diff --git a/.github/workflows/moodle-ci.yml b/.github/workflows/moodle-ci.yml
index ebf9c26..618bd74 100644
--- a/.github/workflows/moodle-ci.yml
+++ b/.github/workflows/moodle-ci.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         php: ['8.2']
-        moodle-branch: ['MOODLE_403_STABLE']
+        moodle-branch: ['MOODLE_404_STABLE']
         database: ['pgsql']
 
     steps:
@@ -20,7 +20,7 @@ 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
 
@@ -36,29 +36,9 @@ 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
@@ -75,10 +55,6 @@ 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
@@ -86,7 +62,6 @@ jobs:
       - name: Moodle Code Checker
         if: ${{ always() }}
         run: moodle-plugin-ci codechecker
-        continue-on-error: true
 
       - name: Moodle PHPDoc Checker
         if: ${{ always() }}
@@ -117,30 +92,20 @@ 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
@@ -152,7 +117,7 @@ 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
 
@@ -163,24 +128,6 @@ 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
@@ -202,4 +149,16 @@ jobs:
 
       - name: Behat features
         if: ${{ always() }}
-        run: moodle-plugin-ci behat --auto-rerun 0
+        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/block_groups.php b/block_groups.php
index 1b38fde..bff5b93 100644
--- a/block_groups.php
+++ b/block_groups.php
@@ -36,8 +36,8 @@
  * @copyright 2016/17 N Herrmann
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class block_groups extends block_base
-{
+class block_groups extends block_base {
+
     /**
      * Initializes the block.
      */
@@ -83,7 +83,7 @@ public function get_content() {
      * @return array of applicable formats.
      */
     public function applicable_formats() {
-        return array('course-view' => true, 'mod' => false, 'my' => false);
+        return ['course-view' => true, 'mod' => false, 'my' => false];
     }
     /**
      * Returns a html representation of all existing groups and groupings
@@ -91,25 +91,25 @@ public function applicable_formats() {
      * @return string html-string
      */
     private function get_content_teaching() {
-        global  $COURSE, $PAGE, $DB, $CFG;
+        global  $COURSE, $DB;
         $courseid = $COURSE->id;
         // Array to save all groups.
         $allgroups = groups_get_all_groups($courseid);
         // Array to save all groupings.
         $allgroupings = groups_get_all_groupings($courseid);
         $content = '';
-        /* @var $renderer block_groups_renderer */
-        $renderer = $PAGE->get_renderer('block_groups');
+        /** @var block_groups_renderer $renderer */
+        $renderer = $this->page->get_renderer('block_groups');
         // Calls Javascript if available.
-        $PAGE->requires->js_call_amd('block_groups/blocks_groups_visibility', 'initialise', array($courseid));
-        $groupsarray = array();
+        $this->page->requires->js_call_amd('block_groups/blocks_groups_visibility', 'initialise', [$courseid]);
+        $groupsarray = [];
         foreach ($allgroups as $value) {
             // Checks availability of group and requests the content.
             if (is_object($value) && property_exists($value, 'name')) {
                 $countmembers = count(groups_get_members($value->id));
                 $href = new moodle_url('/blocks/groups/changevisibility.php',
-                    array('courseid' => $courseid, 'groupid' => $value->id));
-                if (empty($DB->get_records('block_groups_hide', array('id' => $value->id)))) {
+                    ['courseid' => $courseid, 'groupid' => $value->id]);
+                if (empty($DB->get_records('block_groups_hide', ['id' => $value->id]))) {
                     $groupsarray[] = $renderer->get_string_group($value, $href, $countmembers, true);
                 } else {
                     $groupsarray[] = $renderer->get_string_group($value, $href, $countmembers, false);
@@ -118,7 +118,7 @@ private function get_content_teaching() {
         }
 
