Mutation Testing — Campaign Configuration (mewt/muton)

Helps configure mewt or muton mutation testing campaigns — scoping targets, tuning timeouts, and optimizing long-running runs so you can execute mewt run or muton run with confidence.

Note: muton and mewt share identical interfaces but target different languages — mewt for general-purpose languages, muton for TON smart contracts (Tact, Tolk, FunC). All commands and configuration patterns in this plugin apply to both tools. File names change accordingly: mewt.toml → muton.toml, mewt.sqlite → muton.sqlite.

What It Does

Walks through a 5-phase configuration workflow:

1. Initialize and validate targets — run mewt init, review auto-generated config, fix include/ignore patterns
2. Generate mutants and assess scope — count mutants, time the test command, estimate campaign duration
3. Decide on optimization — choose between full run, targeted components, high/medium severity only, or two-phase campaign
4. Validate test command and timeout — verify the command works; set manual timeout for recompilation-heavy languages (Solidity/Foundry, heavy C++)
5. Final validation checklist — confirm config, mutant count, target selection, and timeout before running

When to Use

• Setting up a new mutation testing campaign
• Optimizing a campaign that would take too long to run
• Diagnosing why no mutants are generated or why the test command fails

Prerequisites

• mewt v3.0.0+ or muton v3.0.0+ installed
• A test suite runnable from the command line
• Source code in a supported language:
  • mewt: Rust, Solidity, Go, TypeScript, JavaScript
  • muton: Tact, Tolk, FunC (TON smart contract languages)

Example Usage

User: "Help me set up mewt for this Solidity project"
User: "Configure muton for this FunC codebase"
User: "My mewt campaign would take 30 hours — how do I optimize it?"
→ Guides through configuration, scope assessment, and optimization

References

• mewt GitHub Repository
• Use mutation testing to find the bugs your tests don't catch — Trail of Bits blog post