Cosmic Ray vs Infection
Cosmic Ray
cosmic-ray.readthedocs.io
Infection
infection.github.ioSide by side
| Figure | Cosmic Ray | Infection |
|---|---|---|
| Price from | — | — |
| Free plan | — | — |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 0 | 0 |
| Spec score · Mutation Testing Tools | 7.5 (#13) | 7.6 (#11) |
| License | The project repository identifies the software as MIT licensed. | The project is released under the BSD-3-Clause License. |
| Parallel execution | The HTTP distributor sends mutation and test requests to workers that can run locally or remotely; each worker needs its own copy of the code under test. | Tests for mutated code can run in parallel with the --threads option, including automatic CPU-core detection with --threads=max. |
| 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. | Infection mutates PHP source code and reports changes that a test suite fails to catch. |
In their own words
Cosmic Ray
Cosmic Ray has no write-up on Specifiction yet; its figures are above.
Infection
Infection is a PHP mutation-testing library that shows which changes a test suite fails to detect. It creates mutants using predefined operators, runs tests against changed code, and records killed and escaped mutants, errors, and timeouts. Its Mutation Score Indicator measures the share of generated mutations detected by tests; it also reports Mutation Code Coverage and Covered Code Mutation Score Indicator. Infection supports PHPUnit, PhpSpec, Codeception, and Testo, and runs from the command line at a project root. Teams can run mutated tests in parallel, focus analysis on touched lines or files, and set minimum mutation-score thresholds that fail a build. The homepage describes more than 100 mutators grouped into profiles and allows custom mutators. Optional PHPStan and Mago integrations can help catch escaped mutants involving type violations, dead code, and unreachable paths. Installation options include PHAR, Phive, Composer, Git, and Homebrew. A browser playground supports trying PHP code and tests without installing the tools. Infection is free under the BSD-3-Clause license and requires PHP 8.3 or newer plus Xdebug, phpdbg, or pcov.