README

Property-based testing for PHP 8.4+, inspired by the Python Hypothesis library.

Features

• Property-Based Testing: Define properties that should always be true, and let the library find counter-examples.
• Smart Shrinking: When a failure is found, the library automatically shrinks the input to the smallest possible failing case.
• PHP 8.4+ Attributes: Use the #[Given] attribute for clean, declarative test definitions.
• PHPUnit Integration: Seamlessly integrates with PHPUnit 11+.
• Zero Runtime Dependencies: Lightweight and fast.

Installation

composer require fr3on/php-hypothesis

Quick Start

use Fr3on\Hypothesis\PHPUnit\PropertyTestCase;
use Fr3on\Hypothesis\Attribute\Given;
use Fr3on\Hypothesis\Shape\ListShape;
use Fr3on\Hypothesis\Shape\IntegerShape;

class SortingTest extends PropertyTestCase
{
    #[Given(new ListShape(new IntegerShape()))]
    public function prop_sort_is_idempotent(array $list): void
    {
        $sorted = $list;
        sort($sorted);
        
        $doubleSorted = $sorted;
        sort($doubleSorted);
        
        $this->assertSame($sorted, $doubleSorted);
    }
}

How it Works

1. Generation: The library generates random data based on the "Shapes" you define (Integer, String, List, etc.).
2. Execution: Your test runs multiple times (default 100) with different inputs.
3. Shrinking: If a failure occurs, the library iteratively simplifies the input to find the "minimal reproducible case".
4. Result: You get a clear report of exactly what caused the property to fail.

License

MIT