perf: fix O(n²) tag scan in WorkspaceTagsPage

[TMisiukiewicz]

Explanation of Change

isDisablingOrDeletingLastEnabledTag(policyTagLists.at(0), [tag]) was called for every tag's showLockIcon prop inside the tagList map. Internally it calls getCountOfEnabledTagsOfList, which iterates all tags — O(n) per tag = O(n²) total. With 16k tags this amounts to ~256M filter iterations per render.

Fix: compute enabledTagsCount once before the map, then derive two O(1) boolean constants — isLastEnabledTagLocked and isLastEnabledTagAndEnabled — and use them inline. Behavior is identical: same lock icon logic, same modal guard.

Fixed Issues

$ #94044
$ #93952
PROPOSAL:

Tests

1. Go to workspace
2. Enable "Tags"
3. Add multiple tags
4. Navigate to workspace overview
5. Navigate to Tags
6. Verify Tags opens without any delay

• Verify that no errors appear in the JS console

Offline tests

N/A

QA Steps

Same as tests

• Verify that no errors appear in the JS console

PR Author Checklist

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Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

Screen.Recording.2026-06-19.at.14.19.07.mov

[codecov]

Codecov Report

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

Files with missing lines	Coverage Δ
src/pages/workspace/tags/WorkspaceTagsPage.tsx	46.87% <66.66%> (+0.55%)	⬆️
... and 14 files with indirect coverage changes

[melvin-bot]

@neil-marcellini 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]

[ZhenjaHorbach]

Created files with a lot of tags
If anyone needs it, you can use it 😁

workspace-tags-16k.csv
workspace-tags-32k.csv
workspace-tags-48k.csv
workspace-tags-multilevel.csv

[ZhenjaHorbach]

It looks like the web app is frozen after trying to open 16000 child tags for multi-tag 🥲
But technically, this PR should not fix this case

2026-06-19.15.02.03.mov

[ZhenjaHorbach]

Reviewer Checklist

• I have verified the author checklist is complete (all boxes are checked off).
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  • 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)
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  • 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)
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• 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.
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Screenshots/Videos

Android: HybridApp

2026-06-19.15.16.36.mov

Android: mWeb Chrome

2026-06-19.15.16.36.mov

iOS: HybridApp

2026-06-19.15.14.33.mov

iOS: mWeb Safari

2026-06-19.15.10.57.mov

MacOS: Chrome / Safari

Uploading Запись экрана — 2026-06-19 в 15.05.37.mov…

[TMisiukiewicz]

Yeah looks like it's a separate thing, we can open a separate issue for this one

[ZhenjaHorbach]

Okay then
Main workspace tags page works well!
LGTM

[mountiny]

I will create a follow up for that

[github-actions]

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

[github-actions]

🧪🧪 Use the links below to test this adhoc build on Android, iOS, and Web. Happy testing! 🧪🧪
Built from App PR #94041.

Android 🤖	iOS 🍎
https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-android-Adhoc-b2b2c11bb6d-912d4a2-827eb595a8b0c4d019ce3c627c45f2a8b67ff252/index.html	https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-ios-device-AdHoc-b2b2c11-912d4a2-3c48ff41d76822c5ad4cf17826e66136f0777d29/index.html

Web 🕸️
https://94041.pr-testing.expensify.com

---

👀 View the workflow run that generated this build 👀

[mountiny]

Tracking the multi-level child tag freeze separately in #94054 — out of scope for this PR.

[OSBotify]

🚀 Deployed to staging by https://github.com/mountiny in version: 9.4.16-1 🚀

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

Bundle Size Analysis (Sentry):

• Android
• iOS

[MelvinBot]

🤖 No help site changes required.

This PR is a pure performance optimization in src/pages/workspace/tags/WorkspaceTagsPage.tsx — it replaces a per-tag O(n²) scan (isDisablingOrDeletingLastEnabledTag called inside the tags map) with a single O(1) precomputed enabledTagsCount check.

The user-facing behavior is unchanged:

• Same lock icon logic on each tag's enable/disable toggle.
• Same "cannot delete or disable all tags" confirmation modal guard.
• No new features, settings, labels, tabs, or UI copy.

Since nothing changed about what the product does — only how fast the Tags page renders — no articles under App/docs/articles need updating, and no draft docs PR was created.

[OSBotify]

🚀 Deployed to production by https://github.com/blimpich in version: 9.4.16-5 🚀

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