[orieg]

Closes #915.

What

The #911 merge rule (unreleased) read nested tests merged into a test named for their container as a merge in these conditions:

• the container kept the tests' assertion counts;
• it kept their literal expected values.

A merge that changed a non-literal operand (toBe(one) to toBe(two)) was therefore not reported, though 0.27.0 reported it as a removal.

merged_into_container now also requires the container to hold every equality operand of the tests it took over. Operands are compared as a multiset of digests (TestFn::equality_operands, both the different-operand and the self-comparison lists).

Docs:

• docs/GATES.md states the new condition and drops the known-miss line.
• The unreleased deletion-rationale: tests merged into one with every assertion kept are reported as removed #911 ledger row in docs/ROADMAP.md is updated in place.

No finding kind, configuration key or directive is added.

Evidence (RUN)

• Real PRs:

  • vitejs/vite#23604's real test file still reads as a merge (0 findings).
  • The deletion-rationale: a merge into the container test that changes a non-literal operand is not reported #915 repro is reported: 0.27.0 reported it, and the deletion-rationale: tests merged into one with every assertion kept are reported as removed #911 rule alone did not.

• Evasion corpus: js-merged-test-operand-changed is now caught as deletion-rationale/test-removed-without-rationale, and tests/test_evasion_corpus.rs passes.

• End-to-end: the new a_merge_that_compares_another_operand_is_a_removal test runs a merge with no literals. One that keeps both operands passes, as the negative control. One that compares l(one) with two reports build > b.

• Self-test: a new case, so 368 cases run, 0 failed.

• Mutation: with the operand check off, the new e2e test and the corpus case both fail, then pass once it is restored.

  A first e2e control (toBe(1) to toBe(one)) did not kill the mutant, because the expected-value check already catches a lost literal. It was replaced by the literal-free test above.

• Checks:

  • cargo fmt --check and cargo clippy --all-targets -- -D warnings are clean.
  • discipline docs --check and tests/action/check-links.py pass.
  • The full cargo test runs alongside CI.

Not run

No consumer replay was run. It runs at the 0.28.0 bump.