diff --git a/.github/workflows/moodle-ci.yml b/.github/workflows/moodle-ci.yml
index e2cdd07..28b6f3d 100644
--- a/.github/workflows/moodle-ci.yml
+++ b/.github/workflows/moodle-ci.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         php: ['8.2']
-        moodle-branch: ['MOODLE_403_STABLE']
+        moodle-branch: ['MOODLE_404_STABLE']
         database: ['pgsql']
 
     steps:
@@ -17,7 +17,7 @@ jobs:
         run: docker run -p 5432:5432 -e POSTGRES_USER=postgres -e POSTGRES_HOST_AUTH_METHOD=trust -d postgres:14
 
       - name: Check out repository code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: plugin
 
@@ -28,29 +28,9 @@ jobs:
           ini-values: max_input_vars=5000
           coverage: none
 
-      - name: Get composer cache directory
-        id: composer-cache
-        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
-
-      - name: Composer cache
-        uses: actions/cache@v3
-        with:
-          path: ${{ steps.composer-cache.outputs.dir }}
-          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-composer-
-
-      - name: npm cache
-        uses: actions/cache@v3
-        with:
-          path: ~/.npm
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-            ${{ runner.os }}-node-
-
       - name: Initialise moodle-plugin-ci
         run: |
-          composer create-project -n --no-dev --prefer-dist moodlehq/moodle-plugin-ci ci ^3
+          composer create-project -n --no-dev --prefer-dist moodlehq/moodle-plugin-ci ci ^4
           echo $(cd ci/bin; pwd) >> $GITHUB_PATH
           echo $(cd ci/vendor/bin; pwd) >> $GITHUB_PATH
           sudo locale-gen en_AU.UTF-8
@@ -67,10 +47,6 @@ jobs:
         if: ${{ always() }}
         run: moodle-plugin-ci phplint
 
-      - name: PHP Copy/Paste Detector
-        if: ${{ always() }}
-        run: moodle-plugin-ci phpcpd
-
       - name: PHP Mess Detector
         if: ${{ always() }}
         run: moodle-plugin-ci phpmd
@@ -82,7 +58,6 @@ jobs:
       - name: Moodle PHPDoc Checker
         if: ${{ always() }}
         run: moodle-plugin-ci phpdoc
-        continue-on-error: true
 
       - name: Validating
         if: ${{ always() }}
@@ -108,30 +83,20 @@ jobs:
       fail-fast: false
       matrix:
         php: ['8.0', '8.1', '8.2']
-        moodle-branch: ['MOODLE_401_STABLE', 'MOODLE_402_STABLE', 'MOODLE_403_STABLE']
+        moodle-branch: ['MOODLE_401_STABLE', 'MOODLE_402_STABLE', 'MOODLE_403_STABLE', 'MOODLE_404_STABLE']
         database: ['mariadb', 'pgsql']
         exclude:
+          - php: '8.0'
+            moodle-branch: 'MOODLE_404_STABLE'
           - php: '8.2'
             moodle-branch: 'MOODLE_401_STABLE'
         include:
           - php: '7.4'
-            moodle-branch: 'MOODLE_39_STABLE'
-            database: 'mariadb'
-          - php: '7.4'
-            moodle-branch: 'MOODLE_39_STABLE'
-            database: 'pgsql'
-          - php: '8.0'
-            moodle-branch: 'MOODLE_311_STABLE'
-            database: 'mariadb'
-          - php: '8.0'
-            moodle-branch: 'MOODLE_311_STABLE'
+            moodle-branch: 'MOODLE_401_STABLE'
             database: 'pgsql'
-          - php: '8.0'
-            moodle-branch: 'MOODLE_400_STABLE'
+          - php: '7.4'
+            moodle-branch: 'MOODLE_401_STABLE'
             database: 'mariadb'
-          - php: '8.0'
-            moodle-branch: 'MOODLE_400_STABLE'
-            database: 'pgsql'
 
     steps:
       - name: Start MariaDB
@@ -143,7 +108,7 @@ jobs:
         run: docker run -p 5432:5432 -e POSTGRES_USER=postgres -e POSTGRES_HOST_AUTH_METHOD=trust -d postgres:14
 
       - name: Check out repository code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: plugin
 
@@ -154,24 +119,6 @@ jobs:
           ini-values: max_input_vars=5000
           coverage: none
 
