Side by side
Mutant vs Muter
Both stand on mutation testing tools. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan LinuxMac
Choose Mutant if you need Ruby mutation testing with the test frameworks and Ruby versions it supports, or Rails integration with parallel-worker database isolation. Public repositories can use the full feature set at no charge. Look elsewhere if your code relies on methods defined within closures, or if you need execution outside developer machines and CI.
Visit Mutant Free plan MacSelf-hosted
Muter offers several ways to run Swift mutation tests and inspect results, with no network access according to its project. Its scope is limited to Swift on macOS, and longer test runs may need planning.
Visit MuterThe facts
| Mutant | Muter | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Linux, Mac | Mac, Self-hosted |
| Lowest paid plan | Commercial yearly: $250 per developer a year | Free or on request |
| Plans published | 4 | 1 |
| Maker | Not published | Not published |
| Website | github.com | github.com |
| On mutation testing tools | #7 of 25 | #11 of 25 |
Mutant: what it does well
- Works with RSpec, Minitest and Test::Unit.
- Supports Ruby 3.2, 3.3, 3.4 and 4.0.
- Incremental mode supports CI workflows.
- Rails integration isolates parallel workers with PostgreSQL and SQLite.
- Free plan includes the full feature set for public repositories.
What to know first
- Cannot emit mutations for methods defined within closures.
- Commercial code requires a subscription per developer.
- Runs only on developers’ machines or in CI.
Muter: what it does well
- Reports mutation scores for suites and individual files.
- Runs in Xcode, the command line and incrementally in CI.
- Supports Xcode and Swift Package Manager tests.
- Works on a complete code copy.
What to know first
- Runs only on macOS 10.15 or later.
- Does not support Objective-C.
- Mutation testing can take a long time.
- Some @resultBuilder mutations may fail to compile.