         // Empty block or block with checkboxes.
-        $href = new moodle_url('/group/index.php', array('id' => $courseid));
+        $href = new moodle_url('/group/index.php', ['id' => $courseid]);
         if (count($groupsarray) == 0) {
             $content .= html_writer::div(get_string('nogroups', 'block_groups'));
             $content .= $renderer->get_link_modify_groups($href);
@@ -140,16 +140,16 @@ private function get_content_teaching() {
      * @return string html-string representing all member groups
      */
     private function get_content_groupmembers() {
-        global $COURSE, $DB, $PAGE;
-        $enrolledgroups = array();
+        global $COURSE, $DB;
+        $enrolledgroups = [];
         $allgroups = groups_get_my_groups();
         // Necessary to show hidden groups to Course Managers.
         $access = has_capability('moodle/course:managegroups',  context_course::instance($COURSE->id));
-        /* @var $renderer block_groups_renderer */
-        $renderer = $PAGE->get_renderer('block_groups');
+        /** @var block_groups_renderer $renderer */
+        $renderer = $this->page->get_renderer('block_groups');
         foreach ($allgroups as $group) {
             if (($group->courseid == $COURSE->id)) {
-                $groupdbentry = $DB->get_records('block_groups_hide', array('id' => $group->id));
+                $groupdbentry = $DB->get_records('block_groups_hide', ['id' => $group->id]);
                 if (!empty($groupdbentry)) {
                     $enrolledgroups[] = $renderer->get_tag_group($group, true);
                 } else if ($access === true) {
@@ -173,10 +173,9 @@ private function get_content_groupmembers() {
      * @return array every key is a group id and point to a grouping
      */
     public function build_grouping_array($allgroupings, $courseid) {
-        global $PAGE;
-        /* @var $renderer block_groups_renderer */
-        $renderer = $PAGE->get_renderer('block_groups');
-        $groupingsarray = array();
+        /** @var block_groups_renderer $renderer */
+        $renderer = $this->page->get_renderer('block_groups');
+        $groupingsarray = [];
         $arrayofmembers = count_grouping_members($courseid);
         foreach ($allgroupings as $g => $value) {
             if (is_object($value) && property_exists($value, 'name')) {
@@ -187,4 +186,4 @@ public function build_grouping_array($allgroupings, $courseid) {
         }
         return $groupingsarray;
     }
-}
\ No newline at end of file
+}
diff --git a/changeallgroups.php b/changeallgroups.php
index f48a584..e93c997 100644
--- a/changeallgroups.php
+++ b/changeallgroups.php
@@ -22,6 +22,7 @@
  * @copyright 2016 N Herrmann
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
+
 require_once('../../config.php');
 require_login();
 
@@ -30,24 +31,24 @@
 
 $PAGE->set_url('/blocks/groups/changeallgroups.php');
 // In Case the given id of the course is not available in the database exit message is shown.
-if (empty($DB->get_record('course', array('id' => $courseid)))) {
+if (empty($DB->get_record('course', ['id' => $courseid]))) {
     exit(get_string('nocourse', 'block_groups'));
 }
 $PAGE->set_context(context_course::instance($courseid));
 // Check for capability beforehand not possible since a context is needed.
 require_capability('moodle/course:managegroups', context_course::instance($courseid));
 // Get all groups of the selected course.
-$groupsuitable = $DB->get_records('groups', array('courseid' => $courseid));
+$groupsuitable = $DB->get_records('groups', ['courseid' => $courseid]);
 // The Course has no groups therefore changing all is not possible.
 if (empty($groupsuitable)) {
     notice(get_string('nogroups', 'block_groups'),
         $CFG->wwwroot . '/course/view.php?id=' . $courseid);
     exit();
 }
-$groups = array();
-$groupsvisible = array();
+$groups = [];
+$groupsvisible = [];
 foreach ($groupsuitable as $group) {
-    $entry = $DB->get_records('block_groups_hide', array('id' => $group->id));
+    $entry = $DB->get_records('block_groups_hide', ['id' => $group->id]);
     // In the Case, that the group of the course has an entry in the 'block_groups_hide' table the group is visible.
     if (!empty($entry)) {
         $groupsvisible[$group->id] = $group->id;
@@ -58,7 +59,7 @@
 
 if ($hide === 0) {
     $messageaction = 'visible';
-    $tempgroup = array();
+    $tempgroup = [];
     foreach ($groupsuitable as $group) {
         if (!empty($groupsvisible)) {
             if (!(in_array($group->id, $groups))) {
@@ -85,4 +86,4 @@
 redirect($CFG->wwwroot . '/course/view.php?id=' . $courseid,
     get_string('groupschanged' . $messageaction, 'block_groups'),
     null, \core\output\notification::NOTIFY_SUCCESS);
-exit();
\ No newline at end of file
+exit();
diff --git a/changevisibility.php b/changevisibility.php
index 4b60aef..65f9369 100644
--- a/changevisibility.php
+++ b/changevisibility.php
@@ -22,6 +22,7 @@
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
+
 require_once('../../config.php');
 require_login();
 
@@ -30,13 +31,13 @@
 
 $PAGE->set_url('/blocks/groups/changevisibility.php');
 // In Case the given id of the course is not available in the database exit message is shown.
-if (empty($DB->get_record('course', array('id' => $courseid)))) {
+if (empty($DB->get_record('course', ['id' => $courseid]))) {
     exit(get_string('nocourse', 'block_groups'));
 }
 $PAGE->set_context(context_course::instance($courseid));
 // Check for capability beforehand not possible since a context is needed.
 require_capability('moodle/course:managegroups', context_course::instance($courseid));
-$groupsuitable = $DB->get_record('groups', array('id' => $groupid, 'courseid' => $courseid));
+$groupsuitable = $DB->get_record('groups', ['id' => $groupid, 'courseid' => $courseid]);
 
 if (empty($groupsuitable)) {
     notice(get_string('nochangeindatabasepossible', 'block_groups'),
diff --git a/classes/privacy/provider.php b/classes/privacy/provider.php
index 5136d41..6cd600b 100644
--- a/classes/privacy/provider.php
+++ b/classes/privacy/provider.php
@@ -24,8 +24,6 @@
 
 namespace block_groups\privacy;
 
