Support PHP 8

Author: clue

README.md

@@ -115,7 +115,7 @@ $ composer require clue/graph:^0.9.1
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
 
 This project aims to run on any platform and thus does not require any PHP
-extensions and supports running on legacy PHP 5.3 through current PHP 7+ and
+extensions and supports running on legacy PHP 5.3 through current PHP 8+ and
 HHVM.
 It's *highly recommended to use PHP 7+* for this project.
 

composer.json

@@ -22,7 +22,7 @@
         }
     },
     "require": {
-        "php": "^7.0 || ^5.3"
+        "php": ">=5.3"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.3 || ^5.7 || ^4.8.35"

src/Exception/NegativeCycleException.php

@@ -14,8 +14,13 @@ class NegativeCycleException extends UnexpectedValueException implements Graph\E
      */
     private $cycle;
 
-    public function __construct($message, $code = NULL, $previous = NULL, Walk $cycle)
+    public function __construct($message, $code = NULL, $previous = NULL, Walk $cycle = null)
     {
+        // $cycle is required, but required argument may not appear after option arguments as of PHP 8
+        if ($cycle === null) {
+            throw new \InvalidArgumentException('Missing required cycle');
+        }
+
         parent::__construct($message, $code, $previous);
         $this->cycle = $cycle;
     }

tests/Exception/NegativeCycleExceptionTest.php

@@ -18,4 +18,10 @@ public function testConstructor()
         $this->assertEquals('test', $exception->getMessage());
         $this->assertEquals($cycle, $exception->getCycle());
     }
+
+    public function testConstructorThrowsWhenNoCycleIsGiven()
+    {
+        $this->setExpectedException('InvalidArgumentException');
+        new NegativeCycleException('test');
+    }
 }