Gambit vs Muter

Gambit is a free, open-source mutation testing tool for Solidity projects. It generates altered contract versions, called mutants, to measure whether a test suite or formal verification specification detects faults. Gambit locates mutation points by traversing a program’s abstract syntax tree and applying predefined syntax transformations. A declarative configuration language lets users tailor mutations to specific parts of a program. Results can be viewed in a dashboard that summarizes mutant verification and calculates a specification score. Gambit can work with the Certora Prover to evaluate formal specifications; that workflow generates mutants and submits a verification job for each to Certora’s server. The command line includes `mutate` for generating mutants and `summary` for presenting them. A compatible `solc` binary is required for the project being mutated. Gambit supports Solidity and is listed for Linux, macOS, and Windows, though prebuilt binaries are available for Linux x86-64 and Mac; Windows and Linux ARM users must build from source. Function-call and swap-arguments-function mutation operators are disabled. The repository identifies the license as MIT. Certora directs product questions to its Help Desk channel on Discord.

Muter is a free, open-source mutation testing utility for Swift test suites on macOS. It changes code in a complete copy of the codebase, leaving the original untouched, then reports mutation scores for the full suite and individual files. Runs can happen in Xcode, from the command line or incrementally in continuous integration. Configuration covers Xcode projects, workspaces and Swift Package Manager. Reports can be plain text, JSON, HTML or Xcode issue navigator results, including surviving mutants. Documented operators replace relational operators, remove side effects, change logical connectors and swap ternary expressions. Muter supports projects tested with xcodebuild, including iOS, macOS, tvOS and watchOS applications, but the utility runs only on macOS 10.15 or newer. It supports Swift, not Objective-C. Any test target or suite can be used with Swift application code, although UI tests may take a long time. The project states that it has no network access and collects no analytics.