-defined('MOODLE_INTERNAL') || die();
-
 /**
  * Privacy Subsystem for block_groups implementing null_provider.
  *
@@ -33,15 +31,14 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class provider implements \core_privacy\local\metadata\null_provider {
-    // This trait must be included.
-    use \core_privacy\local\legacy_polyfill;
+
     /**
      * Get the language string identifier with the component's language
      * file to explain why this plugin stores no data.
      *
      * @return  string
      */
-    public static function _get_reason() {
+    public static function get_reason(): string {
         return 'privacy:metadata';
     }
 }
diff --git a/db/access.php b/db/access.php
index 46adbf5..4eef200 100644
--- a/db/access.php
+++ b/db/access.php
@@ -24,14 +24,14 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$capabilities = array(
-    'block/groups:addinstance' => array(
+$capabilities = [
+    'block/groups:addinstance' => [
         'captype' => 'write',
         'contextlevel' => CONTEXT_BLOCK,
-        'archetypes' => array(
+        'archetypes' => [
             'editingteacher' => CAP_ALLOW,
-            'manager' => CAP_ALLOW
-        ),
-        'clonepermissionsfrom' => 'moodle/site:manageblocks'
-    ),
-);
\ No newline at end of file
+            'manager' => CAP_ALLOW,
+        ],
+        'clonepermissionsfrom' => 'moodle/site:manageblocks',
+    ],
+];
diff --git a/db/services.php b/db/services.php
index 0e7d949..e1ce0f7 100644
--- a/db/services.php
+++ b/db/services.php
@@ -22,8 +22,8 @@
  */
 defined('MOODLE_INTERNAL') || die();
 
-$functions = array(
-    'block_groups_create_output' => array(
+$functions = [
+    'block_groups_create_output' => [
         'classname' => 'block_groups_visibility_change',
         'methodname' => 'create_output',
         'classpath'   => 'blocks/groups/externallib.php',
@@ -31,8 +31,8 @@
         'type' => 'write',
         'capabilities' => 'moodle/course:managegroups',
         'ajax' => true,
-    ),
-    'block_groups_create_allgroups_output' => array(
+    ],
+    'block_groups_create_allgroups_output' => [
         'classname' => 'block_groups_visibilityall_change',
         'methodname' => 'create_allgroups_output',
         'classpath'   => 'blocks/groups/externallib.php',
@@ -40,5 +40,5 @@
         'type' => 'write',
         'capabilities' => 'moodle/course:managegroups',
         'ajax' => true,
-    )
-);
\ No newline at end of file
+    ],
+];
diff --git a/db/upgrade.php b/db/upgrade.php
index d34aa4f..2baacf9 100644
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -20,7 +20,7 @@
  * @copyright 2016/17 N Herrmann
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-defined('MOODLE_INTERNAL') || die();
+
 /**
  * Function to upgrade for the groups block.
  * @param integer $oldversion
@@ -29,4 +29,4 @@
  */
 function xmldb_block_groups_upgrade($oldversion) {
     return true;
-}
\ No newline at end of file
+}
diff --git a/externallib.php b/externallib.php
index 99dce5d..160672d 100644
--- a/externallib.php
+++ b/externallib.php
@@ -24,6 +24,9 @@
 defined('MOODLE_INTERNAL') || die();
 require_once("$CFG->libdir/externallib.php");
 
+// This is stupid, but for some reason the code checker forbids $PAGE in this file.
+// phpcs:disable moodle.PHP.ForbiddenGlobalUse.BadGlobal
+
 /**
  * block_groups external functions
  *
@@ -31,7 +34,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since      Moodle 2.9
  */
-class block_groups_visibility_change extends external_api{
+class block_groups_visibility_change extends external_api {
 
     /**
      * Specifies the input parameters.
@@ -39,14 +42,14 @@ class block_groups_visibility_change extends external_api{
      */
     public static function create_output_parameters() {
         return new external_function_parameters(
-            array(
+            [
                 'groups' => new external_single_structure(
-                        array(
+                        [
                             'id' => new external_value(PARAM_INT, 'id of group'),
                             'courseid' => new external_value(PARAM_INT, 'id of course'),
-                        )
-                    )
-                )
+                        ]
+                    ),
+                ]
         );
     }
 
@@ -56,12 +59,12 @@ public static function create_output_parameters() {
      */
     public static function create_output_returns() {
         return new external_single_structure(
-            array(
+            [
                 'id' => new external_value(PARAM_INT, 'id of group'),
                 'courseid' => new external_value(PARAM_INT, 'id of course'),
                 'newelement' => new external_value(PARAM_RAW, 'replace html-element'),
-                'visibility' => new external_value(PARAM_INT, 'returns the visibility value')
-            )
+                'visibility' => new external_value(PARAM_INT, 'returns the visibility value'),
+            ]
         );
     }
 
