TryFormatValue's catch filter named only FormatException / InvalidCastException
/ OverflowException, and the call sits OUTSIDE WriteAsync's per-slot try. But
Convert.ToString falls back to the value's OWN ToString/IFormattable - arbitrary
caller code that may throw anything - so any other exception escaped WriteAsync
uncaught and failed the entire batch, breaking the documented never-throws
per-slot contract. Broadened to a catch-all; the slot gets BadTypeMismatch and
the exception is logged at Warning (TryFormatValue became an instance method to
reach _logger). One unformattable value now costs its own slot and nothing more.
Falsification checked, not assumed: restoring the narrow filter makes the new
test fail with a raw "System.InvalidOperationException : this formatter is
broken" propagating out of WriteAsync - i.e. it fails for the contract-breach
reason, not on an assertion.
Two tests added:
- a value whose ToString throws InvalidOperationException is refused
BadTypeMismatch while the *following* good slot still writes (the load-bearing
half - it proves the batch survived).
- mid-batch cancellation: cancellation injected from inside slot 1's own
formatting, so slot 0 has provably already reached the Agent. It keeps its
real Good outcome while slots 1-2 fill BadCommunicationError. Reporting a
landed write as failed is worse than reporting a failure, and a fill that
started at 0 instead of i would do exactly that.
Tests: 534 passed / 0 failed (was 532). Solution build: 0 errors, no warnings
in any MTConnect project.
Joseph Doherty
b833dda673