Fix psalm issues related to the user backend

- Reflect the actual return value returned by the implementation in the
  the interface. E.g. IUser|bool -> IUser|false
- Remove $hasLoggedIn parameter from private countUser implementation.
  Replace the two call with the equivalent countSeenUser
- getBackend is nuallable, add this to the interface
- Use backend interface to make psalm happy about call to undefined
  methods. Also helps with getting rid at some point of the old
  implementActions

Signed-off-by: Carl Schwan <carl@carlschwan.eu>

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/public/IUserManager.php b/lib/public/IUserManager.php
index e5c220af40c..77e2fc21a22 100644
--- a/lib/public/IUserManager.php
+++ b/lib/public/IUserManager.php
@@ -98,7 +98,7 @@ interface IUserManager {
 	 *
 	 * @param string $loginName
 	 * @param string $password
-	 * @return mixed the User object on success, false otherwise
+	 * @return IUser|false the User object on success, false otherwise
 	 * @since 8.0.0
 	 */
 	public function checkPassword($loginName, $password);
@@ -141,7 +141,7 @@ interface IUserManager {
 	 * @param string $uid
 	 * @param string $password
 	 * @throws \InvalidArgumentException
-	 * @return bool|\OCP\IUser the created user or false
+	 * @return false|\OCP\IUser the created user or false
 	 * @since 8.0.0
 	 */
 	public function createUser($uid, $password);
@@ -157,9 +157,9 @@ interface IUserManager {
 	public function createUserFromBackend($uid, $password, UserInterface $backend);
 
 	/**
-	 * returns how many users per backend exist (if supported by backend)
+	 * Get how many users per backend exist (if supported by backend)
 	 *
-	 * @return array an array of backend class as key and count number as value
+	 * @return array<string, int> an array of backend class name as key and count number as value
 	 * @since 8.0.0
 	 */
 	public function countUsers();