-      - name: Get composer cache directory
-        id: composer-cache
-        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
-      - name: Composer cache
-        uses: actions/cache@v3
-        with:
-          path: ${{ steps.composer-cache.outputs.dir }}
-          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-composer-
-      - name: npm cache
-        uses: actions/cache@v3
-        with:
-          path: ~/.npm
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-            ${{ runner.os }}-node-
-
       - name: Initialise moodle-plugin-ci
         run: |
           composer create-project -n --no-dev --prefer-dist moodlehq/moodle-plugin-ci ci ^3
@@ -194,3 +141,15 @@ jobs:
       - name: Behat features
         if: ${{ always() }}
         run: moodle-plugin-ci behat --profile chrome --auto-rerun 0
+
+      # This step allows to upload Behat faildump (screenshots) as workflow artifact,
+      # so it can be downloaded and inspected. You don't need this step if you
+      # are not running Behat test. Artifact will be retained for 7 days.
+      - name: Upload Behat Faildump
+        if: ${{ failure() && steps.behat.outcome == 'failure' }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: Behat Faildump (${{ join(matrix.*, ', ') }})
+          path: ${{ github.workspace }}/moodledata/behat_dump
+          retention-days: 7
+          if-no-files-found: ignore
diff --git a/backup/moodle2/backup_groupmembers_stepslib.php b/backup/moodle2/backup_groupmembers_stepslib.php
index 8829212..e58a124 100644
--- a/backup/moodle2/backup_groupmembers_stepslib.php
+++ b/backup/moodle2/backup_groupmembers_stepslib.php
@@ -27,17 +27,20 @@
  */
 class backup_groupmembers_activity_structure_step extends backup_activity_structure_step {
 
+    /**
+     * Define structure for backup step.
+     */
     protected function define_structure() {
 
         // To know if we are including userinfo.
         $userinfo = $this->get_setting_value('userinfo');
 
         // Define each element separated.
-        $groupmembers = new backup_nested_element('groupmembers', array('id'),
-                array('name', 'intro', 'introformat', 'listgroupingid', 'showgroups', 'showemail', 'timemodified'));
+        $groupmembers = new backup_nested_element('groupmembers', ['id'],
+                ['name', 'intro', 'introformat', 'listgroupingid', 'showgroups', 'showemail', 'timemodified']);
 
         // Define sources.
-        $groupmembers->set_source_table('groupmembers', array('id' => backup::VAR_ACTIVITYID));
+        $groupmembers->set_source_table('groupmembers', ['id' => backup::VAR_ACTIVITYID]);
 
         // Define id annotations.
 
diff --git a/backup/moodle2/restore_groupmembers_activity_task.class.php b/backup/moodle2/restore_groupmembers_activity_task.class.php
index 62b1533..666ae2f 100644
--- a/backup/moodle2/restore_groupmembers_activity_task.class.php
+++ b/backup/moodle2/restore_groupmembers_activity_task.class.php
@@ -15,6 +15,9 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ *  Groupmembers restore task that provides all the settings and steps to perform one
+ *  complete restore of the activity
+ *
  * @package    mod_groupmembers
  * @copyright  2019 Justus Dieckmann WWU
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -49,9 +52,9 @@ protected function define_my_steps() {
      * processed by the link decoder
      */
     public static function define_decode_contents() {
-        $contents = array();
+        $contents = [];
 
-        $contents[] = new restore_decode_content('groupmembers', array('intro'), 'groupmembers');
+        $contents[] = new restore_decode_content('groupmembers', ['intro'], 'groupmembers');
 
         return $contents;
     }
@@ -61,7 +64,7 @@ public static function define_decode_contents() {
      * to the activity to be executed by the link decoder
      */
     public static function define_decode_rules() {
-        $rules = array();
+        $rules = [];
 
         $rules[] = new restore_decode_rule('GROUPMEMBERVIEWBYID', '/mod/groupmember/view.php?id=$1', 'course_module');
         $rules[] = new restore_decode_rule('GROUPMEMBERINDEX', '/mod/groupmember/index.php?id=$1', 'course');
@@ -77,7 +80,7 @@ public static function define_decode_rules() {
      * of {@link restore_log_rule} objects
      */
     public static function define_restore_log_rules() {
-        $rules = array();
+        $rules = [];
 
         $rules[] = new restore_log_rule('groupmembers', 'view', 'view.php?id={course_module}', '{groupmembers}');
 
@@ -95,7 +98,7 @@ public static function define_restore_log_rules() {
      * activity level. All them are rules not linked to any module instance (cmid = 0)
      */
     public static function define_restore_log_rules_for_course() {
-        $rules = array();
+        $rules = [];
 
         $rules[] = new restore_log_rule('groupmembers', 'view all', 'index.php?id={course}', null);
 
diff --git a/backup/moodle2/restore_groupmembers_stepslib.php b/backup/moodle2/restore_groupmembers_stepslib.php
index e1df6b5..2b0cd53 100644
--- a/backup/moodle2/restore_groupmembers_stepslib.php
+++ b/backup/moodle2/restore_groupmembers_stepslib.php
@@ -15,29 +15,33 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Structure step to restore one groupmembers activity
  * @package    mod_groupmembers
  * @copyright  2019 Justus Dieckmann WWU
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-/**
- * Define all the restore steps that will be used by the restore_groupmembers_activity_task
- */
-
 /**
  * Structure step to restore one groupmembers activity
  */
 class restore_groupmembers_activity_structure_step extends restore_activity_structure_step {
 
+    /**
+     * Define structure of restore step.
+     */
     protected function define_structure() {
 
-        $paths = array();
+        $paths = [];
         $paths[] = new restore_path_element('groupmembers', '/activity/groupmembers');
 
         // Return the paths wrapped into standard activity structure.
         return $this->prepare_activity_structure($paths);
     }
 
+    /**
+     * Restore groupmember activity.
+     * @param $data
+     */
     protected function process_groupmembers($data) {
         global $DB;
 
