JSVerify vs Rapid
JSVerify
jsverify.github.ioRapid
pgregory.netSide by side
| Figure | JSVerify | Rapid |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Property-Based Testing Tools | 8.1 (#5) | 7.1 (#18) |
| Configuration | The check API documents options for test count, maximum generated value size, quiet output, and random generator state. | Rapid's options can be set with flags prefixed -rapid. or corresponding RAPID_ environment variables. |
| License | The GitHub repository identifies the project license as MIT. | Rapid is licensed under the Mozilla Public License Version 2.0. |
Plans
In their own words
JSVerify
JSVerify is a free, open-source property-based testing library for JavaScript, inspired by QuickCheck. It generates inputs and checks whether a stated property holds across them. When a check fails, it attempts to shrink the generated input into a smaller counterexample. Properties can return Promises, allowing asynchronous methods to be tested. JSVerify is framework agnostic; the project names Mocha, nodeunit, and Jasmine as examples. The README instructs users to install it with `npm install jsverify` and says TypeScript typings are provided, though TypeScript specs cannot use the type DSL. Documented defaults are 100 tests and a maximum generated-value size of 50. Options cover test count, maximum generated size, quiet output, and random generator state. Generated values are deterministic when using primitives from the random module, and the RNG state can be set. The project is maintained by phadej and licensed under MIT. Its official site points to the GitHub README for API and usage documentation. The README cautions that exposed utility functions may change incompatibly, including in patch releases.