MuJava vs MutPy

MuJava is a free, open-source tool for mutation testing of Java programs. It generates mutants for individual classes and packages, using 24 class-level operators as well as method-level operators, then runs tests against those mutants and evaluates mutation coverage. Tests must be JUnit test cases with public test classes and methods that call the classes under test; JUnit test suites are not supported. Equivalent mutants require manual identification, and the documentation says they typically make up 5% to 20% of mutants. Version 4 supports Java 1.6 language features, including generics, annotations, enumerations, varargs, enhanced for-each loops and static imports. Setup uses two JAR files and a configuration file, with Java CLASSPATH and PATH configuration. The documented workflow uses Java GUI applications; a command-line interface called muScript was released in March 2014, and an Eclipse plugin was created in 2007. The project is provided as-is, without guarantees of answers, repairs or improvements. It is available for Linux, macOS and Windows.

MutPy is a mutation testing tool for Python that checks whether a test suite catches changes to its source code. It creates mutations at the abstract syntax tree level, then runs tests to reveal which changes go undetected. The project describes compatibility with Python 3.3 and later. It uses unittest by default, while pytest support is experimental. Reports can be generated in YAML or HTML, and coverage analysis can restrict mutation to code exercised by tests. Users can also select or disable operators and sample a percentage of mutants. MutPy supports higher order mutations and includes standard and experimental operator sets. Installation is documented through pip from PyPI or from the repository source. The software is free at free and licensed under Apache License 2.0. PyPI lists version 0.6.1, released November 17, 2019, as the latest release. The README warns that disabling stdout can damage tests that interact with sys.stdout.