testing/cross_backend/sse_round_trip.ts

Cross-process SSE round-trip suite — the cross-process counterpart to the in-process testing/sse_round_trip.ts harness.

Where the in-process harness reads a Hono Response.body directly, this suite opens a real streaming fetch against a spawned backend's audit-log SSE endpoint via create_sse_transport, threading the fresh-per-test keeper's session cookie. It is the only coverage of the spawned binary's live SSE path — the standard cross-process bundle (describe_standard_cross_process_tests) omits SSE by design, so consumers call this alongside it (paralleling describe_cross_process_ws_tests).

Four cases, mirroring the in-process SSE self-test against fuz_app's standard audit-log stream:

1. connects — the stream opens and emits the : connected comment.
2. data frame (gated on rpc_path) — a minted secondary's sessions are revoked over the keeper's admin channel (admin_session_revoke_all), broadcasting a session_revoke_all audit event as one data: frame to the subscribed keeper without closing its stream (the event targets the secondary, not the subscriber). The secondary is minted *before* the stream opens so create_account's own audit events (invite / signup / login / token) don't land on it.
3. close-on-revoke, account-wide (gated on rpc_path) — the subscriber's *own* sessions are revoked (account_session_revoke_all), so the session_revoke_all event targets the keeper and the audit guard drops the live stream via the account-wide close_for_account path. Asserted via SseTransport.wait_for_close.
4. close-on-revoke, session-scoped (gated on rpc_path) — the subscriber's *own* single session is revoked (account_session_revoke), so the session_revoke event drops the stream via the session-hash-scoped close_for_session path (the distinct primitive cases 2–3 don't reach).

The close-on-revoke matrix is layered: cases 3–4 exercise the account-wide and session-scoped paths cross-process; the remaining union events (token_revoke_all / logout / password_change, all account-wide; and role_grant_revoke, role-matched) are covered by the spine's fuz_realtime SSE-registry unit tests and the in-process guard self-test, so a cross-process token_revoke_all-with-zero-tokens case (which may emit no audit row) stays out to keep the spawned-backend suite non-flaky.

Gated on capabilities.sse — backends without an end-to-end SSE stream skip (the cases still surface as .skip in the report). Cross-process only: create_sse_transport needs a real bound socket, so wire it from a *.cross.test.ts file, never an in-process setup.