83207: debounce autocomplete query and memoize search options

[abbasifaizan70]

Explanation of Change

The SearchRouter was passing autocompleteQueryValue (updated via useState on every keystroke) directly to SearchAutocompleteList, triggering synchronous getSearchOptions() + combineOrderingOfReportsAndPersonalDetails() + isSearchStringMatch() on every character typed, freezing the JS thread on mobile.

Structural optimizations (debouncing + memoization prevent redundant work):

• useDebouncedState for autocompleteQueryValue: Replaces useState so the expensive SearchAutocompleteList filtering only runs after the user pauses typing, not on every keystroke. The immediate value still drives arrow-key navigation and contextual logic.
• useMemo for searchOptions: Wraps getSearchOptions() so it only re-runs when its 13 dependencies actually change, instead of re-computing on every render.
• useMemo for recentReportsOptions: Wraps combineOrderingOfReportsAndPersonalDetails() so sorting/filtering is skipped when autocompleteQueryValue and searchOptions haven't changed.

Algorithmic improvement:

• isSearchStringMatch: new RegExp() per word per item → compile once per call, reuse across all items
• isSearchStringMatch: matching flag with continue past failures → early return false on first mismatch
• searchWords: new Set() keeping empty strings → Array.from(new Set(...)).filter(Boolean)

Performance (Reassure, 40K reports):

Metric	main (baseline)	PR (current)	Change
getFilteredOptions with search	2.8 ms	2.5 ms	-0.3 ms (-11.7%)
filterAndOrderOptions (40K items, 3-word query)	11.1 ms	10.4 ms	-0.7 ms (-6.4%)

Fixed Issues

$ #83207
PROPOSAL: #83207 (comment)

Tests

1. Open the app on a mobile device (iOS or Android) and tap the search icon in Inbox
2. Type rapidly into the search input (e.g. "Email Report Five") — verify the input stays responsive with no visible lag or dropped characters
3. Stop typing and wait briefly — verify search results update and reflect the typed query
4. Clear the search input — verify recent chats reappear immediately
5. Type a partial query (e.g. "Exp") — verify autocomplete suggestions appear after a short delay
6. Select an autocomplete suggestion — verify the query updates correctly and results reflect the selection
7. Use arrow keys (desktop) or scroll (mobile) to navigate through the results list while typing — verify navigation remains responsive
8. Type a multi-word query (e.g. "John Expense Report") — verify all matching results are returned correctly
9. Open search on a device/account with many reports and contacts — verify no JS thread freeze or unresponsiveness during typing
10. Press the back button or swipe to dismiss search while typing — verify navigation is not blocked

• Verify that no errors appear in the JS console

Offline tests

Same as tests.

QA Steps

Same as tests.

• 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
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  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
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  • MacOS: Chrome / Safari
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Screenshots/Videos

Android: Native

Screen.Recording.2026-04-02.at.4.04.17.AM.mov

Android: mWeb Chrome

Screen.Recording.2026-04-02.at.4.05.33.AM.mov

iOS: Native

Screen.Recording.2026-04-02.at.3.57.50.AM.mov

iOS: mWeb Safari

Screen.Recording.2026-04-02.at.3.58.48.AM.mov

MacOS: Chrome / Safari

Screen.Recording.2026-04-02.at.3.56.08.AM.mov

[codecov]

Codecov Report

❌ Looks like you've decreased code coverage for some files. Please write tests to increase, or at least maintain, the existing level of code coverage. See our documentation here for how to interpret this table.

Files with missing lines	Coverage Δ
...rc/components/Search/SearchRouter/SearchRouter.tsx	40.32% <50.00%> (-0.67%)	⬇️
src/libs/OptionsListUtils/index.ts	83.18% <0.00%> (+0.12%)	⬆️
... and 12 files with indirect coverage changes

[melvin-bot]

@aimane-chnaif 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]

[chatgpt-codex-connector]

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[trjExpensify]

PR doesn’t need product input as a performance PR. Unassigning and unsubscribing myself.