@@ -50,6 +54,9 @@ protected function process_groupmembers($data) {
         $this->apply_activity_instance($newitemid);
     }
 
+    /**
+     * Restore related files after execute.
+     */
     protected function after_execute() {
         // Add groupmembers related files, no need to match by itemname (just internally handled context).
         $this->add_related_files('mod_groupmembers', 'intro', null);
diff --git a/classes/event/course_module_viewed.php b/classes/event/course_module_viewed.php
index 71c3501..561dfee 100644
--- a/classes/event/course_module_viewed.php
+++ b/classes/event/course_module_viewed.php
@@ -55,6 +55,6 @@ protected function init() {
      * @return array Mapping according to the definition above
      */
     public static function get_objectid_mapping() {
-        return array('db' => 'groupmembers', 'restore' => 'groupmembers');
+        return ['db' => 'groupmembers', 'restore' => 'groupmembers'];
     }
 }
diff --git a/classes/groups.php b/classes/groups.php
index 4d6a36d..f23b41e 100644
--- a/classes/groups.php
+++ b/classes/groups.php
@@ -47,7 +47,7 @@ class groups {
      *      'group' => \stdClass, 'members' => array[\stdClass], 'ismember' => bool ]
      */
     public static function get_groups_and_members($courseid, $groupingid, $userid, $onlyown) {
-        $groupsandmembers = array();
+        $groupsandmembers = [];
 
         // Fetch relevant groups.
         if ($onlyown) {
@@ -66,11 +66,11 @@ public static function get_groups_and_members($courseid, $groupingid, $userid, $
 
             // Get members of group.
             $members = groups_get_members($group->id);
-            $groupsandmembers[] = array(
+            $groupsandmembers[] = [
                 'group' => $group,
                 'members' => $members,
-                'ismember' => $ismember
-            );
+                'ismember' => $ismember,
+            ];
         }
 
         return $groupsandmembers;
diff --git a/db/access.php b/db/access.php
index 6bd93c5..59bab7e 100644
--- a/db/access.php
+++ b/db/access.php
@@ -25,30 +25,30 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$capabilities = array(
+$capabilities = [
 
-    'mod/groupmembers:view' => array(
+    'mod/groupmembers:view' => [
         'captype' => 'read',
         'contextlevel' => CONTEXT_MODULE,
-        'archetypes' => array(
+        'archetypes' => [
             'guest' => CAP_ALLOW,
             'student' => CAP_ALLOW,
             'teacher' => CAP_ALLOW,
             'editingteacher' => CAP_ALLOW,
-            'manager' => CAP_ALLOW
-        )
-    ),
+            'manager' => CAP_ALLOW,
+        ],
+    ],
 
-    'mod/groupmembers:addinstance' => array(
+    'mod/groupmembers:addinstance' => [
         'riskbitmask' => RISK_XSS,
         'captype' => 'write',
         'contextlevel' => CONTEXT_COURSE,
-        'archetypes' => array(
+        'archetypes' => [
             'editingteacher' => CAP_ALLOW,
-            'manager' => CAP_ALLOW
-        ),
-        'clonepermissionsfrom' => 'moodle/course:manageactivities'
-    ),
-);
+            'manager' => CAP_ALLOW,
+        ],
+        'clonepermissionsfrom' => 'moodle/course:manageactivities',
+    ],
+];
 
 
diff --git a/db/events.php b/db/events.php
index e904108..b706563 100644
--- a/db/events.php
+++ b/db/events.php
@@ -25,7 +25,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$handlers = array();
+$handlers = [];
 
 /* List of events thrown from groupmembers module
 
diff --git a/db/upgrade.php b/db/upgrade.php
index 2facef9..11a4712 100644
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -23,8 +23,6 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined('MOODLE_INTERNAL') || die();
-
 /**
  * Upgrade script (no-op)
  * @param int $oldversion Version number before update
diff --git a/index.php b/index.php
index ac9b926..3051565 100644
--- a/index.php
+++ b/index.php
@@ -27,14 +27,14 @@
 require_once(__DIR__. '/lib.php');
 
 $id = required_param('id', PARAM_INT);   // Course ID.
-$PAGE->set_url('/mod/groupmembers/index.php', array('id' => $id));
+$PAGE->set_url('/mod/groupmembers/index.php', ['id' => $id]);
 
 $course = $DB->get_record('course', ['id' => $id], '*', MUST_EXIST);
 
 require_course_login($course);
 $PAGE->set_pagelayout('incourse');
 
-$eventdata = array('context' => context_course::instance($id));
+$eventdata = ['context' => context_course::instance($id)];
 $event = \mod_groupmembers\event\course_module_instance_list_viewed::create($eventdata);
 $event->add_record_snapshot('course', $course);
 $event->trigger();
@@ -54,7 +54,7 @@
 
 
 
