OAuth authorization-server metadata lives at the origin root (RFC 8414), but
getRequiredConfig() derived the discovery URL straight from JMAP_SERVER_URL. When
that is the session URL (for example https://mail.example.com/jmap/session, a
common setup so the client can skip the 307 redirect a preflighted CORS request
cannot follow), discoverOAuth fetched
https://mail.example.com/jmap/session/.well-known/oauth-authorization-server,
got a 404, and token refresh failed with "OAuth token endpoint not found", so the
session was dropped after one access-token lifetime.
Strip a trailing session path (/jmap/session or /.well-known/jmap, plus any query
or fragment) before discovery. A plain server root is unchanged, and only the
session suffix is removed, so a real base path prefix is kept.
Adds oauth-discovery-base.test.ts driving getRequiredConfig; the normalization
cases fail without the fix.
Justin Willhite
b26c174628