fixes #42: Enum::is() not working on inherited enumerations

Author: marc-mabe

src/MabeEnum/Enum.php

@@ -128,7 +128,8 @@ final public function getOrdinal()
      */
     final public function is($enum)
     {
-        return $this->value === $enum || ($enum instanceof static && $this->value === $enum->getValue());
+        return $this->value === $enum
+            || (($enum instanceof static || $this instanceof $enum) && $this->value === $enum->getValue());
     }
 
     /**

tests/MabeEnumTest/EnumTest.php

@@ -147,6 +147,21 @@ public function testIsBasic()
         $this->assertFalse($enum->is(EnumBasic2::ONE()));     // same value but different instance
     }
 
+    public function testIsExtended()
+    {
+        $enum1Basic     = EnumBasic::ONE();
+        $enum1Inherited = EnumInheritance::ONE();
+        $enumExtended   = EnumInheritance::INHERITANCE();
+
+        $this->assertTrue($enum1Basic->is($enum1Inherited));
+        $this->assertTrue($enum1Inherited->is($enum1Basic));
+
+        $this->assertFalse($enumExtended->is($enum1Basic));
+        $this->assertFalse($enumExtended->is($enum1Inherited));
+        $this->assertFalse($enum1Basic->is($enumExtended));
+        $this->assertFalse($enum1Inherited->is($enumExtended));
+    }
+
     public function testCallingGetOrdinalTwoTimesWillResultTheSameValue()
     {
         $enum = EnumBasic::get(EnumBasic::TWO);