jsproptest

jsproptest is a property-based testing (PBT) framework for JavaScript and TypeScript, drawing inspiration from libraries such as Haskell's QuickCheck and Python's Hypothesis. Property-based testing shifts the focus from example-based verification to defining universal properties or invariants that must hold true for an input domain.

Instead of manually crafting test cases for specific inputs, PBT allows you to describe the domain of inputs your function expects and the general characteristics of the output. jsproptest then generates hundreds or thousands of varied inputs, searching for edge cases or unexpected behaviors that violate your defined properties.

Getting Started

Installation

To add jsproptest to your project, run the following command:

npm install jsproptest --save-dev

This will install the package and add it to your devDependencies.

Key Features

jsproptest offers a rich set of features to empower your property-based testing efforts:

• Built-in Generators: A comprehensive suite of generators for common data types (integers, strings, arrays, objects, etc.) and the ability to create custom generators.
• Powerful Combinators: Flexible combinators to compose, transform, and filter generators, enabling the creation of complex and highly specific data structures.
• Automatic Shrinking: When a test fails, jsproptest automatically tries to find the smallest possible input that still causes the failure, making debugging much easier.
• Stateful Testing: Support for testing stateful systems by generating sequences of actions or commands and verifying invariants across these sequences.

Documentation

For comprehensive documentation, including core concepts, API reference, and advanced features, please visit GitHub Pages documentation.