Cosmic Ray vs MutPy
Cosmic Ray
cosmic-ray.readthedocs.ioMutPy
github.comSide by side
| Figure | Cosmic Ray | MutPy |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | — | — |
| Open source | — | — |
| Linux | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 0 | 1 |
| Spec score · Mutation Testing Tools | 7.5 (#13) | 7.9 (#7) |
| Intended users | The documentation presents Cosmic Ray for Python projects whose teams want to check whether their test suites meaningfully verify code behavior. | PyPI classifies the package for developers and software testing. |
| License | The project repository identifies the software as MIT licensed. | The project is licensed under the Apache License, Version 2.0. |
| Purpose | Cosmic Ray is a mutation testing tool for Python 3 that makes small changes to production code and runs the test suite against each change. | MutPy is a mutation testing tool for Python source code that evaluates the quality of software tests. |
| Reports | Cosmic Ray provides `cr-report` for session summaries and `cr-html` for generating an HTML report that shows the mutation used. | MutPy can generate YAML and HTML reports and colorful console output. |
| Test runners | The documentation shows test commands using `unittest` and says `pytest` and `nose` can stop after a failing test with the `-x` option. | It supports unittest by default and pytest experimentally. |
Plans
In their own words
Cosmic Ray
Cosmic Ray has no write-up on Specifiction yet; its figures are above.
MutPy
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.