diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d646a17..2669a5b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,3 +9,4 @@ jobs:
     with:
       disable_behat: true
       disable_phpcpd: true
+      extra_plugin_runners: 'moodle-plugin-ci add-plugin --branch MOODLE_404_STABLE catalyst/moodle-tool_dynamic_cohorts'
diff --git a/classes/helper.php b/classes/helper.php
new file mode 100644
index 0000000..adbb414
--- /dev/null
+++ b/classes/helper.php
@@ -0,0 +1,265 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+namespace tool_enrolprofile;
+
+use context_system;
+use stdClass;
+use tool_dynamic_cohorts\cohort_manager;
+use tool_dynamic_cohorts\condition_base;
+use tool_dynamic_cohorts\rule;
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once($CFG->dirroot . '/cohort/lib.php');
+
+/**
+ * Helper class.
+ *
+ * @package     tool_enrolprofile
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
+ * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class helper {
+
+    /**
+     * Tag item type.
+     */
+    public const ITEM_TYPE_TAG = 'tag';
+
+    /**
+     * Category item type.
+     */
+    public const ITEM_TYPE_CATEGORY = 'category';
+
+    /**
+     * Course item type.
+     */
+    public const ITEM_TYPE_COURSE = 'course';
+
+    /**
+     * Field shortname
+     */
+    public const FIELD_ENROLLED_UNTIL = 'enrolleduntil';
+
+    /**
+     * Course field name.
+     */
+    public const COURSE_NAME = 'fullname';
+
+    /**
+     * Field shortname
+     */
+    public const COHORT_FIELD_ID = 'id';
+
+    /**
+     * Field shortname
+     */
+    public const COHORT_FIELD_TYPE = 'type';
+
+    /**
+     * Role shortname.
+     */
+    public const STUDENT_ROLE = 'student';
+
+    /**
+     * Set up configuration item.
+     *
+     * @param int $itemid Item ID number
+     * @param string $itemtype Item type (tag, course, category).
+     * @param string $itemname Item name.
+     * @param stdClass|null $course Course to set up enrolment method. If not set, the no enrolment method will be created.
+     * @return void
+     */
+    public static function set_up_item(int $itemid, string $itemtype, string $itemname, ?stdClass $course = null): void {
+        $cohort = self::get_cohort_by_item($itemid, $itemtype);
+
+        if (empty($cohort)) {
+            $cohort = new stdClass();
+            $cohort->contextid = context_system::instance()->id;
+            $cohort->name = $itemname;
+            $cohort->idnumber = $itemname;
+            $cohort->description = ucfirst($itemtype) . ' related';
+            $typefieled = 'customfield_' . self::COHORT_FIELD_TYPE;
+            $cohort->$typefieled = $itemtype;
+            $idfieled = 'customfield_' . self::COHORT_FIELD_ID;
+            $cohort->$idfieled = $itemid;
+
+            // Create a new cohort.
+            $cohort->id = self::add_cohort($cohort);
+        }
+
+        // Create a dynamic cohort rule associated with this cohort.
+        self::add_rule($cohort, $itemtype);
+        // Add a tag to a custom profile field.
+        self::update_profile_field($itemtype, $itemname);
+
+        // Create enrolment method for the cohort for a given course.
+        if (!empty($course)) {
+            self::add_enrolment_method($course, $cohort);
+        }
+    }
+
+    /**
+     * Get cohort by provided item type and item id.
+     *
+     * @param int $itemid Item ID.
+     * @param string $itemtype Item type.
+     *
+     * @return stdClass|null
+     */
+    public static function get_cohort_by_item(int $itemid, string $itemtype): ?stdClass {
+        $systemcontext = context_system::instance();
+
+        $allcohorts = cohort_get_cohorts($systemcontext->id, 0, 0, '', true);
+        // Load custom fields data and filter bby custom field type and id.
+        $cohorts = array_filter($allcohorts['cohorts'], function ($cohortdata) use ($itemid, $itemtype) {
+            foreach ($cohortdata->customfields as $customfield) {
+                $name = 'customfield_' . $customfield->get_field()->get('shortname');
+                $cohortdata->$name = $customfield->export_value();
+            }
+            $typefieled = 'customfield_' . self::COHORT_FIELD_TYPE;
+            $idfieled = 'customfield_' . self::COHORT_FIELD_ID;
+
+            return $cohortdata->$typefieled == $itemtype && $cohortdata->$idfieled == $itemid;
+        });
+
+        if (!empty($cohorts)) {
+            return reset($cohorts);
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Helper method to add enrolment method to a course.
