Two guards enumerated the same RawBrowseCommitMapper.BuildTagConfig seam against
two hand-authored lists, which can only drift. The older one's list was also
misnamed: DriverDispatchMapParityTests.NonBrowsableDriverTypes really meant
"types that produce the generic key" — AbLegacy is genuinely non-browsable yet
correctly absent from it, because it has a typed branch.
Retire the older fact. RawBrowseCommitMapperParityTests.GenericKeyExemptions is
now the single hand-authored list for this seam: named for what it holds, one
written reason per entry, and checked against a DI-derived browsable set rather
than a second list. The one assertion the retired fact made that nothing here
covered — set EQUALITY, i.e. an exemption must still DESCRIBE the mapper — moves
across as Every_generic_key_exemption_still_commits_to_the_generic_key. Without
it, a driver that gained a typed branch would keep a silently inert exemption.
Item 2: OpcUaClientDriverBrowser and GalaxyDriverBrowser returned string
literals ("OpcUaClient", "GalaxyMxGateway") where Sql/Mqtt use DriverTypeNames.
The values matched, and nothing guarded that. Repoint both at the constants —
DriverTypeNames.Galaxy carries the identical value — and add
Every_registered_browser_is_keyed_by_a_declared_driver_type_name over the same
AddAdminUI() read-back. Compared ORDINALLY: BrowserSessionService indexes on the
exact persisted string, and case-only drift (TwinCat/TwinCAT) is what
DriverTypeNames exists to end. Browser projects are out of reach of
DriverTypeNamesGuardTests, which pins the driver FACTORIES' names.
Falsified, four ways, each red naming the offender and green on revert:
- #555 re-run: disabling the Sql branch reddens the two enumeration facts
("...no dedicated BuildTagConfig branch...: Sql"), the same catch the
retired fact made.
- giving Modbus a typed branch reddens ONLY the new stale-exemption fact,
proving it is not redundant with the four that were already there.
- SqlDriverBrowser.DriverType => "SQL" and Galaxy => "GalaxyMXGateway" each
redden the new browser-key guard by name — case-only typos, which an
OrdinalIgnoreCase compare would have waved through.
RawBrowseCommitMapper.BuildTagConfig's unknown-driver fallback claimed to be
guarded by RawBrowseCommitMapperParityTests, which did not exist anywhere under
tests/. The claim it made — "every BROWSABLE driver is handled above" — is the
exact claim that stopped being true when SqlDriverBrowser registered (deferment.md
G-6), so the comment was asserting the invariant instead of pinning it.
The guard now exists and enumerates DriverTypeNames.All:
- Browsability's bespoke arm is DERIVED from production, not hand-listed: the test
runs AddAdminUI() and reads back every registered IDriverBrowser's DriverType —
the same set BrowserSessionService.CanBrowse indexes. A driver that gains or
loses a bespoke browser moves the guard with it.
- The universal arm (DiscoveryDriverBrowser -> ITagDiscovery) is NOT derivable from
the AdminUI assembly: it references driver Contracts/Browser projects, never the
runtime drivers, and IDriverFactory is composed in the Host. Covered instead by
requiring every declared driver type to be typed or explicitly exempted with a
reason (Modbus, Calculation), with a third fact mechanically refuting any
exemption the derived arm contradicts — the Sql failure mode.
Falsified three ways, each red naming the offender: disabling the Sql branch trips
the derived-arm fact; disabling the MTConnect branch trips the enumeration fact
(the universal-arm half, which no bespoke registration would have caught); adding
Sql to the exemption list trips the contradiction fact.
Comment corrected to state what the test actually asserts, including the residual
trust the universal arm leaves.
Joseph Doherty