fast-check
7.1#1 in property-based testing toolsFree planFree planWebAPILinuxSelf-hosted
Visitfast-check vs PropEr
What both publish
| Fact | fast-check | PropEr |
|---|---|---|
| Integrations | The ecosystem lists official integrations for AVA, Jest, and Vitest, along with connectors for libraries such as Zod and io-ts. | The user guide explains using PropEr with EUnit and describes handling a shared ?LET macro and captured output. |
| Properties | Properties express predicates that must remain true for values produced by one or more arbitraries. | Properties are written using Erlang expressions with predefined macros. |
| Purpose | fast-check is a property-based testing library for JavaScript and TypeScript that generates inputs, runs assertions over many cases, and shrinks failures to smaller counterexamples. | PropEr is a tool for automated, semi-random, property-based testing of Erlang programs. |
| Support | The project invites code and non-code contributions, community help, and financial support through GitHub Sponsors or OpenCollective. | The developers invite comments, suggestions, feature requests, bug reports, patches, and other contributions through the project website, GitHub, or email. |
fast-check plans
- fast-checkFree
PropEr plans
- PropErFree
Pick fast-check if…
It suits JavaScript and TypeScript developers who want to check behavior across generated inputs, including stateful scenarios. Its runner-agnostic design can fit projects using a range of test runners.
Pick PropEr if…
PropEr is for developers testing Erlang programs, especially pure functions and library modules for stateful code. It suits users comfortable working with Erlang and a self-hosted tool.