The Mutorium Labs Book of Mutation Testing

A programmer-focused book on mutation testing — from fundamentals to Rust and ZK circuits.

This is a work in progress. Chapters will be published as blog posts first. As the library grows, this page acts as a living table of contents.

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Table of contents

Each chapter is designed to be practical: minimal theory, concrete examples, exercises, and reusable patterns.

Module 0 — Foundations

The mental models and workflow you need to use mutation testing as a measurement instrument (not just another tool).

  1. What Is Mutation Testing? A Practical Introduction Published
  2. Coverage vs Mutation: when 100% coverage lies Planned
  3. How to read mutation results (killed / survived / invalid) Planned
  4. Equivalent mutants: when “survived” doesn’t mean weak tests Planned
  5. How to systematically kill survivors (assertions, boundaries, invariants) Planned
  6. Swiss Cheese Model of Web3 Security: Where Mutation Testing Fits Published

    Context chapter (optional): where mutation testing fits among tests, fuzzing, audits, and formal methods.

Module 1 — Mutation Testing in Rust

Practical mutation testing with cargo-mutants — plus the testing patterns that reliably turn survivors into killed mutants.

  1. cargo-mutants Quickstart (real workflow, not a tour) Published
  2. Mutation genres and what they reveal Planned
  3. Reports & automation (mutants.out, JSON, diffs, CI gating) Planned
  4. Scaling: flakiness, timeouts, determinism, sharding Planned
  5. Snapshots as a force multiplier (insta + mutation testing) Published

Module 2 — Mutation Testing for ZK Circuits (Noir) with zk-mutant

Source-level mutations for Noir projects, CI-friendly outputs, and (eventually) high-signal operator design for circuits.

  1. Why mutation testing is especially useful for circuits Planned
  2. zk-mutant workflow mastery (scan / list / run + deterministic CI) Planned
  3. Artifacts & consumption (run.json, mutants.json, outcomes.json) Planned
  4. Announcing zk-mutant v0.1.0 Published

    Current state of the tool + artifacts + near-term roadmap.

  5. High-signal Noir mutation operators (taxonomy by bug class) Planned
  6. Equivalent mutants in ZK + how to handle them Planned
  7. Performance + roadmap (grounded, practical) Planned

Future modules

Planned, but not started. We’ll add these once the core modules above are solid.

  1. Mutation Testing for Solidity (planned) Planned

How to read this book