Browser Downloads archiver and backup tool - 6th July 2025 - 12th July 2025 - Browser Downloads archiver and backup tool - PLDG 3 #151

pranavvdesai · 2025-07-14T12:44:27Z

pranavvdesai
Jul 14, 2025

End-to-end testing of the Chrome extension on Chrome 119 (stable) and Chromium 121 (canary)
Fixed minor UI glitches in the popup (race condition between UCAN login and upload trigger)
Recorded and edited a full demo video showing install → login → download → auto-backup flow

What went well
- All core flows (login, download listener, upload to Storacha Space) work reliably after multiple session restarts.
- The demo confirmed that CIDs returned by the w3up-client are immediately resolvable via public gateways.
Challenges faced
- Service worker lifecycle – Manifest V3 terminates the background worker aggressively; had to persist upload state in chrome.storage.session and resume on onStartup.
- CORS + fetch streaming – Browser rejected chunked uploads when auth headers were appended dynamically; resolved by pre-signing the request via UCAN and sending a single fetch with a ReadableStream.
- UCAN token refresh – Tokens expired during long idle periods; implemented silent refresh and queued uploads until new capabilities arrived.
- File-system sandboxing – On macOS, sandboxed Chrome prevented access to ~/Downloads symlinks; switched to using chrome.downloads.search + FileSystemAccess API.
The build still focuses on the “happy-path” upload; robustness checks (selective sync, hidden-file exclusion, single-space enforcement) remain open.

Add robustness checks
- Selective sync (file-type / size filters)
- Hidden-file exclusion
- Ensure only one Storacha Space is delegated
Possiblity of only making the extension work when user Downloads in a particular folder to ensure security of user