fix: only alias if the alias exists

This adds a check to ensure that the alias exists as either a class,
interface, or trait before attempting to call `class_alias()`.

Author: weierophinney

CHANGELOG.md

@@ -2,6 +2,29 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
+## 0.2.2 - 2019-04-10
+
+### Added
+
+- Nothing.
+
+### Changed
+
+- Nothing.
+
+### Deprecated
+
+- Nothing.
+
+### Removed
+
+- Nothing.
+
+### Fixed
+
+- Added a check that the discovered alias exists as a class, interface, or trait
+  before attempting to call `class_alias()`.
+
 ## 0.2.1 - 2019-04-10
 
 ### Added

src/Autoloader.php

@@ -36,7 +36,10 @@ public static function load()
             }
 
             $alias = $classes[$check] . substr($class, strlen($check));
-            class_alias($alias, $class);
+
+            if (class_exists($alias) || interface_exists($alias) || trait_exists($alias)) {
+                class_alias($alias, $class);
+            }
         });
     }
 }