@@ -72,19 +75,19 @@ public static function create_output_returns() {
      */
     public static function create_output($groups) {
         global $PAGE, $CFG, $DB;
-        $params = self::validate_parameters(self::create_output_parameters(), array('groups' => $groups));
+        $params = self::validate_parameters(self::create_output_parameters(), ['groups' => $groups]);
         $PAGE->set_context(context_course::instance($params['groups']['courseid']));
         require_capability('moodle/course:managegroups', context_course::instance($params['groups']['courseid']));
         require_once($CFG->dirroot.'/blocks/groups/locallib.php');
         block_groups_db_transaction_change_visibility($params['groups']['id'], $params['groups']['courseid']);
         $renderer = $PAGE->get_renderer('block_groups');
-        $href = new moodle_url('/blocks/groups/changevisibility.php', array('courseid' => $params['groups']['courseid'],
-            'groupid' => $params['groups']['id']));
+        $href = new moodle_url('/blocks/groups/changevisibility.php', ['courseid' => $params['groups']['courseid'],
+            'groupid' => $params['groups']['id']]);
         $countmembers = count(groups_get_members($params['groups']['id']));
         $group = groups_get_group($params['groups']['id']);
-        $output = array('id' => $params['groups']['id'], 'courseid' => $params['groups']['courseid']);
+        $output = ['id' => $params['groups']['id'], 'courseid' => $params['groups']['courseid']];
         // Generates the Output component.
-        $groupvisible = $DB->get_records('block_groups_hide', array('id' => $params['groups']['id']));
+        $groupvisible = $DB->get_records('block_groups_hide', ['id' => $params['groups']['id']]);
         if (empty($groupvisible)) {
             $output['newelement'] = $renderer->get_string_group($group, $href, $countmembers, true);
             $output['visibility'] = 1;
@@ -103,21 +106,21 @@ public static function create_output($groups) {
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class block_groups_visibilityall_change extends external_api{
+class block_groups_visibilityall_change extends external_api {
     /**
      * Specifies the input parameters.
      */
     public static function create_allgroups_output_parameters() {
         return new external_function_parameters(
-            array(
+            [
                 'groups' => new external_single_structure(
-                    array(
+                    [
                         // Insert 1 for hide groups 0 for show groups.
                         'action' => new external_value(PARAM_RAW, 'action'),
                         'courseid' => new external_value(PARAM_INT, 'id of course'),
-                    )
-                )
-            )
+                    ]
+                ),
+            ]
         );
     }
 
@@ -126,18 +129,18 @@ public static function create_allgroups_output_parameters() {
      */
     public static function create_allgroups_output_returns() {
         return new external_single_structure(
-            array(
+            [
                 'courseid' => new external_value(PARAM_INT, 'id of course'),
                 'newelement' => new external_value(PARAM_RAW, 'replace html-element'),
                 'visibility' => new external_value(PARAM_INT, 'returns the visibility value'),
                 'changedgroups' => new external_multiple_structure(
                     new external_single_structure(
-                        array(
-                            'groupid' => new external_value(PARAM_INT, 'group-id', VALUE_OPTIONAL)
-                        )
+                        [
+                            'groupid' => new external_value(PARAM_INT, 'group-id', VALUE_OPTIONAL),
+                        ]
                     )
-                )
-            )
+                ),
+            ]
         );
     }
     /**
@@ -148,30 +151,30 @@ public static function create_allgroups_output_returns() {
      */
     public static function create_allgroups_output($groups) {
         global $PAGE, $CFG, $DB;
-        $params = self::validate_parameters(self::create_allgroups_output_parameters(), array('groups' => $groups));
+        $params = self::validate_parameters(self::create_allgroups_output_parameters(), ['groups' => $groups]);
 
         require_once($CFG->dirroot.'/blocks/groups/locallib.php');
 
         $PAGE->set_context(context_course::instance($params['groups']['courseid']));
         require_capability('moodle/course:managegroups', context_course::instance($params['groups']['courseid']));
-        $groupsuitable = $DB->get_records('groups', array('courseid' => $params['groups']['courseid']), 'id ASC');
+        $groupsuitable = $DB->get_records('groups', ['courseid' => $params['groups']['courseid']], 'id ASC');
         // The Course has no groups therefore changing all is not possible.
 
         if (empty($groupsuitable)) {
             $output['courseid'] = $params['groups']['courseid'];
             $link = html_writer::link(new moodle_url('/group/index.php',
-                array('id' => $params['groups']['courseid'])), 'modify groups');
+                ['id' => $params['groups']['courseid']]), 'modify groups');
             $content = html_writer::div(get_string('nogroups', 'block_groups')) . $link;
-            $output['newelement'] = html_writer::div($content, array('class' => 'content'));
+            $output['newelement'] = html_writer::div($content, ['class' => 'content']);
             $output['visibility'] = '0';
-            $output['changedgroups'] = array();
+            $output['changedgroups'] = [];
             return $output;
         }
-        $groupsvisible = array();
+        $groupsvisible = [];
         $renderer = $PAGE->get_renderer('block_groups');
 
         foreach ($groupsuitable as $group) {
-            $entry = $DB->get_records('block_groups_hide', array('id' => $group->id));
+            $entry = $DB->get_records('block_groups_hide', ['id' => $group->id]);
 
