diff --git a/completion/tests/coverage.php b/completion/tests/coverage.php
new file mode 100644
index 00000000000..2a758a79d66
--- /dev/null
+++ b/completion/tests/coverage.php
@@ -0,0 +1,47 @@
+<?php
+// This file is part of Moodle - http://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 <http://www.gnu.org/licenses/>.
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Coverage information for the core_completion.
+ *
+ * @package    core
+ * @category   phpunit
+ * @copyright  2022 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+/**
+ * Coverage information for the core subsystem.
+ *
+ * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+return new class extends phpunit_coverage_info {
+    /** @var array The list of folders relative to the plugin root to include in coverage generation. */
+    protected $includelistfolders = [
+        'criteria',
+    ];
+
+    /** @var array The list of files relative to the plugin root to include in coverage generation. */
+    protected $includelistfiles = [
+        'completion_aggregation.php',
+        'completion_completion.php',
+        'completion_criteria_completion.php',
+        'data_object.php'
+    ];
+};
diff --git a/lib/tests/completionlib_test.php b/lib/tests/completionlib_test.php
index e35f5be614f..b393c90dbe8 100644
--- a/lib/tests/completionlib_test.php
+++ b/lib/tests/completionlib_test.php
@@ -29,7 +29,17 @@ defined('MOODLE_INTERNAL') || die();
 global $CFG;
 require_once($CFG->libdir.'/completionlib.php');
 
-class core_completionlib_testcase extends advanced_testcase {
+/**
+ * Completion tests.
+ *
+ * @package    core_completion
+ * @category   phpunit
+ * @copyright  2008 Sam Marshall
+ * @copyright  2013 Frédéric Massart
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @coversDefaultClass \completion_info
+ */
+class completionlib_test extends advanced_testcase {
     protected $course;
     protected $user;
     protected $module1;
@@ -90,6 +100,10 @@ class core_completionlib_testcase extends advanced_testcase {
         parent::assertEquals($expected, $actual, $message, $delta, $maxDepth, $canonicalize, $ignoreCase);
     }
 
+    /**
+     * @covers ::is_enabled_for_site
+     * @covers ::is_enabled
+     */
     public function test_is_enabled() {
         global $CFG;
         $this->mock_setup();
@@ -125,6 +139,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEquals(COMPLETION_TRACKING_AUTOMATIC, $c->is_enabled($cm));
     }
 
+    /**
+     * @covers ::update_state
+     */
     public function test_update_state() {
         $this->mock_setup();
 
@@ -348,6 +365,7 @@ class core_completionlib_testcase extends advanced_testcase {
      * @param int $completionusegrade
      * @param string $unsetfield
      * @param int $expectedstate
+     * @covers ::internal_get_state
      */
     public function test_internal_get_state(int $completionview, int $completionusegrade, string $unsetfield, int $expectedstate) {
         $this->setup_data();
@@ -379,6 +397,7 @@ class core_completionlib_testcase extends advanced_testcase {
      * Provider for the test_internal_get_state_with_grade_criteria.
      *
      * @return array
+     * @covers ::internal_get_state
      */
     public function test_internal_get_state_with_grade_criteria_provider() {
         return [
@@ -432,6 +451,7 @@ class core_completionlib_testcase extends advanced_testcase {
      * @param array $completioncriteria The completion criteria to use
      * @param int|null $studentgrade Grade to assign to student
      * @param int $expectedstate Expected completion state
+     * @covers ::internal_get_state
      */
     public function test_internal_get_state_with_grade_criteria(array $completioncriteria, ?int $studentgrade, int $expectedstate) {
         $this->setup_data();
@@ -472,6 +492,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Covers the case where internal_get_state() is being called for a user different from the logged in user.
+     *
+     * @covers ::internal_get_state
      */
     public function test_internal_get_state_with_different_user() {
         $this->setup_data();
@@ -514,6 +536,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for internal_get_state() for an activity that supports custom completion.
+     *
+     * @covers ::internal_get_state
      */
     public function test_internal_get_state_with_custom_completion() {
         $this->setup_data();
@@ -540,6 +564,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEquals(COMPLETION_COMPLETE, $completion);
     }
 
+    /**
+     * @covers ::set_module_viewed
+     */
     public function test_set_module_viewed() {
         $this->mock_setup();
 
@@ -595,6 +622,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $c->set_module_viewed($cm, 1337);
     }
 
+    /**
+     * @covers ::count_user_data
+     */
     public function test_count_user_data() {
         global $DB;
         $this->mock_setup();
@@ -611,6 +641,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEquals(666, $c->count_user_data($cm));
     }
 
+    /**
+     * @covers ::delete_all_state
+     */
     public function test_delete_all_state() {
         global $DB;
         $this->mock_setup();
@@ -628,6 +661,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $c->delete_all_state($cm);
     }
 
+    /**
+     * @covers ::reset_all_state
+     */
     public function test_reset_all_state() {
         global $DB;
         $this->mock_setup();
@@ -703,6 +739,7 @@ class core_completionlib_testcase extends advanced_testcase {
      * @param bool $sameuser Whether the user calling get_data() is the user itself.
      * @param bool $hasrecord Whether to create a course_modules_completion record.
      * @param int $completion The completion state expected.
+     * @covers ::get_data
      */
     public function test_get_data(bool $wholecourse, bool $sameuser, bool $hasrecord, int $completion) {
         global $DB;
@@ -769,6 +806,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Tests for completion_info::get_other_cm_completion_data().
+     *
+     * @covers ::get_other_cm_completion_data
      */
     public function test_get_other_cm_completion_data() {
         global $DB;
@@ -842,6 +881,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEmpty($choice2completiondata);
     }
 
