Proposal: MV3 browser-extension lifecycle stress harness

[pi0n00r]

Context

I would like to contribute a test harness for the recurring class of browser-extension lifecycle races represented by bitwarden/clients#13299 and the related field symptom described in this comment. I am not asserting that those reports share one root cause.

Proposed contribution

Add a test-only, Chromium MV3 lifecycle harness to the existing browser test infrastructure. It would:

• run against a synthetic vault and test account only, with no real credentials or production service dependency;
• explicitly terminate and recreate the extension service worker;
• exercise popup open/close timing, vault timeout, sync, offline/online transitions, and browser sleep/wake equivalents;
• record metadata-only account, crypto, sync, vault-emission, popup, and worker-generation transitions;
• assert that contradictory states such as "UI unlocked while decrypted vault data is unavailable" and unbounded loading cannot persist;
• use seeded event scheduling so failures can be replayed, then reduced into deterministic regression cases.

I would keep the initial PR narrow: establish the lifecycle driver, synthetic fixture, transition trace, invariant assertions, and deterministic seed replay. Randomized stress execution could remain opt-in or scheduled rather than burden every PR run.

Maintainer guidance requested

Before writing the PR, which current Bitwarden test layer should own this: the browser Jest suite, another existing browser E2E framework, or a new test target under apps/browser? Also, would maintainers prefer the seeded stress job to be opt-in, scheduled, or part of CI with a small fixed seed set?

If this shape is acceptable, I am willing to implement it and start with the smallest reviewable harness PR.

[github-actions[bot]]

✨ Thank you for your code contribution proposal! While the Bitwarden team reviews your submission, we encourage you to check out our contribution guidelines.

Please ensure that your code contribution includes a detailed description of what you would like to contribute, along with any relevant screenshots and links to existing feature requests. This information helps us gather feedback from the community and Bitwarden team members before you start writing code.

To keep discussions focused, posts that do not include a proposal for a code contribution will be removed.

• 💡 For feature requests and general discussion, please visit the Bitwarden Community Forums.
• ℹ️ For questions and support, visit the Bitwarden Help Center.
• 🐛 To report a potential bug, please visit the corresponding repo. Server | Clients | iOS | Android

Thank you for contributing to Bitwarden!