Provide simple PHPUnit integration

This is a simple PHPUnit integration for php-quickcheck.
It consists of a custom assertion and a static factory method.

To use this in a PHPUnit test, call

$this->assertThat(Gen::forAll($generators, $property), QCheckSpec::check(10));

Author: Vinai

src/QCheck/PHPUnit/Constraint/Prop.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace QCheck\PHPUnit\Constraint;
+
+use PHPUnit\Framework\Constraint\Constraint;
+use QCheck\Quick;
+
+class Prop extends Constraint
+{
+    /**
+     * @var int
+     */
+    private $size;
+    
+    /**
+     * @var array
+     */
+    private $opts;
+
+    public function __construct(int $n, array $opts = [])
+    {
+        $this->size = $n;
+        $this->opts = $opts;
+    }
+    
+    public static function check($n = 100, array $opts = [])
+    {
+        return new self($n, $opts);
+    }
+
+    public function evaluate($prop, string $description = '', bool $returnResult = false)
+    {
+        $result = Quick::check($this->size, $prop, $this->opts);
+        return parent::evaluate($result, $description, $returnResult);
+    }
+
+    protected function matches($other): bool
+    {
+        return @$other['result'] === true;
+    }
+
+    public function toString(): string
+    {
+        return 'property is true';
+    }
+
+    protected function failureDescription($other): string
+    {
+        return $this->toString();
+    }
+
+    protected function additionalFailureDescription($other): string
+    {
+        return sprintf(
+            "%sTests runs: %d, failing size: %d, seed: %s, smallest shrunk value(s):\n%s",
+            $this->extractExceptionMessage($other['result']),
+            $other['num_tests'],
+            $other['failing_size'],
+            $other['seed'],
+            var_export($other['shrunk']['smallest'], true)
+        );
+    }
+
+    private function extractExceptionMessage($other): string
+    {
+        return $other instanceof \Exception ? $other->getMessage() ."\n" : '';
+    }
+
+}