-$linklist = array();
+$linklist = [];
 foreach ($instances as $instance) {
     $linklist[] = html_writer::link(new moodle_url('/mod/groupmembers/view.php', ['id' => $instance->coursemodule]),
         $instance->name);
diff --git a/lang/de/groupmembers.php b/lang/de/groupmembers.php
index 64e59b7..159f0ef 100644
--- a/lang/de/groupmembers.php
+++ b/lang/de/groupmembers.php
@@ -23,16 +23,20 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-$string['modulename'] = 'Gruppenmitglieder';
-$string['modulenameplural'] = 'Gruppenmitglieder';
-$string['modulename_help'] = 'Mit dem Gruppenmitglieder-Modul lassen sich die Mitglieder aller Gruppen einer Gruppierung auflisten.';
-$string['pluginname'] = 'Gruppenmitglieder';
-$string['pluginadministration'] = 'Gruppenmitglieder-Administration';
+$string['description'] = 'Beschreibung';
 $string['groupmembers:addinstance'] = 'Neue Gruppenmitglieder-Aktivität hinzufügen';
 $string['groupmembers:view'] = 'Gruppenmitglieder anzeigen';
 $string['groupmembersname'] = 'Name der Mitgliederliste';
-$string['description'] = 'Beschreibung';
 $string['listgrouping'] = 'Gruppierung';
+$string['mailhidden'] = 'E-Mail-Kontakt deaktiviert';
+$string['modulename'] = 'Gruppenmitglieder';
+$string['modulename_help'] = 'Mit dem Gruppenmitglieder-Modul lassen sich die Mitglieder aller Gruppen einer Gruppierung auflisten.';
+$string['modulenameplural'] = 'Gruppenmitglieder';
+$string['nogroupsavailable'] = 'Es sind derzeit keine Gruppen zur Anzeige hinterlegt.';
+$string['noowngroupsavailable'] = 'Du bist derzeit keiner Gruppe zugewiesen.';
+$string['pluginadministration'] = 'Gruppenmitglieder-Administration';
+$string['pluginname'] = 'Gruppenmitglieder';
+$string['privacy:metadata'] = 'Das Gruppenmitgliedermodul zeigt lediglich Informationen über Gruppen und Gruppierungen an, die an anderer Stelle unabhängig vom Modul gespeichert werden.';
 $string['setting_adminsettingsheading'] = 'Einstellungen';
 $string['setting_defaultsheading'] = 'Standardmäßige Voreinstellungen';
 $string['setting_showdeptinstdefault'] = 'Abteilungen und Institutionen anzeigen';
@@ -47,32 +51,28 @@
 $string['setting_showemaildefault_desc'] = 'Mit dieser Einstellung kontrollieren Sie die Voreinstellung von "E-Mail-Adressen anzeigen" innerhalb einer Aktivität.<br />Diese Einstellung wird nur berücksichtigt, wenn die Einstellung "E-Mail-Adressen anzeigen aktivieren" auch aktiviert ist.';
 $string['setting_showemailenable'] = 'E-Mail-Adressen anzeigen aktivieren';
 $string['setting_showemailenable_desc'] = 'Mit dieser Einstellung kontrollieren Sie ob die Anzeige von E-Mail-Adressen innerhalb einer Aktivität möglich ist oder nicht.';
+$string['setting_showgroupsdefault'] = 'Anzuzeigende Gruppen';
+$string['setting_showgroupsdefault_desc'] = 'Mit dieser Einstellung kontrollieren Sie die Voreinstellung von "Anzuzeigende Gruppen" innerhalb einer Aktivität.';
 $string['setting_showphonedefault'] = 'Telefonnummern anzeigen';
 $string['setting_showphonedefault_desc'] = 'Mit dieser Einstellung kontrollieren Sie die Voreinstellung von "Telefonnummern anzeigen" innerhalb einer Aktivität.<br />Diese Einstellung wird nur berücksichtigt, wenn die Einstellung "E-Mail-Adressen anzeigen aktivieren" auch aktiviert ist.';
 $string['setting_showphoneenable'] = 'ETelefonnummern anzeigen aktivieren';
 $string['setting_showphoneenable_desc'] = 'Mit dieser Einstellung kontrollieren Sie ob die Anzeige von Telefonnummern innerhalb einer Aktivität möglich ist oder nicht.';
-$string['setting_showgroupsdefault'] = 'Anzuzeigende Gruppen';
-$string['setting_showgroupsdefault_desc'] = 'Mit dieser Einstellung kontrollieren Sie die Voreinstellung von "Anzuzeigende Gruppen" innerhalb einer Aktivität.';
-$string['showgroups'] = 'Anzuzeigende Gruppen';
-$string['showgroups:all'] = 'Alle Gruppen der Gruppierung';
-$string['showgroups:own'] = 'Nur die eigene Gruppe';
 $string['showdeptinst'] = 'Abteilungen und Institutionen anzeigen';
 $string['showdesc'] = 'Beschreibungen anzeigen';
 $string['showemail'] = 'E-Mail-Adressen anzeigen';
+$string['showemail:allgroups'] = 'Für alle Gruppen anzeigen';
 $string['showemail:no'] = 'Nein, nur interne Nachrichten';
 $string['showemail:owngroup'] = 'Für die eigene Gruppe anzeigen';
-$string['showemail:allgroups'] = 'Für alle Gruppen anzeigen';
+$string['showfield:allgroups'] = 'Für alle Gruppen anzeigen';
 $string['showfield:no'] = 'Nein';
 $string['showfield:owngroup'] = 'Für die eigene Gruppe anzeigen';
-$string['showfield:allgroups'] = 'Für alle Gruppen anzeigen';
+$string['showgroups'] = 'Anzuzeigende Gruppen';
+$string['showgroups:all'] = 'Alle Gruppen der Gruppierung';
+$string['showgroups:own'] = 'Nur die eigene Gruppe';
 $string['showphone'] = 'Telefonnummern anzeigen';
-$string['user:fullname'] = 'Vorname / Nachname';
 $string['user:contact'] = 'Kontakt';
 $string['user:deptinst'] = 'Abteilung und Institution';
 $string['user:desc'] = 'Beschreibung';
 $string['user:descsummary'] = 'Beschreibung von {$a}';
+$string['user:fullname'] = 'Vorname / Nachname';
 $string['user:phone'] = 'Telefon';
-$string['noowngroupsavailable'] = 'Du bist derzeit keiner Gruppe zugewiesen.';
-$string['nogroupsavailable'] = 'Es sind derzeit keine Gruppen zur Anzeige hinterlegt.';
-$string['mailhidden'] = 'E-Mail-Kontakt deaktiviert';
