Whole-artifact review of e43cd34 returned one blocking finding: three
mutations required runtime state that none of their prescribed artifacts is
required to emit.
M1 wants the applied OperationEffect and minted members; M2 the still-empty
members and invariant-21 verdict; M5 the post-undo members plus the
invariant witness. But pin 7 says only that t8b inverts, and gate 13 and §6
item 2f prescribe source assertions plus a normal pass verdict -- a
passing-test evidence model. A mutated test stops at its first failed
assertion, so state carried anywhere else is never printed, and M5's witness
assertion may not execute at all.
Fixed by pinning observation harnesses:
- Pin 7a: t8b binds the OperationEffect, the resulting StaffGroup.members and
the invariant-21 verdict to locals BEFORE its first assertion, and formats
all three into EVERY assertion's failure message.
- Pin 5a: u5 binds the post-undo g.members and the check_invariants
violations with witness ids before assertion 2, and formats both into
assertions 2 and 3.
- Gates 13 and 14 quote those diagnostics from source. M1, M2 and M5 quote the
resulting failure output verbatim.
The finding is revision E's, one case over. Revision E chose "quote the source
assertion plus the pass verdict," which is correct for a PASSING test, since
that is all a passing test emits. Mutations need the failing case, and the
failing case has exactly one channel: the diagnostic of the assertion that
fired. Settling the first did not settle the second.
The ordering half would have survived a careless fix. Putting each observation
in "its own" assertion reads as tidy and is precisely wrong: M1 trips t8b's
spurious-order assertion and M2 the missing-order one, so a message carrying
only its own value disarms whichever mutation trips the other. In u5 it is
worse -- M5 trips assertion 2, making assertion 3's witness unreachable by
construction. The state a mutation owes must be bound before the assertion
that mutation trips.
Rather than pin this three times, §3 now heads with the general rule, which
also covers the mutations the review did not cite: where the observation is a
single value under assert_eq!, the default left/right diagnostic carries it,
and M3, M4 and M9 qualify provided they compare the verdict rather than
assert!(matches!(...)), which prints nothing -- the report must state which
form each uses. Where the observation is composite, or behind an assertion the
mutation makes unreachable, a harness is required.
Still DRAFT, still unratified. No implementation work has begun.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ps1szk2mSfgp4Cz21eVH9x
Levi Neuwirth
3e0a4d38c1