What it does

Mutahunter is a command-line tool for mutation testing that uses a language model. It produces mutated versions of your source code, runs your own test command against each one, and reports which mutants your tests killed and which survived. You point it at a source file and its test file, give it a test command and a model name, and it prints a run log followed by a summary. The README example runs a Maven test command against a Java class using an OpenAI key and the gpt-4o-mini model. The summary shows mutation coverage, the number of total, survived, killed, timeout and compile-error mutants, and the cost of the run in dollars. It installs with pip straight from the GitHub repository and needs Python 3.11 or newer. The project is licensed under AGPL-3.0, and the repository includes a Java Maven example.

Capabilities

Language-agnostic mutation testing driven by your own test command
Uses a language model to generate the mutants
Summary of mutation coverage with killed, survived, timeout and compile-error counts
Reports the cost of each run
Installs with pip and needs Python 3.11 or newer

When to use it

Checking whether your unit tests actually catch bugs
Finding weak spots in the tests for a specific source file
Trying mutation testing on projects in several programming languages