-$string['privacy:metadata'] = 'Das Gruppenmitgliedermodul zeigt lediglich Informationen über Gruppen und Gruppierungen an, die an anderer Stelle unabhängig vom Modul gespeichert werden.';
diff --git a/lang/en/groupmembers.php b/lang/en/groupmembers.php
index 849e9ea..69d6c1a 100644
--- a/lang/en/groupmembers.php
+++ b/lang/en/groupmembers.php
@@ -23,16 +23,20 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-$string['modulename'] = 'Group Members';
-$string['modulenameplural'] = 'Group Members';
-$string['modulename_help'] = 'Use the Group Members module to list the members of all groups in one selected grouping.';
-$string['pluginname'] = 'Group Members';
-$string['pluginadministration'] = 'Group Members administration';
+$string['description'] = 'Description';
 $string['groupmembers:addinstance'] = 'Add a new list of group members';
 $string['groupmembers:view'] = 'View group members';
 $string['groupmembersname'] = 'Name of members list';
-$string['description'] = 'Description';
 $string['listgrouping'] = 'Grouping';
+$string['mailhidden'] = 'Mail contact disabled';
+$string['modulename'] = 'Group Members';
+$string['modulename_help'] = 'Use the Group Members module to list the members of all groups in one selected grouping.';
+$string['modulenameplural'] = 'Group Members';
+$string['nogroupsavailable'] = 'There are currently no groups to be displayed.';
+$string['noowngroupsavailable'] = 'You are currently not assigned to any group.';
+$string['pluginadministration'] = 'Group Members administration';
+$string['pluginname'] = 'Group Members';
+$string['privacy:metadata'] = 'The Group Members Activity only displays information about groups, but does not effect or store any personal data. The existing groups and groupings data is stored in other locations.';
 $string['setting_adminsettingsheading'] = 'Group Members settings';
 $string['setting_defaultsheading'] = 'Group Members default settings';
 $string['setting_showdeptinstdefault'] = 'Show department and institution';
@@ -47,32 +51,28 @@
 $string['setting_showemaildefault_desc'] = 'With this setting, you control the default value of the "Show e-mail addresses" module instance setting.<br />This setting will only be processed, if the "Enable showing e-mail addresses" is enabled.';
 $string['setting_showemailenable'] = 'Enable showing e-mail addresses';
 $string['setting_showemailenable_desc'] = 'With this setting, you control if showing e-mail addresses can be enabled within a module instance or not.';
+$string['setting_showgroupsdefault'] = 'Show groups';
+$string['setting_showgroupsdefault_desc'] = 'With this setting, you control the default value of the "Show groups" module instance setting.';
 $string['setting_showphonedefault'] = 'Show phone numbers';
 $string['setting_showphonedefault_desc'] = 'With this setting, you control the default value of the "Show phone numbers" module instance setting.<br />This setting will only be processed, if the "Enable showing phone numbers" is enabled.';
 $string['setting_showphoneenable'] = 'Enable showing phone numbers';
 $string['setting_showphoneenable_desc'] = 'With this setting, you control if showing phone numbers can be enabled within a module instance or not.';
-$string['setting_showgroupsdefault'] = 'Show groups';
-$string['setting_showgroupsdefault_desc'] = 'With this setting, you control the default value of the "Show groups" module instance setting.';
-$string['showgroups'] = 'Show groups';
-$string['showgroups:all'] = 'All groups of grouping';
-$string['showgroups:own'] = 'Only own group';
 $string['showdeptinst'] = 'Show department and institution';
 $string['showdesc'] = 'Show description';
 $string['showemail'] = 'Show e-mail addresses';
+$string['showemail:allgroups'] = 'For all groups';
 $string['showemail:no'] = 'No, only internal messages';
 $string['showemail:owngroup'] = 'Only for own group';
-$string['showemail:allgroups'] = 'For all groups';
+$string['showfield:allgroups'] = 'For all groups';
 $string['showfield:no'] = 'No';
 $string['showfield:owngroup'] = 'Only for own group';
-$string['showfield:allgroups'] = 'For all groups';
+$string['showgroups'] = 'Show groups';
+$string['showgroups:all'] = 'All groups of grouping';
+$string['showgroups:own'] = 'Only own group';
 $string['showphone'] = 'Show phone numbers';
-$string['user:fullname'] = 'First name / Surname';
 $string['user:contact'] = 'Contact';
 $string['user:deptinst'] = 'Department & Institution';
 $string['user:desc'] = 'Description';
 $string['user:descsummary'] = '{$a}\'s Description';
+$string['user:fullname'] = 'First name / Surname';
 $string['user:phone'] = 'Phone';
-$string['noowngroupsavailable'] = 'You are currently not assigned to any group.';
-$string['nogroupsavailable'] = 'There are currently no groups to be displayed.';
-$string['mailhidden'] = 'Mail contact disabled';
-$string['privacy:metadata'] = 'The Group Members Activity only displays information about groups, but does not effect or store any personal data. The existing groups and groupings data is stored in other locations.';
diff --git a/lib.php b/lib.php
index 8b1dedb..4622f69 100644
--- a/lib.php
+++ b/lib.php
@@ -148,10 +148,10 @@ function groupmembers_get_groupmembers($groupmembersid) {
 function groupmembers_view($groupmembers, $course, $cm, $context) {
 