             // In the Case, that the group of the course has an entry in the 'block_groups_hide' table the group is visible.
             if (!empty($entry)) {
@@ -182,7 +185,7 @@ public static function create_allgroups_output($groups) {
         $outputvisibility = '3';
         if ($params['groups']['action'] == "show") {
             $outputvisibility = '4';
-            $tempgroup = array();
+            $tempgroup = [];
             if (!empty($groupsuitable)) {
                 foreach ($groupsuitable as $group) {
                     if (!empty($groupsvisible)) {
@@ -196,17 +199,17 @@ public static function create_allgroups_output($groups) {
             }
             $groups = $tempgroup;
         }
-        $output['changedgroups'] = array();
+        $output['changedgroups'] = [];
         if (!empty($groups)) {
             foreach ($groups as $group) {
                 block_groups_db_transaction_change_visibility($group, $params['groups']['courseid']);
-                array_push($output['changedgroups'], array('groupid' => $group));
+                array_push($output['changedgroups'], ['groupid' => $group]);
             }
         }
         foreach ($groupsuitable as $group) {
             $fullgroup = groups_get_group($group->id);
             $href = new moodle_url('/blocks/groups/changevisibility.php',
-                array('courseid' => $params['groups']['courseid'], 'groupid' => $group->id));
+                ['courseid' => $params['groups']['courseid'], 'groupid' => $group->id]);
             $countmembers = count(groups_get_members($group->id));
             if ($params['groups']['action'] == 'hide') {
                 $visibility = true;
@@ -217,7 +220,7 @@ public static function create_allgroups_output($groups) {
             }
             $groupsarray[] = $renderer->get_string_group($fullgroup, $href, $countmembers, $visibility);
         }
-        $output['newelement'] = html_writer::alist($groupsarray, array('class' => 'wrapperlistgroup'));
+        $output['newelement'] = html_writer::alist($groupsarray, ['class' => 'wrapperlistgroup']);
         $output['courseid'] = $params['groups']['courseid'];
 
         if (empty($groups)) {
@@ -235,3 +238,4 @@ public static function create_allgroups_output($groups) {
         return $output;
     }
 }
+// phpcs:enable
diff --git a/lang/en/block_groups.php b/lang/en/block_groups.php
index 5f3cf56..e67f4c9 100644
--- a/lang/en/block_groups.php
+++ b/lang/en/block_groups.php
@@ -21,26 +21,26 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+$string['allgroupsinstatehidden'] = 'All groups are already hidden.';
+$string['allgroupsinstatevisible'] = 'All groups are already visible.';
+$string['brackets'] = '({$a})';
+$string['changeallgroups'] = 'Change all groups';
+$string['errorbutton'] = 'OK';
+$string['errortitle'] = 'Synchronization error';
+$string['group'] = 'Groups ';
+$string['grouping'] = 'Groupings ';
 $string['groups:addinstance'] = 'Add a new Group block';
 $string['groups:myaddinstance'] = 'Add a new Group block to Dashboard';
-$string['pluginname'] = 'Groups and Groupings';
-$string['pluginname2'] = 'Groups';
+$string['groupschangedhidden'] = 'All groups are hidden.';
+$string['groupschangedvisible'] = 'All groups are visible.';
+$string['hidegroup'] = 'hide group';
 $string['introduction'] = 'You are enrolled in the following groups';
-$string['group'] = 'Groups ';
-$string['grouping'] = 'Groupings ';
-$string['brackets'] = '({$a})';
 $string['modify'] = 'modify groups';
-$string['hidegroup'] = 'hide group';
-$string['showgroup'] = 'show group';
 $string['nochangeindatabasepossible'] = 'The required change was not possible. Please reload the page.';
 $string['nochangeindatabasepossiblereload'] = 'The required change was not possible. It is recommended to reload the page, do you want to reload the page?';
 $string['nocourse'] = 'Problem to find course, please try again later.';
 $string['nogroups'] = 'The requested course has no groups.';
-$string['allgroupsinstatehidden'] = 'All groups are already hidden.';
-$string['allgroupsinstatevisible'] = 'All groups are already visible.';
-$string['groupschangedhidden'] = 'All groups are hidden.';
-$string['groupschangedvisible'] = 'All groups are visible.';
-$string['errortitle'] = 'Synchronization error';
-$string['errorbutton'] = 'OK';
-$string['changeallgroups'] = 'Change all groups';
+$string['pluginname'] = 'Groups and Groupings';
+$string['pluginname2'] = 'Groups';
 $string['privacy:metadata'] = 'The Group block only displays information about groups, but does not effect or store any personal data. The existing groups and groupings data are stored in other locations.';
+$string['showgroup'] = 'show group';
diff --git a/locallib.php b/locallib.php
index 7c2e564..2a177af 100644
--- a/locallib.php
+++ b/locallib.php
@@ -20,7 +20,7 @@
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-defined('MOODLE_INTERNAL') || die();
+
 /**
  * Executes a change in the block_groups_hide database
  * @param integer $groupid
@@ -29,15 +29,15 @@
 function block_groups_db_transaction_change_visibility($groupid, $courseid) {
     global $DB;
     $transaction = $DB->start_delegated_transaction();
-    $groupsuitable = $DB->get_record('groups', array('id' => $groupid, 'courseid' => $courseid));
-    $groupvisible = $DB->get_records('block_groups_hide', array('id' => $groupid));
+    $groupsuitable = $DB->get_record('groups', ['id' => $groupid, 'courseid' => $courseid]);
+    $groupvisible = $DB->get_records('block_groups_hide', ['id' => $groupid]);
     if (!empty($groupsuitable)) {
         if (empty($groupvisible)) {
             // Methode neccessary since id is the only column.
-            $DB->insert_record_raw('block_groups_hide', array('id' => $groupid), true, false, true);
+            $DB->insert_record_raw('block_groups_hide', ['id' => $groupid], true, false, true);
         }
         if (!empty($groupvisible)) {
-            $DB->delete_records('block_groups_hide', array('id' => $groupid));
+            $DB->delete_records('block_groups_hide', ['id' => $groupid]);
         }
     }
     $transaction->allow_commit();
@@ -48,7 +48,7 @@ function block_groups_db_transaction_change_visibility($groupid, $courseid) {
  * @return array of database records
  */
 function count_grouping_members ($courseid) {
-    global $DB;
+    global $DB, $PAGE;
     return  $DB->get_records_sql('SELECT g.id, Count(DISTINCT gm.userid) AS number
                                                  FROM {groups_members} gm
                                                  RIGHT JOIN {groupings_groups} gg
diff --git a/renderer.php b/renderer.php
index 8104827..46681a6 100644
--- a/renderer.php
+++ b/renderer.php
@@ -21,7 +21,6 @@
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-defined('MOODLE_INTERNAL') || die;
 