+     *
+     * @param stdClass $course Course.
+     * @param stdClass $cohort Cohort.
+     *
+     * @return void
+     */
+    public static function add_enrolment_method(stdClass $course, stdClass $cohort): void {
+        global $DB;
+
+        $studentrole = $DB->get_record('role', ['shortname' => self::STUDENT_ROLE]);
+
+        $fields = [
+            'customint1' => $cohort->id,
+            'roleid' => $studentrole->id,
+            'courseid' => $course->id,
+        ];
+
+        if (!$DB->record_exists('enrol', $fields)) {
+            $enrol = enrol_get_plugin('cohort');
+            $enrol->add_instance($course, $fields);
+        }
+    }
+
+    /**
+     * Update profile field with new item.
+     *
+     * @param string $shortname Field short name.
+     * @param string $newitem A new item to add to the field.
+     *
+     * @return void
+     */
+    public static function update_profile_field(string $shortname, string $newitem): void {
+        global $DB;
+
+        $field = $DB->get_record('user_info_field', ['shortname' => $shortname]);
+        $fielddata = [];
+        if (!empty($field->param1)) {
+            $fielddata = explode("\n", $field->param1);
+        }
+
+        if (!in_array($newitem, $fielddata)) {
+            $fielddata[] = $newitem;
+            sort($fielddata);
+            $field->param1 = implode("\n", $fielddata);
+            $DB->update_record('user_info_field', $field);
+        }
+    }
+
+    /**
+     * Add cohort.
+     *
+     * @param stdClass $cohort Cohort.
+     *
+     * @return int
+     */
+    public static function add_cohort(stdClass $cohort): int {
+        global $DB;
+        if (!$existingcohort = $DB->get_record('cohort', ['name' => $cohort->name])) {
+            return cohort_add_cohort($cohort);
+        } else {
+            return $existingcohort->id;
+        }
+    }
+
+    /**
+     * A helper method to set up rule for given cohort.
+     *
+     * @param stdClass $cohort Cohort.
+     * @param string $fieldshortname Related profile field shortname.
+     *
+     * @return void
+     */
+    public static function add_rule(stdClass $cohort, string $fieldshortname): void {
+        if (rule::get_record(['cohortid' => $cohort->id])) {
+            return;
+        }
+
+        cohort_manager::manage_cohort($cohort->id);
+        $rule = new rule(0, (object)[
+            'name' => $cohort->name,
+            'cohortid' => $cohort->id,
+            'description' => $cohort->description,
+        ]);
+        $rule->save();
+
+        $condition = condition_base::get_instance(0, (object)[
+            'classname' => 'tool_dynamic_cohorts\local\tool_dynamic_cohorts\condition\user_custom_profile',
+        ]);
+
+        $fieldname = 'profile_field_' . $fieldshortname;
+        $condition->set_config_data([
+            'profilefield' => $fieldname,
+            $fieldname . '_operator' => condition_base::TEXT_IS_EQUAL_TO,
+            $fieldname . '_value' => $cohort->name,
+        ]);
+        $condition->get_record()->set('ruleid', $rule->get('id'));
+        $condition->get_record()->set('sortorder', 0);
+        $condition->get_record()->save();
+
+        $condition = condition_base::get_instance(0, (object)[
+            'classname' => 'tool_dynamic_cohorts\local\tool_dynamic_cohorts\condition\user_custom_profile',
+        ]);
+
+        $fieldname = 'profile_field_' . self::FIELD_ENROLLED_UNTIL;
+        $condition->set_config_data([
+            'profilefield' => $fieldname,
+            $fieldname . '_operator' => condition_base::DATE_IN_THE_FUTURE,
+            $fieldname . '_value' => 0,
+        ]);
+        $condition->get_record()->set('ruleid', $rule->get('id'));
+        $condition->get_record()->set('sortorder', 0);
+        $condition->get_record()->save();
+
+        $rule->set('enabled', 1);
+        $rule->save();
+    }
+}
diff --git a/classes/observer.php b/classes/observer.php
new file mode 100644
index 0000000..094795b
--- /dev/null
+++ b/classes/observer.php
@@ -0,0 +1,77 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+namespace tool_enrolprofile;
+
+use core\event\course_category_created;
+use core\event\course_created;
+use core\event\tag_added;
+
+/**
+ * Event observer class.