     // Trigger course_module_viewed event.
-    $params = array(
+    $params = [
         'context' => $context,
-        'objectid' => $groupmembers->id
-    );
+        'objectid' => $groupmembers->id,
+    ];
 
     $event = \mod_groupmembers\event\course_module_viewed::create($params);
     $event->add_record_snapshot('course_modules', $cm);
diff --git a/mod_form.php b/mod_form.php
index 92a4856..2e1c73c 100644
--- a/mod_form.php
+++ b/mod_form.php
@@ -51,7 +51,7 @@ protected function definition() {
         // -------------------------------------------------------------------------------
         $mform->addElement('header', 'general', get_string('general', 'form'));
 
-        $mform->addElement('text', 'name', get_string('groupmembersname', 'groupmembers'), array('size' => '64'));
+        $mform->addElement('text', 'name', get_string('groupmembersname', 'groupmembers'), ['size' => '64']);
         if (!empty($CFG->formatstringstriptags)) {
             $mform->setType('name', PARAM_TEXT);
         } else {
@@ -66,33 +66,33 @@ protected function definition() {
         $mform->addElement('header', 'general', get_string('modulename', 'groupmembers'));
 
         // Groupings selector - used to select grouping for groups in activity.
-        $options = array();
-        if ($groupings = $DB->get_records('groupings', array('courseid' => $COURSE->id))) {
+        $options = [];
+        if ($groupings = $DB->get_records('groupings', ['courseid' => $COURSE->id])) {
             foreach ($groupings as $grouping) {
                 $options[$grouping->id] = format_string($grouping->name);
             }
         }
         core_collator::asort($options);
-        $options = array(0 => get_string('none')) + $options;
+        $options = [0 => get_string('none')] + $options;
         $mform->addElement('select', 'listgroupingid', get_string('listgrouping', 'groupmembers'), $options);
         $mform->addRule('listgroupingid', null, 'required', null, 'client');
 
         // Group visibility selector - used to decide which groups to show in listing.
-        $options = array(
+        $options = [
             GROUPMEMBERS_SHOWGROUPS_ALL => get_string('showgroups:all', 'groupmembers'),
             GROUPMEMBERS_SHOWGROUPS_OWN => get_string('showgroups:own', 'groupmembers'),
-        );
+        ];
         $mform->addElement('select', 'showgroups', get_string('showgroups', 'groupmembers'), $options);
         $mform->addRule('showgroups', null, 'required', null, 'client');
         $mform->setDefault('showgroups', $config->showgroupsdefault);
 
         // E-Mail visibility selector - used to decide whether e-mail adresses should be shown to other users.
         if ($config->showemailenable) {
-            $options = array(
+            $options = [
                 GROUPMEMBERS_SHOWEMAIL_NO => get_string('showemail:no', 'groupmembers'),
                 GROUPMEMBERS_SHOWEMAIL_OWNGROUP => get_string('showemail:owngroup', 'groupmembers'),
                 GROUPMEMBERS_SHOWEMAIL_ALLGROUPS => get_string('showemail:allgroups', 'groupmembers'),
-            );
+            ];
             $mform->addElement('select', 'showemail', get_string('showemail', 'groupmembers'), $options);
             $mform->addRule('showemail', null, 'required', null, 'client');
             $mform->setDefault('showemail', $config->showemaildefault);
@@ -100,11 +100,11 @@ protected function definition() {
 
         // Phone visibility selector - used to decide whether phone numbers should be shown to other users.
         if ($config->showphoneenable) {
-            $options = array(
+            $options = [
                 GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-            );
+            ];
             $mform->addElement('select', 'showphone', get_string('showphone', 'groupmembers'), $options);
             $mform->addRule('showphone', null, 'required', null, 'client');
             $mform->setDefault('showphone', $config->showphonedefault);
@@ -112,11 +112,11 @@ protected function definition() {
 