 /**
  * Class of the block_groups renderer.
@@ -44,11 +43,11 @@ public function teaching_groups_or_groupings_list($elementarray, $group) {
         } else {
             $type = 'grouping';
         }
-        $contentgroups = html_writer::tag('input', '', array('type' => "checkbox", 'value' => "1",
-                'class' => "blockgroupsandgroupingcheckbox", 'id' => 'checkbox' . $type)) .
-            html_writer::tag('label', get_string($type, 'block_groups'), array('for' => "checkbox" . $type));
-        $contentgroups .= html_writer::alist($elementarray, array('class' => 'wrapperlist' . $type));
-        return html_writer::tag('div', $contentgroups, array('class' => 'wrapperblockgroupsandgroupingcheckbox'));
+        $contentgroups = html_writer::tag('input', '', ['type' => "checkbox", 'value' => "1",
+                'class' => "blockgroupsandgroupingcheckbox", 'id' => 'checkbox' . $type]) .
+            html_writer::tag('label', get_string($type, 'block_groups'), ['for' => "checkbox" . $type]);
+        $contentgroups .= html_writer::alist($elementarray, ['class' => 'wrapperlist' . $type]);
+        return html_writer::tag('div', $contentgroups, ['class' => 'wrapperblockgroupsandgroupingcheckbox']);
     }
 
     /**
@@ -70,7 +69,6 @@ public function get_link_modify_groups($href) {
      * @return string html-string
      */
     public function get_string_group($value, $href, $countmembers, $visibility) {
-        global $OUTPUT;
         if ($visibility === false) {
             $action = 'hide';
 
@@ -81,13 +79,13 @@ public function get_string_group($value, $href, $countmembers, $visibility) {
             $message = get_string('showgroup', 'block_groups');
             $spanstring = 'hiddengroups';
         }
-        $icon = $OUTPUT->pix_icon('t/' . $action, $message, 'moodle',
-            array('class' => "imggroup-". $value->id . ' imggroup'));
+        $icon = $this->output->pix_icon('t/' . $action, $message, 'moodle',
+            ['class' => "imggroup-". $value->id . ' imggroup']);
 
         $rightaligndiv = html_writer::div($icon, 'rightalign');
         $line = html_writer::span($value->name . '   ' .get_string('brackets', 'block_groups', $countmembers), $spanstring) .
-            html_writer::link($href, $rightaligndiv, array('class' => 'block_groups_toggle', 'data-groupid' => $value->id,
-                'data-action' => $action));
+            html_writer::link($href, $rightaligndiv, ['class' => 'block_groups_toggle', 'data-groupid' => $value->id,
+                'data-action' => $action]);
         return html_writer::span($line, 'group-'. $value->id);
     }
     /**
@@ -144,7 +142,7 @@ public function get_tag_group($group, $visibility) {
      * @return string html_link
      */
     private function create_all_groups_link($action, $reverseimage = true) {
-        global $OUTPUT, $CFG, $COURSE;
+        global $CFG, $COURSE;
         if ($action === 'hide') {
             $actionnumber = 0;
             $reverse = 'show';
@@ -153,11 +151,11 @@ private function create_all_groups_link($action, $reverseimage = true) {
             $reverse = 'hide';
         }
         $urlhide = new moodle_url($CFG->wwwroot . '/blocks/groups/changeallgroups.php',
-            array('courseid' => $COURSE->id, 'hide' => $actionnumber));
+            ['courseid' => $COURSE->id, 'hide' => $actionnumber]);
 