+ *
+ * @package     tool_enrolprofile
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
+ * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class observer {
+
+    /**
+     * Process tag_added event.
+     *
+     * @param tag_added $event The event.
+     */
+    public static function tag_added(tag_added $event): void {
+        // Check context is course context.
+        $context = $event->get_context();
+        if ($context->contextlevel != CONTEXT_COURSE && $event->other['itemtype'] != 'course') {
+            return;
+        }
+
+        $tagid = $event->other['tagid'];
+        $tagname = $event->other['tagrawname'];
+        $course = get_course($event->other['itemid']);
+
+        helper::set_up_item($tagid, helper::ITEM_TYPE_TAG, $tagname, $course);
+    }
+
+    /**
+     * Process course_created event.
+     *
+     * @param course_created $event The event.
+     */
+    public static function course_created(course_created $event): void {
+        global $DB;
+
+        $course = get_course($event->courseid);
+        helper::set_up_item($course->id, helper::ITEM_TYPE_COURSE, $course->{helper::COURSE_NAME}, $course);
+
+        $category = $DB->get_record('course_categories', ['id' => $course->category]);
+        helper::set_up_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name, $course);
+    }
+
+    /**
+     * Process course_category_created event.
+     *
+     * @param course_category_created $event The event.
+     */
+    public static function course_category_created(course_category_created $event): void {
+        global $DB;
+
+        $category = $DB->get_record('course_categories', ['id' => $event->objectid]);
+        helper::set_up_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name);
+    }
+}
diff --git a/db/events.php b/db/events.php
new file mode 100644
index 0000000..8d5dd1e
--- /dev/null
+++ b/db/events.php
@@ -0,0 +1,40 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+/**
+ * Plugin event observers are registered here.
+ *
+ * @package     tool_enrolprofile
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
+ * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+$observers = [
+    [
+        'eventname' => '\core\event\tag_added',
+        'callback' => '\tool_enrolprofile\observer::tag_added',
+    ],
+    [
+        'eventname' => '\core\event\course_created',
+        'callback' => '\tool_enrolprofile\observer::course_created',
+    ],
+    [
+        'eventname' => '\core\event\course_category_created',
+        'callback' => '\tool_enrolprofile\observer::course_category_created',
+    ],
+];
diff --git a/lang/en/tool_enrolprofile.php b/lang/en/tool_enrolprofile.php
index ab312c1..1d5fe01 100644
--- a/lang/en/tool_enrolprofile.php
+++ b/lang/en/tool_enrolprofile.php
@@ -19,7 +19,7 @@
  *
  * @package     tool_enrolprofile
  * @category    string
- * @copyright   2024 Your Name <you@example.com>
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
  * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
diff --git a/tests/helper_test.php b/tests/helper_test.php
new file mode 100644
index 0000000..ac51a76
--- /dev/null
+++ b/tests/helper_test.php
@@ -0,0 +1,91 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+namespace tool_enrolprofile;
+
+use advanced_testcase;
+use core_customfield\field_controller;
+
+/**
+ * Unit tests for helper class.
+ *
+ * @package     tool_enrolprofile
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
+ * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ *
+ * @covers     \tool_enrolprofile\observer
+ */
+class helper_test extends advanced_testcase {
+
+    /**
+     * Create cohort custom field for testing.
+     *
+     * @param string $shortname Field shortname
+     * @param string $datatype $field data type.
+     *
+     * @return field_controller
+     */
+    protected function create_cohort_custom_field(string $shortname, string $datatype = 'text'): field_controller {
+        $fieldcategory = self::getDataGenerator()->create_custom_field_category([
+            'component' => 'core_cohort',
+            'area' => 'cohort',
+            'name' => 'Other fields',
+        ]);
+
+        return self::getDataGenerator()->create_custom_field([
+            'shortname' => $shortname,
+            'name' => 'Custom field ' . $shortname,
+            'type' => $datatype,
+            'categoryid' => $fieldcategory->get('id'),
+        ]);
+    }
+
+    /**
+     * Test getting a cohort by item id.
