The C1 credential-hygiene fix converted InitializeAsync and ReadAsync to
surface only ex.GetType().Name, but left HandlePollError building its
operator-facing Degrade() message from raw ex.Message, gated only by
'if (ex is DbException) return;'. That guard exists for the I1
double-classification concern, not for message safety, and it is incomplete
for the leak vector: a malformed connection string throws ArgumentException
from the keyword parser (the same unquoted-';'-in-password shape the sibling
SqlDriverBrowser.Sanitize special-cases), which is not a DbException and so
reaches Degrade(ex.Message) unredacted.
It is unreachable in today's control flow only because the connection string
is static and validated identically at Initialize first — an emergent
property, not an enforced invariant, and a live per-poll leak the moment a
future edit (refresh-on-reinit, a different provider) breaks that assumption.
Make the fallback type-only like the other two sites; the full exception still
reaches the log sink via the exception parameter. The I1 defer + control tests
are unaffected (they assert Degraded, not message text). Pinned by a new test
driving a credential-bearing ArgumentException through HandlePollError;
verified load-bearing (red against Degrade(ex.Message), green after).
Closes the C1 review finding on commit 37f444b9.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
C1: SqlDriver's Initialize/Read failure paths no longer interpolate the ADO.NET
provider's ex.Message into LastError, the thrown message, or host status — only
ex.GetType().Name reaches the operator surface; the full exception goes to the log
sink via the structured logger's exception parameter. The driver is dialect-agnostic
over an arbitrary DbProviderFactory, so it cannot rely on any provider's message
discipline (Microsoft.Data.SqlClient's parser echoes an unrecognised keyword
lower-cased, which a value-based redactor misses).
C1a: replace the vacuous credential test (SQLite's "unable to open" message never
contains the connection string, so it passed regardless) with one that fabricates a
DbException whose own .Message carries a credential token and drives it through the
Initialize liveness-failure path via the injectable factory seam — red against the
pre-fix ex.Message interpolation.
I1: HandlePollError now ignores the DbException class ReadAsync already classified,
so a subscribed-read outage is classified (and logged) once, not twice with the
worse message.
I2: the poll's Healthy verdict routes through a shared SetHealthUnlessFaulted guard
(the one Degrade already used), so a late in-flight poll cannot un-fault a driver a
concurrent ReinitializeAsync just faulted.
I3: DiscoverAsync warns when materializing an omitted-type tag as String, the only
operator signal for the declared-vs-published type mismatch on a numeric column.
M1: BuildTagTable wraps the per-entry parse so a stray non-JsonException throw skips
the tag instead of stranding health at Initializing (it runs before Initialize's
try/catch). M2 left as a documented TODO to avoid touching SqlPollReader.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
SqlDriver implements IDriver / ITagDiscovery / IReadable / ISubscribable /
IHostConnectivityProbe / IAsyncDisposable over the landed SqlPollReader,
mirroring ModbusDriver. IWritable is deliberately absent: v1 is read-only
structurally, and every discovered variable is SecurityClass=ViewOnly.
The shell classifies poll outcomes because nothing below it does. The reader
honours IReadable literally — it throws only when the database is unreachable
and Bad-codes everything else — so a frozen database returns all-BadTimeout
snapshots through a perfectly successful PollGroupEngine tick. Without
ObservePollOutcome the driver would report Healthy while every value was Bad.
Connection-class codes (BadTimeout / BadCommunicationError) degrade health and
report the host Stopped; authoring-class codes (unresolvable RawPath, absent
row, type mismatch) change nothing, so a tag typo never reports the database
down. It deliberately does NOT synthesise an exception to earn engine backoff:
the engine's exception path publishes nothing, which would cost clients the
Bad quality the reader went out of its way to produce.
Initialize builds the authored RawPath table first (pure, cannot fail; a
malformed TagConfig is logged and skipped) then verifies liveness over one
open-use-dispose connection bounded by wall clock as well as by token (the
R2-01 lesson) — failure records Faulted and rethrows so DriverInstanceActor
retries. The connection string is never logged: a credential-free
server/database Endpoint is the only rendering that reaches a log, LastError,
or the host status.
DriverTypeNames.Sql is NOT added here — DriverTypeNamesGuardTests asserts
bidirectional parity with registered factories, so the constant must land with
the factory (Task 11). SqlDriver.DriverTypeName carries the string until then.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty