The first Stryker pass (72.18%, up from 66%) showed the named dozen mostly
dead but surfaced two related gaps the "differs" style of assertion cannot
reach on its own:
- ComputeDigest's field-number and cites.role presence flags each had an
equality-mutation survivor (field.Number != null / selection.Cites.Role
!= null) that a same-vs-different digest comparison cannot catch: the
mutant swaps which of two cases gets which flag value, so both cases
still digest differently, just under swapped labels. A handful of plain
AppendString/sb.Append deletions survived alongside it for the same
reason - removing content that a same-vs-different pair didn't happen
to isolate. One independently reconstructed golden HMAC value, built
from the method's own doc comments rather than its private helpers,
pins the whole wire shape at once: any single append or flag polarity
wrong breaks the exact match.
- EdgesFor's OrderBy(pageRowIndex) - the primary "page-row order" key R-B
names before "(from, role, to)" - had no test forcing page position and
from/role/to order to disagree, so it survived alongside (and separate
from) the five ThenBy mutants already named.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>