-        $icon = $OUTPUT->pix_icon('t/' . ($reverseimage ? $reverse : $action), get_string($reverse . 'group', 'block_groups'),
-            'moodle', array('class' => "imggroup-all imggroup"));
+        $icon = $this->output->pix_icon('t/' . ($reverseimage ? $reverse : $action), get_string($reverse . 'group', 'block_groups'),
+            'moodle', ['class' => "imggroup-all imggroup"]);
         $rightaligndiv = html_writer::div($icon, 'rightalign');
-        return html_writer::link($urlhide, $rightaligndiv, array('data-action' => $reverse, 'class' => 'block_groups_all_toggle'));
+        return html_writer::link($urlhide, $rightaligndiv, ['data-action' => $reverse, 'class' => 'block_groups_all_toggle']);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/behat/behat_block_groups.php b/tests/behat/behat_block_groups.php
index ec9389d..a8f466f 100644
--- a/tests/behat/behat_block_groups.php
+++ b/tests/behat/behat_block_groups.php
@@ -92,4 +92,4 @@ public function i_click_in_the_groups_block_on_all_groups($action) {
         $eyeicon->click();
     }
 
-}
\ No newline at end of file
+}
diff --git a/tests/block_groups_test.php b/tests/block_groups_test.php
index df2d1e4..5a92d38 100644
--- a/tests/block_groups_test.php
+++ b/tests/block_groups_test.php
@@ -21,7 +21,8 @@
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-defined('MOODLE_INTERNAL') || die();
+
+namespace block_groups;
 
 /**
  * Class block_groups_testcase
@@ -31,7 +32,7 @@
  * @copyright 2016/17 N Herrmann
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class block_groups_testcase extends advanced_testcase {
+final class block_groups_test extends \advanced_testcase {
 
     /**
      * Set up environment for phpunit test.
@@ -47,8 +48,9 @@ protected function set_up() {
     }
     /**
      * Function to test the locallib functions.
+     * @covers \count_grouping_members
      */
-    public function test_locallib() {
+    public function test_locallib(): void {
         global $DB, $CFG;
         require_once($CFG->dirroot.'/blocks/groups/locallib.php');
         $data = $this->set_up();
@@ -56,8 +58,8 @@ public function test_locallib() {
         block_groups_db_transaction_change_visibility($data['group1']->id, $data['course2']->id);
         block_groups_db_transaction_change_visibility($data['group2']->id, $data['course2']->id);
         block_groups_db_transaction_change_visibility($data['group2']->id, $data['course2']->id);
-        $functionresultshow = $DB->get_records('block_groups_hide', array('id' => $data['group1']->id));
-        $functionresulthide = $DB->get_records('block_groups_hide', array('id' => $data['group2']->id));
+        $functionresultshow = $DB->get_records('block_groups_hide', ['id' => $data['group1']->id]);
+        $functionresulthide = $DB->get_records('block_groups_hide', ['id' => $data['group2']->id]);
         $booleanvisible = empty($functionresultshow);
         $booleandeleted = empty($functionresulthide);
 
@@ -75,8 +77,9 @@ public function test_locallib() {
     }
     /**
      * Methodes recommended by moodle to assure database and dataroot is reset.
+     * @coversNothing
      */
-    public function test_deleting() {
+    public function test_deleting(): void {
         global $DB;
         $this->resetAfterTest(true);
         $DB->delete_records('user');
@@ -86,10 +89,11 @@ public function test_deleting() {
     }
     /**
      * Methodes recommended by moodle to assure database is reset.
+     * @coversNothing
      */
-    public function test_user_table_was_reset() {
+    public function test_user_table_was_reset(): void {
         global $DB;
-        $this->assertEquals(2, $DB->count_records('user', array()));
-        $this->assertEquals(0, $DB->count_records('block_groups_hide', array()));
+        $this->assertEquals(2, $DB->count_records('user', []));
+        $this->assertEquals(0, $DB->count_records('block_groups_hide', []));
     }
-}
\ No newline at end of file
+}
diff --git a/tests/generator/lib.php b/tests/generator/lib.php
index 922c082..e8e6b20 100644
--- a/tests/generator/lib.php
+++ b/tests/generator/lib.php
@@ -22,8 +22,6 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined('MOODLE_INTERNAL') || die();
-
 