[aimane-chnaif]

Please merge main

[abbasifaizan70]

@aimane-chnaif Update with the latest main. Thanks

[MelvinBot]

🤖 Code Review

Overall this is a solid performance improvement — the debounce strategy and regex pre-compilation are both sound. A few items to consider:

---

1. Stale query fallback on line 350 (nit)

autocompleteQueryValue={textInputValue ? debouncedAutocompleteQueryValue || textInputValue : ''}

The || textInputValue fallback only fires when debouncedAutocompleteQueryValue is falsy (i.e. empty string). During normal typing it's always truthy (holding the previous query), so the fallback never kicks in mid-session — it only helps on the very first keystroke from empty. This is fine functionally (it's debouncing as intended), but the || textInputValue reads like it provides an immediate value during the debounce window, which it doesn't. A comment clarifying this would help future readers.

2. new RegExp(/ /g) on line 511 of OptionsListUtils/index.ts (nit, pre-existing)

const valueToSearch = searchText?.replaceAll(new RegExp(/ /g), '');

Wrapping a regex literal in new RegExp() is redundant — / /g alone works. This is pre-existing code though, so not something this PR needs to fix.

3. Perf tests look good — the filterAndOrderOptions test with 40K items and multi-word query is a great way to validate the regex optimization, and the SearchRouter render-count test covers the debounce path well.

No blocking issues — the changes are correct and well-scoped. 👍

[aimane-chnaif]

Can you please explain changes in this function?
What's this refactor for? Does this improve performance?
And add unit tests

[abbasifaizan70]

@aimane-chnaif This change is mainly a perf cleanup in a hot path, not intended to change behavior. Before, isSearchStringMatch() was creating a new RegExp inside the loop for every search word. Since this function runs across lots of options while typing, that adds unnecessary work on each keystroke.

What I changed:

• normalize/dedupe the words once
• compile the regexes once per function call
• reuse them in the loop
• return early on first mismatch

So matching logic stays the same, but we avoid repeated regex allocations and reduce JS work during search filtering.

[aimane-chnaif]

ok, please add unit test (not perf-test) for this function

[abbasifaizan70]

@aimane-chnaif Added unit test in OptionsListUtilsTest.tsx covering the refactored isSearchStringMatch path (multi-word normalization behavior), and it passes.

[chatgpt-codex-connector]

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Reviewed commit: e1d2ccc2af

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[abbasifaizan70]

@aimane-chnaif I added Unit test cases.

[MelvinBot]

🤖 Code Review

All CI checks pass. The debounce strategy and regex pre-compilation are correct. Two items worth addressing:

1. Unused debounce timer on textInputValue (line 79)

const [textInputValue, , setTextInputValue] = useDebouncedState('', 500);

The second element (debounced value) is never read — only the immediate value is used. This creates a 500ms debounce timer + state that serves no purpose. Consider using plain useState here instead, or destructure the debounced value if it's needed elsewhere.

2. First-keystroke empty flash (line 350)

autocompleteQueryValue={textInputValue === '' ? '' : debouncedAutocompleteQueryValue}

When the user types the first character, textInputValue becomes non-empty immediately but debouncedAutocompleteQueryValue is still '' (initial value, 300ms hasn't elapsed). The autocomplete list receives '' for 300ms on every typing burst. This is the intended debounce behavior, but please confirm DeferredAutocompleteList handles receiving '' while textInputValue is non-empty gracefully (e.g., shows recent searches rather than flashing empty content).

The isSearchStringMatch refactor is functionally equivalent — .filter(Boolean) correctly strips empty strings, return false early-exit matches the old matching flag semantics, and regex compilation is correctly hoisted out of the per-item loop. Unit test for multi-word normalization looks good.

No blocking issues.

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[abbasifaizan70]

@aimane-chnaif PR is ready for review. Thanks.