fix(#20): heid-bug-hunt fixups — admin-stream + bifrost hardening (slice-6)

Cold spec-free panel (Gróa + Hulda + Regin, source-verified by Heid): the adapter's
core re-wrap is sound, but 4 real hardening gaps the conformance CR couldn't see —
all in failure-path normalization + open-world degrade, judged against the general
ConnectFailed floor + the degrade-never-crash promise. All fixed:

- [bug, 3/3] `stream_admin_events` never mapped `ConnectFailed` — the SDK admin-stream
  open raises it on a connect-time / auth-resolution failure (the general transport
  floor; confirmed in the SDK source), and `stream_turn` + the bifrost GET both catch
  it, and this endpoint's OWN comment claimed it did. An unmapped ConnectFailed escaped
  the web gen's `except (Sse*)` and aborted the SSE with no `stream_error`. Now mapped
  → `SseConnectFailed`, mirroring stream_turn.
- [bug, 2/3] non-str `type` crashed the web filter — the re-wrap used `ev.type or ""`
  (falsy-only), so a truthy non-str `type` (123, a list) reached `.startswith` →
  AttributeError. Now `ev.type if isinstance(ev.type, str) else ""` (matches the
  admin_id/data isinstance guards — same container-type class as slice-5).
- [robustness] `_session_bifrost_endpoint` did `dict(bstate)` on the open-world 200
  body — a non-mapping (list/scalar) → TypeError/500. Now degrades to `{}` (I introduced
  this in slice-6 by changing `JSONResponse(bstate)` → `dict(bstate)`).
- [robustness] `_admin_events_endpoint.gen` allocated the transport + built `_wt_client`
  BEFORE the try/finally — a construction failure would leak the httpx transport. Moved
  `_wt_client` inside the try so the finally always closes it.

Voided (Heid): Regin's `dict(ev.data)` TypeError — the `isinstance(_, Mapping)` guard
already routes non-mappings to `{}` before `dict()`.

Added adapter tests (ConnectFailed→SseConnectFailed; non-str type→"") + a web test
(non-mapping bifrost body → 200 {}). Suite 494 green; my code ruff-clean (13 E501/F841
in test_web_server.py are PRE-EXISTING, HEAD-identical, untouched); mypy clean on wt.py.
Live smoke re-run clean (real session.created event re-wrapped; bifrost 404 envelope).
Patch bump 0.21.19 → 0.21.20.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.21.19"
+version = "0.21.20"
 description = "Worldtree Conversation API debug console (web + headless CLI) — multi-pane observability"
 readme = "README.md"
 requires-python = ">=3.12"

src/ratatoskr/web/server.py

@@ -572,9 +572,10 @@ async def _session_bifrost_endpoint(request: Request) -> JSONResponse:
     """GET /api/sessions/{session_id}/bifrost → admin-scoped Bifrost dispatch state (#176).
 
     The admin key is SERVER-HELD (app.state.admin_key) and never reaches the
-    browser (INV-003 precedent — upstream credentials stay server-side); the
-    wrapper overrides the Authorization header with it. Fail-visible when the
-    admin key isn't configured (never a silent empty pane)."""
+    browser (INV-003 precedent — upstream credentials stay server-side); it rides on
+    the wt client's `admin_auth` (`_wt_client(admin_key=…)`), which the SDK uses for
+    the `admin.*` routes (NOT a per-call header — slice-6). Fail-visible when the admin
+    key isn't configured (never a silent empty pane)."""
     session_id = request.path_params["session_id"]
     admin_key = request.app.state.admin_key
     if not admin_key:  # PRE-001: fail-visible, never silent
@@ -598,7 +599,9 @@ async def _session_bifrost_endpoint(request: Request) -> JSONResponse:
             {"error_code": "network_error", "message": str(exc)},
             status_code=502,
         )
-    return JSONResponse(dict(bstate), status_code=200)
+    # Open-world read: degrade a non-mapping 200 body to {} rather than 500ing on
+    # `dict(non-mapping)` (heid bug-hunt slice-6).
+    return JSONResponse(dict(bstate) if isinstance(bstate, Mapping) else {}, status_code=200)
 
 
 def _admin_event_matches_web(ev: AdminEvent, session_id: str | None) -> bool:
@@ -627,11 +630,13 @@ async def _admin_events_endpoint(request: Request) -> Response:
 