         // Department & Institution visibility selector - used to decide whether dept. and inst. should be shown to other users.
         if ($config->showdeptinstenable) {
-            $options = array(
+            $options = [
                 GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-            );
+            ];
             $mform->addElement('select', 'showdeptinst', get_string('showdeptinst', 'groupmembers'), $options);
             $mform->addRule('showdeptinst', null, 'required', null, 'client');
             $mform->setDefault('showdeptinst', $config->showdeptinstdefault);
@@ -124,11 +124,11 @@ protected function definition() {
 
         // Department & Institution visibility selector - used to decide whether dept. and inst. should be shown to other users.
         if ($config->showdescenable) {
-            $options = array(
+            $options = [
                 GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
                 GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-            );
+            ];
             $mform->addElement('select', 'showdesc', get_string('showdesc', 'groupmembers'), $options);
             $mform->addRule('showdesc', null, 'required', null, 'client');
             $mform->setDefault('showdesc', $config->showdescdefault);
diff --git a/renderer.php b/renderer.php
index 76554f8..906f00e 100644
--- a/renderer.php
+++ b/renderer.php
@@ -60,11 +60,11 @@ public function render_allgroups(array $groups, $showemail, $showphone, $showdep
             $showdesc = GROUPMEMBERS_SHOWFIELD_NO;
         }
 
-        $data = array(
-            'groups' => []
-        );
+        $data = [
+            'groups' => [],
+        ];
         foreach ($groups as $group) {
-            $members = array();
+            $members = [];
             foreach ($group['members'] as $member) {
                 $memberemail = null;
                 $memberemailtext = null;
@@ -108,10 +108,10 @@ public function render_allgroups(array $groups, $showemail, $showphone, $showdep
 
                     // Get data for additional fields if not hidden.
                     if ($showphone > 0) {
-                        $memberphone = implode(', ', array_filter(array($member->phone1, $member->phone2)));
+                        $memberphone = implode(', ', array_filter([$member->phone1, $member->phone2]));
                     }
                     if ($showdeptinst > 0) {
-                        $memberdeptinst = implode(', ', array_filter(array($member->department, $member->institution)));
+                        $memberdeptinst = implode(', ', array_filter([$member->department, $member->institution]));
                     }
                     if ($showdesc > 0 && $member->description) {
                         $memberdesc = $member->description;
@@ -121,7 +121,7 @@ public function render_allgroups(array $groups, $showemail, $showphone, $showdep
                     }
                 }
 
-                $members[] = array(
+                $members[] = [
                     'id' => $member->id,
                     'picture' => $this->output->user_picture($member),
                     'displayname' => fullname($member),
@@ -133,19 +133,19 @@ public function render_allgroups(array $groups, $showemail, $showphone, $showdep
                     'memberphone' => $memberphone,
                     'memberdeptinst' => $memberdeptinst,
                     'memberdesc' => $memberdesc,
-                    'membersummary' => $membersummary
-                );
+                    'membersummary' => $membersummary,
+                ];
             }
 
-            $data['groups'][] = array(
+            $data['groups'][] = [
                 'id' => $group['group']->id,
                 'name' => $group['group']->name,
                 'members' => $members,
                 'ismember' => $group['ismember'],
                 'showphone' => $showphone,
                 'showdeptinst' => $showdeptinst,
-                'showdesc' => $showdesc
-            );
+                'showdesc' => $showdesc,
+            ];
         }
         return $this->render_from_template('mod_groupmembers/allgroups', $data);
     }
diff --git a/settings.php b/settings.php
index 9050785..0d14c19 100644
--- a/settings.php
+++ b/settings.php
@@ -73,10 +73,10 @@
     $name = 'mod_groupmembers/showgroupsdefault';
     $title = get_string('setting_showgroupsdefault', 'mod_groupmembers', null, true);
     $description = get_string('setting_showgroupsdefault_desc', 'mod_groupmembers', null, true);
-    $options = array(
+    $options = [
             GROUPMEMBERS_SHOWGROUPS_ALL => get_string('showgroups:all', 'groupmembers'),
             GROUPMEMBERS_SHOWGROUPS_OWN => get_string('showgroups:own', 'groupmembers'),
-    );
+    ];
     $setting = new admin_setting_configselect($name, $title, $description, GROUPMEMBERS_SHOWGROUPS_ALL, $options);
     $settings->add($setting);
 
@@ -84,11 +84,11 @@
     $name = 'mod_groupmembers/showemaildefault';
     $title = get_string('setting_showemaildefault', 'mod_groupmembers', null, true);
     $description = get_string('setting_showemaildefault_desc', 'mod_groupmembers', null, true);
-    $options = array(
+    $options = [
             GROUPMEMBERS_SHOWEMAIL_NO => get_string('showemail:no', 'groupmembers'),
             GROUPMEMBERS_SHOWEMAIL_OWNGROUP => get_string('showemail:owngroup', 'groupmembers'),
             GROUPMEMBERS_SHOWEMAIL_ALLGROUPS => get_string('showemail:allgroups', 'groupmembers'),
-    );
+    ];
     $setting = new admin_setting_configselect($name, $title, $description, GROUPMEMBERS_SHOWEMAIL_NO, $options);
     $settings->add($setting);
 