+     */
+    public function test_get_cohort_by_item(): void {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        $this->create_cohort_custom_field(helper::COHORT_FIELD_ID);
+        $this->create_cohort_custom_field(helper::COHORT_FIELD_TYPE);
+
+        $typefieled = 'customfield_' . helper::COHORT_FIELD_TYPE;
+        $idfieled = 'customfield_' . helper::COHORT_FIELD_ID;
+
+        $cohort1 = self::getDataGenerator()->create_cohort([
+            $typefieled => 'tag',
+            $idfieled => 12,
+        ]);
+
+        $cohort2 = self::getDataGenerator()->create_cohort([
+            $typefieled => 'tag',
+            $idfieled => 13,
+        ]);
+
+        $cohort3 = self::getDataGenerator()->create_cohort([
+            $typefieled => 'course',
+            $idfieled => 13,
+        ]);
+
+        $this->assertNull(helper::get_cohort_by_item(1, 'tag'));
+        $this->assertNull(helper::get_cohort_by_item(1, 'course'));
+
+        $this->assertEquals($cohort1->id, helper::get_cohort_by_item(12, 'tag')->id);
+        $this->assertEquals($cohort2->id, helper::get_cohort_by_item(13, 'tag')->id);
+        $this->assertEquals($cohort3->id, helper::get_cohort_by_item(13, 'course')->id);
+    }
+}
diff --git a/tests/observer_test.php b/tests/observer_test.php
new file mode 100644
index 0000000..ee5e586
--- /dev/null
+++ b/tests/observer_test.php
@@ -0,0 +1,289 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+namespace tool_enrolprofile;
+
+use advanced_testcase;
+use core_customfield\field_controller;
+use core_tag_tag;
+use context_course;
+
+/**
+ * Unit tests for observer class.
+ *
+ * @package     tool_enrolprofile
+ * @copyright   2024 Dmitrii Metelkin <dnmetelk@gmail.comt>
+ * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ *
+ * @covers     \tool_enrolprofile\observer
+ */
+class observer_test extends advanced_testcase {
+
+    /**
+     * Tag profile field for testing.
+     * @var \stdClass
+     */
+    protected $tagprofilefield;
+
+    /**
+     * Course profile field for testing.
+     * @var \stdClass
+     */
+    protected $courseprofilefield;
+
+    /**
+     * Category profile field for testing.
+     * @var \stdClass
+     */
+    protected $categoryprofilefield;
+
+    /**
+     * Set up before every test.
+     *
+     * @return void
+     */
+    public function setUp(): void {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        $this->tagprofilefield = $this->add_user_profile_field(helper::ITEM_TYPE_TAG, 'autocomplete');
+        $this->courseprofilefield = $this->add_user_profile_field(helper::ITEM_TYPE_COURSE, 'autocomplete');
+        $this->categoryprofilefield = $this->add_user_profile_field(helper::ITEM_TYPE_CATEGORY, 'autocomplete');
+
+        $this->create_cohort_custom_field(helper::COHORT_FIELD_ID);
+        $this->create_cohort_custom_field(helper::COHORT_FIELD_TYPE);
+    }
+
+    /**
+     * A helper function to create a custom profile field.
+     *
+     * @param string $shortname Short name of the field.
+     * @param string $datatype Type of the field, e.g. text, checkbox, datetime, menu and etc.
+     * @param array $extras A list of extra fields for the field (e.g. forceunique, param1 and etc)
+     *
+     * @return \stdClass
+     */
+    protected function add_user_profile_field(string $shortname, string $datatype, array $extras = []): \stdClass {
+        global $DB;
+
+        $data = new \stdClass();
+        $data->shortname = $shortname;
+        $data->datatype = $datatype;
+        $data->name = 'Test ' . $shortname;
+        $data->description = 'This is a test field';
+        $data->required = false;
+        $data->locked = false;
+        $data->forceunique = false;
+        $data->signup = false;
+        $data->visible = '0';
+        $data->categoryid = '0';
+
+        foreach ($extras as $name => $value) {
+            $data->{$name} = $value;
+        }
+
+        $data->id = $DB->insert_record('user_info_field', $data);
+
+        return $data;
+    }
+
+    /**
+     * Create cohort custom field for testing.
