Skillintermediate

PBT Libraries by Language

| Language | Library | Import/Setup | |----------|---------|--------------| | Python | Hypothesis | `from hypothesis import given, strategies as st` | | JavaScript/TypeScript | fast-check | `import fc from 'fast-check'` | | Rust | proptest | `use proptest::prelude::*` | | Go | rapid | `import "pgregory.net/rapid"` | | Java | jqwik | `@Property` annotations, `import net.jqwik.api.*` | | Scala | Sca

Claude Code Knowledge Pack7/10/2026

Overview

PBT Libraries by Language

Quick Reference

Language	Library	Import/Setup
Python	Hypothesis	`from hypothesis import given, strategies as st`
JavaScript/TypeScript	fast-check	`import fc from 'fast-check'`
Rust	proptest	`use proptest::prelude::*`
Go	rapid	`import "pgregory.net/rapid"`
Java	jqwik	`@Property` annotations, `import net.jqwik.api.*`
Scala	ScalaCheck	`import org.scalacheck._`
C#	FsCheck	`using FsCheck; using FsCheck.Xunit;`
Elixir	StreamData	`use ExUnitProperties`
Haskell	QuickCheck	`import Test.QuickCheck`
Clojure	test.check	`[clojure.test.check :as tc]`
Ruby	PropCheck	`require 'prop_check'`
Kotlin	Kotest	`io.kotest.property.*`
Swift	SwiftCheck	`import SwiftCheck` ⚠️ unmaintained
C++	RapidCheck	`#include <rapidcheck.h>`

Alternatives

Language	Alternative	Notes
Haskell	Hedgehog	Integrated shrinking, no type classes
Rust	quickcheck	Simpler API, per-type shrinking
Go	gopter	ScalaCheck-style, more explicit

Smart Contract Testing (EVM/Solidity)

Tool	Type	Description
Echidna	Fuzzer	Property-based fuzzer for EVM contracts
Medusa	Fuzzer	Next-gen fuzzer with parallel execution

// Echidna property example
function echidna_balance_invariant() public returns (bool) {
    return address(this).balance >= 0;
}

Installation:

# Echidna (via crytic toolchain)
pip install crytic-compile
# Download binary from https://github.com/crytic/echidna

# Medusa
go install github.com/crytic/medusa@latest

See secure-contracts.com for tutorials.

Installation

Python:

pip install hypothesis

JavaScript/TypeScript:

npm install fast-check

Rust (add to Cargo.toml):

[dev-dependencies]
proptest = "1.0"
# or for quickcheck:
quickcheck = "1.0"

Go:

go get pgregory.net/rapid
# or for gopter:
go get github.com/leanovate/gopter

Java (Maven):

<dependency>
  <groupId>net.jqwik</groupId>
  <artifactId>jqwik</artifactId>
  <version>1.9.3</version>
  <scope>test</scope>
</dependency>

Clojure (deps.edn):

{:deps {org.clojure/test.check {:mvn/version "1.1.2"}}}

Haskell:

cabal install QuickCheck
# or for Hedgehog:
cabal install hedgehog

Detecting Existing Usage

Search for PBT library imports in the codebase:

# Python
rg "from hypothesis import" --type py

# JavaScript/TypeScript
rg "from 'fast-check'" --type js --type ts

# Rust
rg "use proptest" --type rust

# Go
rg "pgregory.net/rapid" --type go

# Java
rg "@Property" --type java

# Clojure
rg "test.check" --type clojure

# Solidity (Echidna)
rg "echidna_" --glob "*.sol"