Added support for non-public enumeration constants.

Previously, non-public constants were being included in enumerations.
However, non-public constants cannot be accessed externally so they
should not be part of the enumeration. This patch adds only public
constants, whether declared explicitly or implicitly, to the
enumeration.

Author: Bilge

src/AbstractEnumeration.php

@@ -24,7 +24,33 @@ final protected static function initializeMembers()
         $reflector = new ReflectionClass(get_called_class());
 
         foreach ($reflector->getConstants() as $key => $value) {
-            new static($key, $value);
+            if (self::isPublicConstant($reflector, $key)) {
+                new static($key, $value);
+            }
         }
     }
+
+    /**
+     * Gets a value indicating whether the specified constant name is publicly accessible, according to the specified
+     * class reflector.
+     *
+     * This feature is not supported by all versions of PHP, so a check is performed to see if accessibility detection
+     * is available. This result of this check is statically cached so the check only occurs once per script lifetime.
+     *
+     * @param ReflectionClass $reflector Class reflector.
+     * @param string $name Constant name.
+     *
+     * @return bool True if the constant is public, otherwise false.
+     */
+    private static function isPublicConstant(ReflectionClass $reflector, $name)
+    {
+        static $methodExists;
+        $methodExists === null && $methodExists = method_exists($reflector, 'getReflectionConstants');
+
+        if (!$methodExists) {
+            return true;
+        }
+
+        return $reflector->getReflectionConstant($name)->isPublic();
+    }
 }

test/src/MixedAccessibilityEnumeration.php

@@ -0,0 +1,17 @@
+<?php
+
+use Eloquent\Enumeration\AbstractEnumeration;
+
+/**
+ * An enumeration whose members have different accessibility levels.
+ *
+ * @method static IMPLICIT_PUBLIC()
+ * @method static EXPLICIT_PUBLIC()
+ */
+final class MixedAccessibilityEnumeration extends AbstractEnumeration
+{
+    const IMPLICIT_PUBLIC = 'IMPLICIT_PUBLIC';
+    public const EXPLICIT_PUBLIC = 'EXPLICIT_PUBLIC';
+    protected const PROTECTED = 'PROTECTED';
+    private const PRIVATE = 'PRIVATE';
+}

test/suite/FunctionalTest.php

@@ -120,4 +120,18 @@ public function testPlanetExampleScriptOutput()
 
         $this->assertSame($expected, $actual);
     }
+
+    /**
+     * Tests that only public constants are included as enumeration members.
+     *
+     * @requires PHP 7.1
+     */
+    public function testMixedAccessibility()
+    {
+        $members = MixedAccessibilityEnumeration::members();
+
+        self::assertCount(2, $members);
+        self::assertArrayHasKey(MixedAccessibilityEnumeration::IMPLICIT_PUBLIC, $members);
+        self::assertArrayHasKey(MixedAccessibilityEnumeration::EXPLICIT_PUBLIC, $members);
+    }
 }