Add more strict typing for LocatorInterface

src/Locator/CallableLocator.php

@@ -34,10 +34,8 @@ public function __construct(callable $callable)
      * Returns a path to the file for given class name
      *
      * @param string $className Name of the class
-     *
-     * @return string|false Path to the file with given class or false if not found
      */
-    public function locateClass(string $className)
+    public function locateClass(string $className): false|string
     {
         return call_user_func($this->callable, ltrim($className, '\\'));
     }

src/Locator/ComposerLocator.php

@@ -49,10 +49,8 @@ public function __construct(ClassLoader $composerLoader = null)
      * Returns a path to the file for given class name
      *
      * @param string $className Name of the class
-     *
-     * @return string|false Path to the file with given class or false if not found
-     */
-    public function locateClass(string $className)
+     **/
+    public function locateClass(string $className): false|string
     {
         $filePath = $this->loader->findFile(ltrim($className, '\\'));
         if (!empty($filePath)) {

src/LocatorInterface.php

@@ -21,8 +21,6 @@ interface LocatorInterface
      * Returns a path to the file for given class name
      *
      * @param string $className Name of the class (with or without leading '\' FQCN)
-     *
-     * @return string|false Path to the file with given class or false if not found
      */
-    public function locateClass(string $className);
+    public function locateClass(string $className): false|string;
 }

tests/Stub/Issue44/Locator.php

@@ -10,7 +10,7 @@ class Locator implements LocatorInterface
     /**
      * @inheritdoc
      */
-    public function locateClass(string $className)
+    public function locateClass(string $className): false|string
     {
         if (ltrim($className, '\\') === ClassWithNamespace::class) {
             return __DIR__ . '/ClassWithNamespace.php';