Add PHP types to private methods and functions

Author: wouterj

User/InMemoryUserProvider.php

@@ -54,6 +54,10 @@ public function __construct(array $users = [])
      */
     public function createUser(UserInterface $user)
     {
+        if (!$user instanceof InMemoryUser) {
+            trigger_deprecation('symfony/security-core', '6.3', 'Passing users that are not instance of "%s" to "%s" is deprecated, "%s" given.', InMemoryUser::class, __METHOD__, get_debug_type($user));
+        }
+
         $userIdentifier = strtolower($user->getUserIdentifier());
         if (isset($this->users[$userIdentifier])) {
             throw new \LogicException('Another user with the same username already exists.');
@@ -90,8 +94,10 @@ public function supportsClass(string $class): bool
      * Returns the user by given username.
      *
      * @throws UserNotFoundException if user whose given username does not exist
+     *
+     * @return InMemoryUser change return type on 7.0
      */
-    private function getUser(string $username)/* : InMemoryUser */
+    private function getUser(string $username): UserInterface
     {
         if (!isset($this->users[strtolower($username)])) {
             $ex = new UserNotFoundException(sprintf('Username "%s" does not exist.', $username));