[HIGH] Investigate Search for reports hanging as user types

[mountiny]

Shared in Slack quality room

When typing to search for the reports, the ui can hang. Collected logs and profile traces shared in slack post to investigate

Issue Owner

Current Issue Owner: @sosek108

[melvin-bot]

Triggered auto assignment to @mallenexpensify (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[mallenexpensify]

Hey.. opened the bug from the thread and it's assigned to me!
Starting HIGH cuz Vit said he's seen it before and I suspect others have encountered too. Looks like Vit was on iOS

• HIGH -  UX Reliability, API Reliability and Performance issues that are part of main flows and affect a subset of users

[sosek108]

No significant update for now.

I saw no such error on Android emulator so I left this one for now and focused on iOS on which there are significant problems with Search input.
I see that each typed letter causes rerender of whole SearchRouter which is slighly significant and heavy rerener of AutocompleteList

Issues that may be connected:

• [AWAITING RETEST] [$250] iOS Hybrid - Search - app not apply the second character when typing offline #59262
• [Due for payment 2025-04-28] [Due for payment 2025-04-25] Search-Search syntax is not added to the field after clicking to search in the current chat #60395 (this is regression of [AWAITING RETEST] [$250] iOS Hybrid - Search - app not apply the second character when typing offline #59262)
• [Performance][MEDIUM] General performance investigation for opening app from customer profile trace #46595 (comment) (relates to FastSearch)

[sosek108]

No big update.

I've confirmed already what is said in other tasks. There are couple of places that could be improved and I see no "one quick fix" that will resolve that, but I'm trying - I'm doing POC of some refactror in SearchAutocompleteList to check this components bottlenecks.

• SearchInput is Markdown which alongside with parser gives unpleasent lag. Parser is generated by peggy so I am not sure if it could be impreoved
• After almost every keystroke FastSearch is created from scratch
• API call is send very often. I've got 2 API calls during quick 4 keystrokes. And each API response causes rerender of Search components
• SearchAutocompleteList render cost is very high (even when FastSearch is disabled)

Next:

• I am checking SearchAutocompleteList for improvement possibilities
• I will try to debounce keystrokes in Search Input (this was tried in [AWAITING RETEST] [$250] iOS Hybrid - Search - app not apply the second character when typing offline #59262 but maybe I'll have more luck)
• I will try to reduce cost of FastSearch generation. Instead of creation from scratch tree could be updated.
• I will check for possibilities to improve of SearchInput's parser

[mountiny]

Thanks for the updated, could we introduce more caching or debounce the search calls a bit more?