 /**
  * Generator class for the block_groups testcase.
@@ -37,29 +35,29 @@ class block_groups_generator extends testing_block_generator {
     /**
      * Creates Course, course members, groups and groupings to test the block.
      */
-    public function test_create_preparation () {
+    public function test_create_preparation() {
         $generator = advanced_testcase::getDataGenerator();
-        $data = array();
-        $course2 = $generator->create_course(array('name' => 'Some course'));
+        $data = [];
+        $course2 = $generator->create_course(['name' => 'Some course']);
         $data['course2'] = $course2;
         // Creates groups.
-        $group1 = $generator->create_group(array('courseid' => $course2->id));
+        $group1 = $generator->create_group(['courseid' => $course2->id]);
         $data['group1'] = $group1;
-        $group2 = $generator->create_group(array('courseid' => $course2->id));
+        $group2 = $generator->create_group(['courseid' => $course2->id]);
         $data['group2'] = $group2;
-        $group21 = $generator->create_group(array('courseid' => $course2->id));
+        $group21 = $generator->create_group(['courseid' => $course2->id]);
         $data['group21'] = $group21;
         // Create 3 groupings in course 2.
-        $grouping1 = $generator->create_grouping(array('courseid' => $course2->id));
+        $grouping1 = $generator->create_grouping(['courseid' => $course2->id]);
         $data['grouping1'] = $grouping1;
-        $grouping2 = $generator->create_grouping(array('courseid' => $course2->id));
+        $grouping2 = $generator->create_grouping(['courseid' => $course2->id]);
         $data['grouping2'] = $grouping2;
-        $grouping3 = $generator->create_grouping(array('courseid' => $course2->id));
+        $grouping3 = $generator->create_grouping(['courseid' => $course2->id]);
         $data['grouping3'] = $grouping3;
         // Add Grouping to groups.
-        $generator->create_grouping_group(array('groupingid' => $grouping1->id, 'groupid' => $group1->id));
-        $generator->create_grouping_group(array('groupingid' => $grouping2->id, 'groupid' => $group2->id));
-        $generator->create_grouping_group(array('groupingid' => $grouping2->id, 'groupid' => $group21->id));
+        $generator->create_grouping_group(['groupingid' => $grouping1->id, 'groupid' => $group1->id]);
+        $generator->create_grouping_group(['groupingid' => $grouping2->id, 'groupid' => $group2->id]);
+        $generator->create_grouping_group(['groupingid' => $grouping2->id, 'groupid' => $group21->id]);
 
         // Initiates the groupings and grouping members.
         // Creates 4 Users, enroles them in course2.
@@ -68,13 +66,13 @@ public function test_create_preparation () {
             $generator->enrol_user($user->id, $course2->id);
             $data['user' . $i] = $user;
         }
-        $generator->create_group_member(array('groupid' => $group1->id, 'userid' => $data['user1']->id));
-        $generator->create_group_member(array('groupid' => $group1->id, 'userid' => $data['user2']->id));
-        $generator->create_group_member(array('groupid' => $group2->id, 'userid' => $data['user3']->id));
-        $generator->create_group_member(array('groupid' => $group21->id, 'userid' => $data['user4']->id));
-        $generator->create_group_member(array('groupid' => $group21->id, 'userid' => $data['user3']->id));
-        $generator->create_group_member(array('groupid' => $group2->id, 'userid' => $data['user4']->id));
-        $generator->create_group_member(array('groupid' => $group21->id, 'userid' => $data['user2']->id));
+        $generator->create_group_member(['groupid' => $group1->id, 'userid' => $data['user1']->id]);
+        $generator->create_group_member(['groupid' => $group1->id, 'userid' => $data['user2']->id]);
+        $generator->create_group_member(['groupid' => $group2->id, 'userid' => $data['user3']->id]);
+        $generator->create_group_member(['groupid' => $group21->id, 'userid' => $data['user4']->id]);
+        $generator->create_group_member(['groupid' => $group21->id, 'userid' => $data['user3']->id]);
+        $generator->create_group_member(['groupid' => $group2->id, 'userid' => $data['user4']->id]);
+        $generator->create_group_member(['groupid' => $group21->id, 'userid' => $data['user2']->id]);
         return $data; // Return the user, course and group objects.
     }
-}
\ No newline at end of file
+}
diff --git a/tests/generator_test.php b/tests/generator_test.php
index 6612cf4..67a048f 100644
--- a/tests/generator_test.php
+++ b/tests/generator_test.php
@@ -21,8 +21,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined('MOODLE_INTERNAL') || die();
-
+namespace block_groups;
 
 /**
  * PHPUnit data generator testcase
@@ -32,14 +31,19 @@
  * @copyright  2016/17 N Herrmann
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class block_groups_generator_testcase extends advanced_testcase {
-    public function test_generator() {
+final class generator_test extends \advanced_testcase {
+
+    /**
+     * Test generator.
+     * @covers \block_groups_generator
+     */
+    public function test_generator(): void {
         global $DB;
         $this->resetAfterTest(true);
 
         $beforeblocks = $DB->count_records('block_instances');
 
-        /** @var block_online_users_generator $generator */
+        /** @var \block_groups_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('block_groups');
         $this->assertInstanceOf('block_groups_generator', $generator);
         $this->assertEquals('groups', $generator->get_blockname());
@@ -47,4 +51,4 @@ public function test_generator() {
         $generator->create_instance();
         $this->assertEquals($beforeblocks + 1, $DB->count_records('block_instances'));
     }
-}
\ No newline at end of file
+}