testfx-test-value-evidence

# TestFx test-value evidence Read and apply the canonical [test-value-evidence skill](../../../.agents/skills/test-value-evidence/SKILL.md) first, then these repository-specific requirements. Keep the canonical vendored file unmodified; its source revision and blob are recorded in [eng/vendored-files.json](../../../eng/vendored-files.json). - Read [repository instructions](../../copilot-instructions.md). Use the repository-pinned toolchain through `build.cmd` or `build.sh`, capture binary logs for MSBuild commands, and use the owning project's assertion conventions and `BannedSymbols.txt`. MSTest framework tests use `TestContainer`; MTP and analyzer tests use MSTest; adapter tests use their established assertion APIs. - Apply [parallel-safety preflight](../testfx-parallel-safety-preflight/SKILL.md) before test/lifecycle changes and against the final diff. Counterfactual experiments must use isolated outputs and preserve the actual test scheduling. - For acceptance, package, launcher, protocol, or cross-component changes, apply [acceptance validation](../testfx-acceptance-validation/SKILL.md). Repack each product variant before testing, prove the effective package/cache and loaded binary paths, and retain real shipping-layout evidence. Assert/API overload changes also need the repository's packed source-compatibility coverage. - Reuse the installed [test-gap-analysis](../../../.agents/skills/test-gap-analysis/SKILL.md) for bounded static reasoning and the existing [mutation workflow](../../workflows/mutation-testing.yml) for available executed Stryker evidence. Do not upgrade unrelated curated plugins to run this skill. - Keep publication under the [code-review gate](../code-review/SKILL.md). The automatic and `/review-tests` reviewers are read-only: report static predictions or unavailable proof unless exact matching execution records can be inspected. Do not execute PR code or infer red-green proof from green CI. Put material evidence gaps in the summary, not automatic inline findings. The existing review workflow reports the canonical evidence table for each eligible PR head, including unchanged tests protecting source-only changes. Individual commit validation is separate; neither the skill nor its vendored presence enforces a Git hook or proves live workflow publication.