+     *
+     * @param string $shortname Field shortname
+     * @param string $datatype $field data type.
+     *
+     * @return field_controller
+     */
+    protected function create_cohort_custom_field(string $shortname, string $datatype = 'text'): field_controller {
+        $fieldcategory = self::getDataGenerator()->create_custom_field_category([
+            'component' => 'core_cohort',
+            'area' => 'cohort',
+            'name' => 'Other fields',
+        ]);
+
+        return self::getDataGenerator()->create_custom_field([
+            'shortname' => $shortname,
+            'name' => 'Custom field ' . $shortname,
+            'type' => $datatype,
+            'categoryid' => $fieldcategory->get('id'),
+        ]);
+    }
+
+    /**
+     * Check logic when adding a tag.
+     */
+    public function test_tag_added(): void {
+        global $DB;
+
+        $course = $this->getDataGenerator()->create_course();
+        $tagname = 'A tag';
+
+        $this->assertEmpty($DB->get_record('cohort', ['name' => $tagname]));
+        $this->assertEmpty($DB->get_field('user_info_field', 'param1', ['id' => $this->tagprofilefield->id]));
+        $this->assertEmpty($DB->get_record('tag', ['rawname' => $tagname]));
+        $this->assertEmpty($DB->get_record('tool_dynamic_cohorts', ['name' => $tagname]));
+
+        // Should be already course and category cohorts.
+        $this->assertCount(2, $DB->get_records('enrol', ['courseid' => $course->id, 'enrol' => 'cohort']));
+
+        core_tag_tag::set_item_tags('core', 'course', $course->id, context_course::instance($course->id), [$tagname]);
+
+        $tag = $DB->get_record('tag', ['rawname' => $tagname]);
+        $this->assertNotEmpty($tag);
+
+        $cohort = $DB->get_record('cohort', ['name' => $tagname]);
+        $this->assertNotEmpty($cohort);
+
+        $cohort = cohort_get_cohort($cohort->id, context_course::instance($course->id), true);
+        foreach ($cohort->customfields as $customfield) {
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_ID) {
+                $this->assertSame($tag->id, $customfield->export_value());
+            }
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_TYPE) {
+                $this->assertSame(helper::ITEM_TYPE_TAG, $customfield->export_value());
+            }
+        }
+
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->tagprofilefield->id]);
+        $this->assertNotEmpty($profilefielddata);
+        $this->assertTrue(in_array($tagname, explode("\n", $profilefielddata)));
+
+        $rule = $DB->get_record('tool_dynamic_cohorts', ['name' => $tagname]);
+        $this->assertNotEmpty($rule);
+        $this->assertEquals($cohort->id, $rule->cohortid);
+        $this->assertEquals(1, $rule->enabled);
+        $conditions = $DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]);
+        $this->assertCount(2, $conditions);
+
+        $this->assertCount(3, $DB->get_records('enrol', ['courseid' => $course->id, 'enrol' => 'cohort']));
+        $enrol = $DB->get_record('enrol', ['courseid' => $course->id, 'enrol' => 'cohort', 'customint1' => $cohort->id]);
+        $this->assertNotEmpty($enrol);
+    }
+
+    /**
+     * Check logic when creating a course.
+     */
+    public function test_course_created(): void {
+        global $DB;
+
+        $coursename = 'Course name';
+        $this->assertEmpty($DB->get_record('cohort', ['name' => $coursename]));
+        $this->assertEmpty($DB->get_field('user_info_field', 'param1', ['id' => $this->courseprofilefield->id]));
+        $this->assertEmpty($DB->get_record('tool_dynamic_cohorts', ['name' => $coursename]));
+
+        $course = $this->getDataGenerator()->create_course(['fullname' => $coursename]);
+
+        // Should be course and category cohorts.
+        $this->assertCount(2, $DB->get_records('enrol', ['courseid' => $course->id, 'enrol' => 'cohort']));
+
+        // Check everything about course cohort.
