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ClarituneClaritune/mutantx/.cursor/skills/mx-test/SKILL.md

mx-test

Skill2 starsChanged 4 months agoMITView on GitHub

MutantX Phase 3 — Test each mutant by applying patches, running the test suite, and recording results.

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    If the user runs /mx-test, execute the script using the Bash tool:

    line 64

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SKILL.md

MutantX — Phase 3: Mutant Testing

This phase is handled by the deterministic Python script mx-test.py. It applies each mutant patch, runs the test suite, records results, and reverts — all without consuming AI tokens.

How to Run

Locate mx-test.py from the MutantX installation. It is in the scripts/ directory alongside the skills:

python3 ~/.claude/scripts/mx-test.py

Or if MutantX is installed at a known path:

python3 /path/to/mutantx/src/scripts/mx-test.py

Options

FlagDescription
--mutants-dir PATHPath to the .mutants/ directory (default: .mutants)
--timeout NTest command timeout in seconds (default: 120)
--skip-baselineSkip the baseline test run
--no-clean-checkSkip the clean-tree check on the files to be mutated
--strict-cleanRequire the whole working tree to be clean, not just the mutated files
--retestRe-test all cached results without regenerating patches
--skip-final-checkSkip re-running the tests on unmutated code after the last mutant

What the Script Does

  1. Pre-flight checks:
    • Verifies the files to be mutated have no uncommitted changes (the whole tree with --strict-clean)
    • Runs baseline tests to confirm they pass on unmodified code
  2. For each pending mutant:
    • Applies the patch: git apply .mutants/patches/NNN.patch
    • Runs the build command (if build_command is set), then the test command, with a timeout
    • Records the result:
      • killed: tests ran and at least one failed
      • killed-crash: the test process crashed (signal exit such as SIGSEGV/SIGABRT, or a crash report in the output)
      • killed-build: the build step failed (only when build_command is set)
      • timeout: the run exceeded the timeout
      • survived: all tests passed
      • skipped: the patch was missing or failed to apply
    • All killed-* statuses and timeout count toward the mutation score
    • Reverts the patch: git apply -R .mutants/patches/NNN.patch, then restores each patched file from a byte-for-byte backup if it still differs, so local edits are never discarded
    • Saves progress to manifest.json after each mutant
  3. Final check: re-runs the tests on unmutated code and fails loudly if they no longer pass (a failed revert or a stale build)
  4. Supports resuming — only tests mutants with status: "pending". Cached results are reset to pending automatically when the test files or test command change.

When Invoked as a Skill

If the user runs /mx-test, execute the script using the Bash tool:

python3 <path-to-mx-test.py> --mutants-dir .mutants

Find mx-test.py by checking these locations in order:

  1. ./src/scripts/mx-test.py (if inside the MutantX repo)
  2. ~/.claude/scripts/mx-test.py (global install)

Display the script output to the user as it runs.

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