift downward as the text scrolls internally.
9. Repeat with twenty to thirty wrapped lines.
10. Verify that the popup remains visible and correctly positioned.

• Verify that no errors appear in the JS console

Offline tests

Same as Test

QA Steps

Same as Test

• 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 verified any copy / text that was added to the app 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 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 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 the PR adds or modifies the UI:
  • I asked an AI agent to review the changes for accessibility issues and addressed its findings.
  • I tested with a screen reader (VoiceOver on macOS) and verified all new/changed elements are reachable with a logical focus order.
  • I verified all new/changed elements have meaningful accessible names and roles.
  • I verified state changes are announced (e.g. checked/unchecked, expanded/collapsed, selected).
• 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: mWeb Chrome

iOS: Native

iOS-scroll-offset-forwarding-fix.mov

iOS: mWeb Safari

MacOS: Chrome / Safari