@@ -96,11 +96,11 @@
     $name = 'mod_groupmembers/showphonedefault';
     $title = get_string('setting_showphonedefault', 'mod_groupmembers', null, true);
     $description = get_string('setting_showphonedefault_desc', 'mod_groupmembers', null, true);
-    $options = array(
+    $options = [
             GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-    );
+    ];
     $setting = new admin_setting_configselect($name, $title, $description, GROUPMEMBERS_SHOWFIELD_NO, $options);
     $settings->add($setting);
 
@@ -108,11 +108,11 @@
     $name = 'mod_groupmembers/showdeptinstdefault';
     $title = get_string('setting_showdeptinstdefault', 'mod_groupmembers', null, true);
     $description = get_string('setting_showdeptinstdefault_desc', 'mod_groupmembers', null, true);
-    $options = array(
+    $options = [
             GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-    );
+    ];
     $setting = new admin_setting_configselect($name, $title, $description, GROUPMEMBERS_SHOWFIELD_NO, $options);
     $settings->add($setting);
 
@@ -120,11 +120,11 @@
     $name = 'mod_groupmembers/showdescdefault';
     $title = get_string('setting_showdescdefault', 'mod_groupmembers', null, true);
     $description = get_string('setting_showdescdefault_desc', 'mod_groupmembers', null, true);
-    $options = array(
+    $options = [
             GROUPMEMBERS_SHOWFIELD_NO => get_string('showfield:no', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_OWNGROUP => get_string('showfield:owngroup', 'groupmembers'),
             GROUPMEMBERS_SHOWFIELD_ALLGROUPS => get_string('showfield:allgroups', 'groupmembers'),
-    );
+    ];
     $setting = new admin_setting_configselect($name, $title, $description, GROUPMEMBERS_SHOWFIELD_NO, $options);
     $settings->add($setting);
 
diff --git a/tests/groups_datastructure_test.php b/tests/groups_datastructure_test.php
index 78148e6..33fd096 100644
--- a/tests/groups_datastructure_test.php
+++ b/tests/groups_datastructure_test.php
@@ -23,7 +23,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined('MOODLE_INTERNAL') || die();
+namespace mod_groupmembers;
 
 /**
  * Test logic used by the renderer whether to show/hide particular elements
@@ -33,14 +33,15 @@
  * @copyright  2017 Jan C. Dageförde, WWU Münster
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class mod_groupmembers_groups_datastructure_testcase extends advanced_testcase {
+final class groups_datastructure_test extends advanced_testcase {
 
     /**
      * Test pair:
      * - show only own groups
      * - show regardless of grouping
+     * @covers \mod_groupmembers\groups::get_groups_and_members
      */
-    public function test_only_own_nogrouping() {
+    public function test_only_own_nogrouping(): void {
         $this->resetAfterTest();
         $dg = static::getDataGenerator();
 
@@ -60,8 +61,9 @@ public function test_only_own_nogrouping() {
      * Test pair:
      * - show only own groups
      * - limit to particular grouping
+     * @covers \mod_groupmembers\groups::get_groups_and_members
      */
-    public function test_only_own_withgrouping() {
+    public function test_only_own_withgrouping(): void {
         $this->resetAfterTest();
         $dg = static::getDataGenerator();
         list($courseid, $userid, $groupid, $groupingid) = $this->prepare_basic_data($dg);
@@ -84,8 +86,9 @@ public function test_only_own_withgrouping() {
      * Test pair:
      * - show all groups
      * - show regardless of grouping
+     * @covers \mod_groupmembers\groups::get_groups_and_members
      */
-    public function test_all_nogrouping() {
+    public function test_all_nogrouping(): void {
         $this->resetAfterTest();
         $dg = static::getDataGenerator();
         list($courseid, $userid, $groupid) = $this->prepare_basic_data($dg);
@@ -115,8 +118,9 @@ public function test_all_nogrouping() {
      * Test pair:
      * - show all groups
      * - limit to particular grouping
+     * @covers \mod_groupmembers\groups::get_groups_and_members
      */
-    public function test_all_withgrouping() {
+    public function test_all_withgrouping(): void {
         $this->resetAfterTest();
         $dg = static::getDataGenerator();
         list($courseid, $userid) = $this->prepare_basic_data($dg);
diff --git a/view.php b/view.php
index 0d3551a..bf54b31 100644
--- a/view.php
+++ b/view.php
@@ -27,7 +27,7 @@
 require_once(__DIR__. '/lib.php');
 
 $id = required_param('id', PARAM_INT);  // Course Module ID.
-$PAGE->set_url(new moodle_url('/mod/groupmembers/view.php', array('id' => $id)));
+$PAGE->set_url(new moodle_url('/mod/groupmembers/view.php', ['id' => $id]));
 
 // Load course module.
 if (! $cm = get_coursemodule_from_id('groupmembers', $id)) {
@@ -35,7 +35,7 @@
 }
 
 // Load corresponding course.
-if (! $course = $DB->get_record('course', array('id' => $cm->course))) {
+if (! $course = $DB->get_record('course', ['id' => $cm->course])) {
     throw new moodle_exception('coursemisconf');
 }