Extends the off-loop suite to the third and last blocking method on the
`UpstreamAdapter` contract, the 401/429 rotation.
As with the two existing pairs, the primary assertion is **thread identity**,
not latency: a latency assertion measured by an HTTP client on the blocked
loop is vacuous, because the client's own timer cannot advance until the
block ends and it therefore reports a fast response on provably frozen code.
* `test_get_retry_credential_runs_off_the_event_loop` records
`threading.get_ident()` inside the fake adapter and compares it to the
loop thread, and checks the rotation still works end to end (rejected
bearer forwarded first, rotated bearer second).
* `test_event_loop_keeps_running_while_the_retry_credential_resolves`
samples a loop-side heartbeat counter from inside the stalled adapter. On
the unfixed handler it records exactly 0 loop iterations across a 0.5s
rotation.
* `test_retry_credential_failure_still_returns_the_upstream_rejection`
guards the error contract the change must leave alone: a raising rotation
is still swallowed and the upstream's own 401 is streamed back, with no
second forward.
A new `_build_rejecting_upstream` harness drives the `status in {401, 429}`
branch by rejecting every bearer except the rotated one.
Extends `test_proxy_off_loop.py` with the `/health` half, using the same
two-assertion shape as the credential tests:
- `test_is_authenticated_runs_off_the_event_loop` compares the thread the
adapter's `is_authenticated` ran on against the loop thread. Before the
fix they are the same ident.
- `test_event_loop_keeps_running_while_health_resolves_auth_state` reads a
loop-side heartbeat counter sampled by the adapter across its own stall.
Before the fix exactly 0 iterations run across 0.5s.
Both also assert the response is unchanged (`200`, `authenticated: true`),
so the offload cannot quietly alter what `/health` reports.
Adds `tests/hermes_cli/test_proxy_off_loop.py`, mirroring the harness in
`test_proxy.py`: the proxy and a fake upstream run as real aiohttp
servers on ephemeral ports under a single `asyncio.run`, guarded by
`pytest.importorskip("aiohttp")` — no pytest-aiohttp dependency.
The primary assertion is thread identity, not latency. A latency
assertion measured with an HTTP client on the blocked loop is vacuous:
the client's own timer cannot advance until the block ends, so it reports
a fast response on code that was provably frozen.
- `test_get_credential_runs_off_the_event_loop` records
`threading.get_ident()` inside the adapter and compares it to the loop
thread. Before the fix both are the same ident.
- `test_event_loop_keeps_running_while_credentials_resolve` runs a
heartbeat task on the loop and has the adapter sample its counter on
entry and exit, so the reading is taken from the loop rather than
through a client that shares it. Before the fix exactly 0 iterations
run across a 0.5s stall; after it, ~50.
- `test_credential_failure_still_maps_to_401` pins the error contract
across the change of call form. It is deliberately not in the
red-before set — it guards behaviour the fix must leave alone.
briandevans