+    /**
+     * @covers ::internal_set_data
+     */
     public function test_internal_set_data() {
         global $DB;
         $this->setup_data();
@@ -938,6 +980,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEquals($this->user->id, reset($actual)->userid);
     }
 
+    /**
+     * @covers ::get_progress_all
+     */
     public function test_get_progress_all_few() {
         global $DB;
         $this->mock_setup();
@@ -972,6 +1017,9 @@ class core_completionlib_testcase extends advanced_testcase {
             ), $c->get_progress_all(false));
     }
 
+    /**
+     * @covers ::get_progress_all
+     */
     public function test_get_progress_all_lots() {
         global $DB;
         $this->mock_setup();
@@ -1027,6 +1075,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertCount(count($tracked), $result);
     }
 
+    /**
+     * @covers ::inform_grade_changed
+     */
     public function test_inform_grade_changed() {
         $this->mock_setup();
 
@@ -1095,6 +1146,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $c->inform_grade_changed($cm, $item, $grade, true);
     }
 
+    /**
+     * @covers ::internal_get_grade_state
+     */
     public function test_internal_get_grade_state() {
         $this->mock_setup();
 
@@ -1137,6 +1191,9 @@ class core_completionlib_testcase extends advanced_testcase {
             completion_info::internal_get_grade_state($item, $grade));
     }
 
+    /**
+     * @test ::get_activities
+     */
     public function test_get_activities() {
         global $CFG;
         $this->resetAfterTest();
@@ -1178,6 +1235,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertFalse(isset($activities[$data2->cmid]));
     }
 
+    /**
+     * @test ::has_activities
+     */
     public function test_has_activities() {
         global $CFG;
         $this->resetAfterTest();
@@ -1203,7 +1263,8 @@ class core_completionlib_testcase extends advanced_testcase {
     /**
      * Test that data is cleaned up when we delete courses that are set as completion criteria for other courses
      *
-     * @return void
+     * @covers ::delete_course_completion_data
+     * @covers ::delete_all_completion_data
      */
     public function test_course_delete_prerequisite() {
         global $DB;
@@ -1240,6 +1301,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test course module completion update event.
+     *
+     * @covers \core\event\course_module_completion_updated
      */
     public function test_course_module_completion_updated_event() {
         global $USER, $CFG;
@@ -1277,6 +1340,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test course completed event.
+     *
+     * @covers \core\event\course_completed
      */
     public function test_course_completed_event() {
         global $USER;
@@ -1306,6 +1371,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test course completed message.
+     *
+     * @covers \core\event\course_completed
      */
     public function test_course_completed_message() {
         $this->setup_data();
@@ -1332,6 +1399,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test course completed event.
+     *
+     * @covers \core\event\course_completion_updated
      */
     public function test_course_completion_updated_event() {
         $this->setup_data();
@@ -1358,6 +1427,9 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertEventLegacyLogData($expectedlegacylog, $event);
     }
 
+    /**
+     * @covers \completion_can_view_data
+     */
     public function test_completion_can_view_data() {
         $this->setup_data();
 
@@ -1393,6 +1465,7 @@ class core_completionlib_testcase extends advanced_testcase {
      * @param int|null $passinggrade Passing grade to set for the test activity.
      * @param string|null $expectedexception Expected exception.
      * @param int|null $expectedresult The expected completion status.
+     * @covers ::get_grade_completion
      */
     public function test_get_grade_completion(bool $completionusegrade, bool $hasgrade, ?int $passinggrade,
         ?string $expectedexception, ?int $expectedresult) {
@@ -1425,6 +1498,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test the return value for cases when the activity module does not have associated grade_item.
+     *
+     * @covers ::get_grade_completion
      */
     public function test_get_grade_completion_without_grade_item() {
         global $DB;
@@ -1463,6 +1538,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for aggregate_completions().
+     *
+     * @covers \aggregate_completions
      */
     public function test_aggregate_completions() {
         global $DB;
@@ -1557,6 +1634,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for completion_completion::_save().
+     *
+     * @covers \completion_completion::_save
      */
     public function test_save() {
         global $DB;
@@ -1601,6 +1680,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for completion_completion::mark_enrolled().
+     *
+     * @covers \completion_completion::mark_enrolled
      */
     public function test_mark_enrolled() {
         global $DB;
@@ -1642,6 +1723,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for completion_completion::mark_inprogress().
+     *
+     * @covers \completion_completion::mark_inprogress
      */
     public function test_mark_inprogress() {
         global $DB;
@@ -1683,6 +1766,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for completion_completion::mark_complete().
+     *
+     * @covers \completion_completion::mark_complete
      */
     public function test_mark_complete() {
         global $DB;
@@ -1723,6 +1808,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
     /**
      * Test for completion_criteria_completion::mark_complete().
+     *
+     * @covers \completion_criteria_completion::mark_complete
      */
     public function test_criteria_mark_complete() {
         global $DB;