     async def gen() -> AsyncIterator[bytes]:
         transport = client_factory()
-        # slice-6: admin_auth rides on the wt client (built with admin_key); the adapter
-        # re-wraps the SDK's AdminEvent → ratatoskr's (id/type/data degraded) and the
-        # stream's terminal SDK errors (incl. ConnectFailed) → the Sse* types below.
-        client = _wt_client(transport, admin_key=admin_key)
         try:
+            # slice-6: admin_auth rides on the wt client (built with admin_key); the
+            # adapter re-wraps the SDK's AdminEvent → ratatoskr's (id/type/data degraded)
+            # and the stream's terminal SDK errors (incl. ConnectFailed) → the Sse* types
+            # below. Built INSIDE the try so a construction failure still hits the finally
+            # that closes the transport — no leak (heid bug-hunt slice-6).
+            client = _wt_client(transport, admin_key=admin_key)
             async for ev in wt.stream_admin_events(client):
                 if not _admin_event_matches_web(ev, session_id):
                     continue

src/ratatoskr/wt.py

@@ -727,8 +727,9 @@ async def stream_admin_events(
     and `type`/`data` may be None (→ `""` / `{}`) — normalized HERE so the web filter +
     formatter (`ev.id` / `ev.type` / `ev.data`) never crash on a partial wire (chosen over
     yielding SDK events through + rewiring the web filter). Error map (INV-CUT-2, stream
-    rows): SDK `ApiError` (a non-200 open — the admin stream raises `admin_stream_failed`,
-    NOT `ConnectFailed`) → `SseConnectFailed`; SDK `ConnectionDropped` (a connect-time
+    rows): SDK `ConnectFailed` (a connect-time transport / auth-resolution failure — the
+    SDK's general transport floor) → `SseConnectFailed`; SDK `ApiError` (a non-200 open,
+    `admin_stream_failed`) → `SseConnectFailed`; SDK `ConnectionDropped` (a connect-time
     transport failure → cursor None, OR a mid-stream drop / the long-lived stream's
     resumable EOF → cursor) → `SseConnectionDropped`. The SDK stream is best-effort (skips
     malformed frames — no `Malformed*`).
@@ -737,14 +738,21 @@ async def stream_admin_events(
         async for ev in client.admin.stream_events(last_event_id=last_event_id):
             yield AdminEvent(
                 id=ev.admin_id if isinstance(ev.admin_id, int) else 0,
-                type=ev.type or "",
+                # isinstance-guard `type` (not `or ""`): a truthy NON-str type (123, a
+                # list from a partial wire) would otherwise reach `.startswith` in the
+                # web filter → AttributeError (heid bug-hunt slice-6; match admin_id/data).
+                type=ev.type if isinstance(ev.type, str) else "",
                 timestamp=ev.timestamp,
                 data=dict(ev.data) if isinstance(ev.data, Mapping) else {},
             )
     except wtsdk.ConnectionDropped as exc:
         raise SseConnectionDropped(last_seen_sse_id=exc.last_seen_sse_id) from exc
+    except wtsdk.ConnectFailed as exc:
+        # A connect-time transport / auth-resolution failure surfaces as ConnectFailed
+        # (the SDK's general transport floor) — map it → SseConnectFailed, mirroring
+        # stream_turn. The web gen catches the Sse* types, so an unmapped ConnectFailed
+        # would escape and abort the SSE with no labeled stream_error (heid bug-hunt).
+        raise SseConnectFailed(status=exc.status, body=(exc.message or "").encode()) from exc
     except ApiError as exc:
-        # The admin stream raises ApiError("admin_stream_failed", status=…) on a non-200
-        # open (a connect-time transport failure instead surfaces as ConnectionDropped);
-        # map the non-200 → SseConnectFailed so the web's stream-error handler catches it.
+        # A non-200 open raises ApiError("admin_stream_failed", status=…) → SseConnectFailed.
         raise SseConnectFailed(status=exc.status, body=(exc.body or "").encode()) from exc

tests/test_web_server.py

@@ -1276,6 +1276,19 @@ class TestSessionBifrostEndpoint:
         assert resp.status_code == 404
         assert resp.json()["error_code"] == "bifrost_state_unavailable"
 
