diff --git a/auth.php b/auth.php
index e05f7f5..0f29683 100644
--- a/auth.php
+++ b/auth.php
@@ -112,7 +112,7 @@ class auth_plugin_userkey extends auth_plugin_base {
      * @throws \moodle_exception If gets running via CLI or AJAX call.
      */
     protected function redirect($url) {
-        if (CLI_SCRIPT or AJAX_SCRIPT) {
+        if (CLI_SCRIPT || AJAX_SCRIPT) {
             throw new moodle_exception('redirecterrordetected', 'auth_userkey', '', $url);
         }
 
diff --git a/classes/core_userkey_manager.php b/classes/core_userkey_manager.php
index 83e7c0b..bb05ed5 100644
--- a/classes/core_userkey_manager.php
+++ b/classes/core_userkey_manager.php
@@ -117,7 +117,7 @@ class core_userkey_manager implements userkey_manager_interface {
             throw new \moodle_exception('invalidkey');
         }
 
-        if (!empty($key->validuntil) and $key->validuntil < time()) {
+        if (!empty($key->validuntil) && $key->validuntil < time()) {
             throw new \moodle_exception('expiredkey');
         }
 
diff --git a/tests/auth_plugin_test.php b/tests/auth_plugin_test.php
index c17493d..8e8f64f 100644
--- a/tests/auth_plugin_test.php
+++ b/tests/auth_plugin_test.php
@@ -26,6 +26,8 @@ use external_value;
 /**
  * Tests for auth_plugin_userkey class.
  *
+ * @covers \auth_plugin_userkey
+ *
  * @package    auth_userkey
  * @copyright  2016 Dmitrii Metelkin (dmitriim@catalyst-au.net)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/tests/core_userkey_manager_test.php b/tests/core_userkey_manager_test.php
index fa113a7..a5d1709 100644
--- a/tests/core_userkey_manager_test.php
+++ b/tests/core_userkey_manager_test.php
@@ -22,6 +22,8 @@ namespace auth_userkey;
  * Key validation is fully covered in auth_plugin_test.php file.
  * TODO: write tests for validate_key() function.
  *
+ * @covers \auth_userkey\core_userkey_manager
+ *
  * @package    auth_userkey
  * @copyright  2016 Dmitrii Metelkin (dmitriim@catalyst-au.net)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/tests/externallib_test.php b/tests/externallib_test.php
index 1148b2b..ce42203 100644
--- a/tests/externallib_test.php
+++ b/tests/externallib_test.php
@@ -27,6 +27,8 @@ use context_system;
 /**
  * Tests for externallib.php.
  *
+ * @covers \auth_userkey_external
+ *
  * @package    auth_userkey
  * @copyright  2016 Dmitrii Metelkin (dmitriim@catalyst-au.net)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/version.php b/version.php
index eef3b4a..95b0b6a 100644
--- a/version.php
+++ b/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die;
 
-$plugin->version   = 2022081900;        // The current plugin version (Date: YYYYMMDDXX)
+$plugin->version   = 2022081900;        // The current plugin version (Date: YYYYMMDDXX).
 $plugin->release   = 2022081900;        // Match release exactly to version.
 $plugin->requires  = 2017051500;        // Requires Moodle 3.3 version.
 $plugin->component = 'auth_userkey';    // Full name of the plugin (used for diagnostics).