A --since:29e50ad Stryker pass found real gaps, all inside this cut's own
files:
- vertex-placement and normals fixtures anchored a vertex at the world
origin, so a mutated (+ instead of -) or dropped cellSize multiply was
invisible against a zero operand; moved them off the origin;
- the cube normals test only checked length, and three orthogonal
+-2-length face contributions summed to the same length no matter which
one a mutant negated; now checks the exact expected direction per vertex;
- the open-boundary rule only had an X-axis test, leaving TryGetQuadCells's
Y- and Z-axis guards (and TryGetOtherEndpoint's Y/Z cases) uncovered;
added the Y- and Z-axis twins of the existing plane test;
- the 1e-20 near-zero-delta fallback in Interpolate was never exercised;
added a fixture with an edge delta of ~3e-21;
- CultGeometryGridEdge's Equals and ToString had no direct test.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Two spots failed to build: a method-group reference to float.IsFinite and an
`is 1 or 2` pattern inside a lambda that FluentAssertions compiles as an
Expression<Func<T, bool>>; expression trees can't contain pattern-matching
`is`, and a method group isn't implicitly convertible to an expression tree
either. Rewritten as explicit lambdas with `==`/`||`.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Adds SurfaceNetsTests.cs and QuadNormalsTests.cs covering the sign
convention, edge naming, outward winding, vertex placement (midpoint and
unequal-crossing means, origin/cellSize), closed-sphere welding and
Euler characteristic, an ambiguous checkerboard cell's even-but-not-2 edge
usage, open-boundary quad suppression, determinism/ordering, and
face-weighted normals (sliver-vs-large-quad area weighting, unit cube
normals, zero-area/untouched-vertex degenerate case). Adds
stryker-config.json (vstest runner; this project is NUnit 4, not xunit.v3)
and records GameCult.Geometry as scoped, diff-only, in
docs/mutation-testing.md's follow-ups.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