+    @respx.mock
+    def test_non_mapping_body_degrades_to_empty(self) -> None:
+        """robustness: a non-mapping open-world 200 body (list/scalar) → 200 {} envelope,
+        never a `dict(non-mapping)` TypeError/500 (heid bug-hunt slice-6)."""
+        respx.get("https://w.example/admin/sessions/s-1/bifrost").mock(
+            return_value=httpx.Response(200, json=["not", "a", "mapping"])
+        )
+        from ratatoskr.web.server import create_app
+        app = create_app(_mock_client_factory(), admin_key="adm-key")
+        resp = TestClient(app).get("/api/sessions/s-1/bifrost")
+        assert resp.status_code == 200
+        assert resp.json() == {}
+
 
 class TestAdminEventsEndpoint:
     """admin_events_endpoint — SSE proxy of GET /admin/events, session-filtered (#11)."""

tests/test_wt.py

@@ -1205,17 +1205,41 @@ class TestStreamAdminEventsWt:
         assert fake.calls[-1] == ("stream_events", (), {"last_event_id": 42})
 
     async def test_non_200_apierror_maps_to_sse_connect_failed(self) -> None:
-        # The SDK admin stream raises ApiError("admin_stream_failed", status=…) on a
-        # non-200 open (NOT ConnectFailed) — mapped → SseConnectFailed for the web.
+        # A non-200 open raises ApiError("admin_stream_failed", status=…) → SseConnectFailed.
         fake = _FakeAdmin(stream_error=ApiError("admin_stream_failed", "no", status=502))
         with pytest.raises(SseConnectFailed) as ei:
             await _drain(stream_admin_events(_wtad(fake)))
         assert ei.value.status == 502
 
-    async def test_connection_dropped_maps_and_carries_cursor(self) -> None:
-        # Both a connect-time failure (cursor None) and a mid-stream drop / resumable
-        # EOF (cursor set) surface as ConnectionDropped → SseConnectionDropped.
+    async def test_connect_failed_maps_to_sse_connect_failed(self) -> None:
+        # A connect-time transport / auth-resolution failure surfaces as ConnectFailed
+        # (the SDK's general floor) → SseConnectFailed, mirroring stream_turn — else it
+        # escapes the web gen's Sse* handler and aborts the SSE (heid bug-hunt slice-6).
+        fake = _FakeAdmin(stream_error=wtsdk.ConnectFailed("connect_failed", "refused", status=0))
+        with pytest.raises(SseConnectFailed) as ei:
+            await _drain(stream_admin_events(_wtad(fake)))
+        assert ei.value.status == 0
+
+    async def test_nonstr_type_degrades_to_empty(self) -> None:
+        # A truthy NON-str `type` (a partial/wrong open-world wire) must degrade to ""
+        # so the web filter's `.startswith` never AttributeErrors — `or ""` (falsy-only)
+        # would let it through; the isinstance guard catches it (heid bug-hunt slice-6).
+        fake = _FakeAdmin(events=[_SdkAdminEvent(1, 123, "t", {"session_id": "s"})])
+        out = await _drain(stream_admin_events(_wtad(fake)))
+        assert out[0].type == ""
+
+    async def test_connection_dropped_carries_cursor(self) -> None:
+        # A mid-stream drop / resumable EOF carries the resume cursor.
         fake = _FakeAdmin(stream_error=wtsdk.ConnectionDropped("42"))
         with pytest.raises(SseConnectionDropped) as ei:
             await _drain(stream_admin_events(_wtad(fake)))
         assert ei.value.last_seen_sse_id == "42"
+
+    async def test_connection_dropped_none_cursor_connect_time(self) -> None:
+        # A connect-time transport failure surfaces as ConnectionDropped(None) →
+        # SseConnectionDropped(last_seen_sse_id=None) (the map's other cursor shape;
+        # heid-code-review slice-6 test-gap).
+        fake = _FakeAdmin(stream_error=wtsdk.ConnectionDropped(None))
+        with pytest.raises(SseConnectionDropped) as ei:
+            await _drain(stream_admin_events(_wtad(fake)))
+        assert ei.value.last_seen_sse_id is None

uv.lock

@@ -472,7 +472,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.21.19"
+version = "0.21.20"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },