Cosmic Ray vs mutator
| Cosmic Ray | mutator | |
|---|---|---|
| Free plan | No | No |
| Free trial | No | No |
| Paid from | — | — |
| Open source | No | No |
| Platforms | Linux, self-hosted | — |
| Free plan | Yes | Yes |
| Supported languages | Python 3 | R |
| Test frameworks | unittest, pytest, nose | testthat; tinytest; generic installed-tests fallback |
| Incremental analysis | Yes | — |
| Parallel execution | Yes | Yes |
| Surviving mutant reports | Yes | Yes |
| Mutation operators | binary operator replacement; boolean replacement; break/continue replacement; comparison operator replacement; exception replacement; keyword replacement; number replacement; decorator removal; unary operator replacement; zero-iteration for loops | Arithmetic (+/- and */), comparison (==/!=, </>, <=/>=), logical (&/|, &&/||, ! and condition negation), assignment and call values, scalar constants, return values, statement deletion |
| Mutation quality gate | — | Yes |
Both are listed in Best Mutation Testing Tools. On Samsung Mobile US Press, Cosmic Ray scores higher on our published basis.