+        $coursecohort = $DB->get_record('cohort', ['name' => $coursename]);
+        $this->assertNotEmpty($coursecohort);
+
+        $cohort = cohort_get_cohort($coursecohort->id, context_course::instance($course->id), true);
+        foreach ($cohort->customfields as $customfield) {
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_ID) {
+                $this->assertSame($course->id, $customfield->export_value());
+            }
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_TYPE) {
+                $this->assertSame(helper::ITEM_TYPE_COURSE, $customfield->export_value());
+            }
+        }
+
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->courseprofilefield->id]);
+        $this->assertNotEmpty($profilefielddata);
+        $this->assertTrue(in_array($coursename, explode("\n", $profilefielddata)));
+
+        $rule = $DB->get_record('tool_dynamic_cohorts', ['name' => $coursename]);
+        $this->assertNotEmpty($rule);
+        $this->assertEquals($cohort->id, $rule->cohortid);
+        $this->assertEquals(1, $rule->enabled);
+        $conditions = $DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]);
+        $this->assertCount(2, $conditions);
+
+        $enrol = $DB->get_record('enrol', ['courseid' => $course->id, 'enrol' => 'cohort', 'customint1' => $cohort->id]);
+        $this->assertNotEmpty($enrol);
+
+        // Check everything about category cohort.
+        $category = $DB->get_record('course_categories', ['id' => $course->category]);
+        $categorycohort = $DB->get_record('cohort', ['name' => $category->name]);
+        $this->assertNotEmpty($categorycohort);
+
+        $cohort = cohort_get_cohort($categorycohort->id, context_course::instance($category->id), true);
+        foreach ($cohort->customfields as $customfield) {
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_ID) {
+                $this->assertSame($category->id, $customfield->export_value());
+            }
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_TYPE) {
+                $this->assertSame(helper::ITEM_TYPE_CATEGORY, $customfield->export_value());
+            }
+        }
+
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->categoryprofilefield->id]);
+        $this->assertNotEmpty($profilefielddata);
+        $this->assertTrue(in_array($category->name, explode("\n", $profilefielddata)));
+
+        $rule = $DB->get_record('tool_dynamic_cohorts', ['name' => $category->name]);
+        $this->assertNotEmpty($rule);
+        $this->assertEquals($cohort->id, $rule->cohortid);
+        $this->assertEquals(1, $rule->enabled);
+        $conditions = $DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]);
+        $this->assertCount(2, $conditions);
+
+        $enrol = $DB->get_record('enrol', ['courseid' => $course->id, 'enrol' => 'cohort', 'customint1' => $cohort->id]);
+        $this->assertNotEmpty($enrol);
+    }
+
+    /**
+     * Check logic when creating a course category.
+     */
+    public function test_course_category_created(): void {
+        global $DB;
+
+        $categoryname = 'Category name';
+        $this->assertEmpty($DB->get_record('cohort', ['name' => $categoryname]));
+        $this->assertEmpty($DB->get_field('user_info_field', 'param1', ['id' => $this->categoryprofilefield->id]));
+        $this->assertEmpty($DB->get_record('tool_dynamic_cohorts', ['name' => $categoryname]));
+
+        $category = $this->getDataGenerator()->create_category(['name' => $categoryname]);
+
+        // Check everything about category cohort.
+        $categorycohort = $DB->get_record('cohort', ['name' => $category->name]);
+        $this->assertNotEmpty($categorycohort);
+
+        $cohort = cohort_get_cohort($categorycohort->id, \context_coursecat::instance($category->id), true);
+        foreach ($cohort->customfields as $customfield) {
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_ID) {
+                $this->assertSame($category->id, $customfield->export_value());
+            }
+            if ($customfield->get_field()->get('shortname') == helper::COHORT_FIELD_TYPE) {
+                $this->assertSame(helper::ITEM_TYPE_CATEGORY, $customfield->export_value());
+            }
+        }
+
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->categoryprofilefield->id]);
+        $this->assertNotEmpty($profilefielddata);
+        $this->assertTrue(in_array($categoryname, explode("\n", $profilefielddata)));
+
+        $rule = $DB->get_record('tool_dynamic_cohorts', ['name' => $categoryname]);
+        $this->assertNotEmpty($rule);
+        $this->assertEquals($cohort->id, $rule->cohortid);
+        $this->assertEquals(1, $rule->enabled);
+        $conditions = $DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]);
+        $this->assertCount(2, $conditions);
+    }
+}