Let a host app sign the panel in and open a run

[DavertMik]

A desktop app that launches Chrome with this extension loaded can hand the panel a ready session, so the tester never pastes a token to run the test the app just sent them to. Built for Testeiya, but nothing here knows about Testeiya beyond the name it puts in the file.

The contract

The host drops handoff.json beside the manifest and opens the panel:

{
  "app": "Testeiya",
  "baseUrl": "https://app.testomat.io",
  "projectId": "my-project",
  "jwt": "eyJ…",
  "projectToken": "tstmt_…",
  "runUrl": "https://app.testomat.io/projects/my-project/runs/abcd1234",
  "at": 1756160000000
}

Two credentials because the panel talks to two APIs: projectToken is what /api/v2 takes, jwt is a web session for the routes v2 lacks. runUrl is optional. at is milliseconds and has to grow on every push.

A file rather than a command line: --load-extension argv is readable by every process on the machine, and these are credentials. A panel already open takes a new push through window.TestomatHandoff.apply(), which answers {ok, projectId, run} so the host can report the result; a build without that global predates this contract.

Beside a token the tester pasted

An offer overlays the ordinary sign-in, it never replaces it. Their General token and their preferences are kept, and each request uses whichever credential fits — the project token on the project it was issued for, their own token anywhere else, the handed session for the web API. So the project switcher stays open for a tester who has their own token and is pinned for one who does not, and when the host closes its browser the panel keeps working on their token instead of falling back to nothing.

jwt is never stored. It lives in memory exactly like the one POST /api/login returns, and is re-read from the file on every panel load — which is why the file stays until the host that wrote it deletes it. Disconnect can't delete a file it doesn't own, so it marks that at answered and a newer push wins.

Also here

openRunFromUrl now reports whether it actually landed the panel on a view. A run that 404s used to leave the panel showing nothing at all — reachable today through "Run in Extension", and reachable more often once a host is pushing runs.

Checked

Driven against a real project on a real instance: cold boot, a live poke switching runs in place, both API surfaces answering, decline-then-newer-push, a handoff landing on top of an existing token and the fallback after the file goes. With no host involved the panel logs one ERR_FILE_NOT_FOUND for handoff.json at boot — that is the check for the file, not a fault.

🤖 Generated with Claude Code

[DavertMik]

Superseded by #73, which carries these commits plus the auth change that grew out of them: authorizing at /app-auth hands back a session that can read each project's own v2 key, so the panel needs one credential and projectToken in the handoff drops to an optional shortcut. The contract described here changed with it, so closing this in favour of the one PR.