muttest

Windows · Mac · Linux

Freedom report

Two barsScore 5.6

muttest is ranked #6 of 25 in mutation testing tools on Freedom251. It runs on Linux, macOS, Windows.

Compared on mutation testing tools

Free plan: Yes
Supported languages: R
Test frameworks: testthat; cucumber
Incremental analysis: Yes
Surviving mutant reports: Yes
Mutation quality gate: Yes
Mutation operators: Binary operators; arithmetic operators; comparison operators; logical operators; boolean literals; NA/NULL literals; numeric literals; string literals; condition negation; function-call names; index increments/decrements; explicit return values

Purpose: muttest mutates R code and runs tests to measure how often the tests catch those changes.
Mutation score: The package reports a percentage score for how often tests catch mutations.
Configurable mutations: Users choose what code changes to make and where to make them.
R test workflow: The maker describes muttest as mutation testing for R and shows tests under the testthat framework.
Mutation examples: The maker’s examples include changing comparison operators to expose untested boundary cases.
Reporting: The package includes HTML and JSON reporting.
Parallel execution: The maker’s July 2026 update describes parallel execution as a muttest capability.
CI: The documentation index links a guide to running muttest in CI, including GitHub Actions and score badges.
Install: The package page provides an R install.packages command using the maker’s r-universe repository and CRAN.
Supported build platforms: The package page lists successful checks for Linux, macOS, Windows, and WebAssembly targets.
Requirements: The documentation index lists testthat among muttest’s dependencies.
Maker: The maker identifies himself as Jakub Sobolewski, a software engineer specializing in R and Shiny.
File feedback: The tool reports which files need stronger assertions.
Mutators: Available mutators include operator, boolean, NA or NULL, function-call, string, numeric, index, condition, negation, and return-value changes.

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