diff --git a/tests/advanced_passcode_test.php b/tests/advanced_passcode_test.php
index 0f71df62..77549162 100644
--- a/tests/advanced_passcode_test.php
+++ b/tests/advanced_passcode_test.php
@@ -65,7 +65,7 @@ public static function setUpBeforeClass(): void {
      * Tests that a default password of 6 numbers is created when settings are null.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_default() {
+    public function test_settings_default(): void {
         $this->zoomdata = (object) webservice::DEFAULT_MEETING_PASSWORD_REQUIREMENT;
 
         $passcode = zoom_create_default_passcode($this->zoomdata);
@@ -77,7 +77,7 @@ public function test_settings_default() {
      * Tests that a password has the given minimum length.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_length() {
+    public function test_settings_length(): void {
         $data = [
             'length' => 8,
             'have_letter' => false,
@@ -95,7 +95,7 @@ public function test_settings_length() {
      * Tests that a password is all numbers when the setting is specified.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_only_numeric() {
+    public function test_settings_only_numeric(): void {
         $data = [
             'length' => 10,
             'have_letter' => false,
@@ -114,7 +114,7 @@ public function test_settings_only_numeric() {
      * Tests that a password has a letter when the setting is specified.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_letter() {
+    public function test_settings_letter(): void {
         $data = [
             'length' => null,
             'have_letter' => true,
@@ -133,7 +133,7 @@ public function test_settings_letter() {
      * Tests that a password has uppercase and lowercase letters when the setting is specified.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_upper_and_lower_letters() {
+    public function test_settings_upper_and_lower_letters(): void {
         $data = [
             'length' => null,
             'have_letter' => true,
@@ -153,7 +153,7 @@ public function test_settings_upper_and_lower_letters() {
      * Tests that a password has a special character when the setting is specified.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_special_character() {
+    public function test_settings_special_character(): void {
         $data = [
             'length' => null,
             'have_letter' => null,
@@ -172,7 +172,7 @@ public function test_settings_special_character() {
      * Tests that a password has correct length, a letter, and a special character when setting is specified.
      * @covers ::zoom_create_default_passcode
      */
-    public function test_settings_all() {
+    public function test_settings_all(): void {
         $data = [
             'length' => 7,
             'have_letter' => true,
@@ -192,7 +192,7 @@ public function test_settings_all() {
      * Tests that the password description is correct when all settings are present.
      * @covers ::zoom_create_passcode_description
      */
-    public function test_pasword_description_all() {
+    public function test_pasword_description_all(): void {
         $data = [
             'length' => 9,
             'have_letter' => true,
@@ -215,7 +215,7 @@ public function test_pasword_description_all() {
      * Tests that the password description is correct when the only numeric option is present.
      * @covers ::zoom_create_passcode_description
      */
-    public function test_pasword_description_only_numeric() {
+    public function test_pasword_description_only_numeric(): void {
         $data = [
             'length' => 8,
             'have_letter' => false,
@@ -237,7 +237,7 @@ public function test_pasword_description_only_numeric() {
      * Tests that the password description is correct when the default settings are present.
      * @covers ::zoom_create_passcode_description
      */
-    public function test_pasword_description_default() {
+    public function test_pasword_description_default(): void {
         $this->zoomdata = (object) webservice::DEFAULT_MEETING_PASSWORD_REQUIREMENT;
 
         $description = zoom_create_passcode_description($this->zoomdata);
diff --git a/tests/error_handling_test.php b/tests/error_handling_test.php
index 78e4f46e..51446625 100644
--- a/tests/error_handling_test.php
+++ b/tests/error_handling_test.php
@@ -79,7 +79,7 @@ public function setUp(): void {
      * @covers ::zoom_is_meeting_gone_error
      * @covers ::zoom_is_user_not_found_error
      */
-    public function test_correct_error_recognition() {
+    public function test_correct_error_recognition(): void {
         // Check meeting not found behavior.
         $this->assertTrue(zoom_is_meeting_gone_error($this->meetingnotfoundexception));
         $this->assertTrue(zoom_is_meeting_gone_error($this->usernotfoundexception));
diff --git a/tests/get_meeting_reports_test.php b/tests/get_meeting_reports_test.php
index 09b264d9..06d02208 100644
--- a/tests/get_meeting_reports_test.php
+++ b/tests/get_meeting_reports_test.php
@@ -85,7 +85,7 @@ public function setUp(): void {
     /**
      * Make sure that format_participant() filters bad data from Zoom.
      */
-    public function test_format_participant_filtering() {
+    public function test_format_participant_filtering(): void {
         // Sometimes Zoom has a # instead of comma in the name.
         $this->zoomdata->name = 'SMITH# JOE';
         $participant = $this->meetingtask->format_participant($this->zoomdata, 1, [], []);
@@ -95,7 +95,7 @@ public function test_format_participant_filtering() {
     /**
      * Make sure that format_participant() can match Moodle users.
      */
-    public function test_format_participant_matching() {
+    public function test_format_participant_matching(): void {
         global $DB;
         return;
 
@@ -186,7 +186,7 @@ public function test_format_participant_matching() {
      * Make sure that format_participant() can match Moodle users more
      * aggressively on name.
      */
-    public function test_format_participant_name_matching() {
+    public function test_format_participant_name_matching(): void {
         // Enroll a bunch of users. Note: names were generated by
         // https://www.behindthename.com/random/ and any similarity to anyone
         // real or ficitional is concidence and not intentional.
@@ -252,7 +252,7 @@ public function test_format_participant_name_matching() {
      * Tests that we can handle when the Zoom API sometimes returns invalid
      * userids in the report/meeting/participants call.
      */
-    public function test_invalid_userids() {
+    public function test_invalid_userids(): void {
         global $DB, $SITE;
 
         // Make sure we start with nothing.
@@ -342,7 +342,7 @@ public function test_invalid_userids() {
      * Tests that normalize_meeting() can handle different meeting records from
      * Dashboard API versus the Report API.
      */
-    public function test_normalize_meeting() {
+    public function test_normalize_meeting(): void {
         $dashboardmeeting = [
             'uuid' => 'sfsdfsdfc6122222d',
             'id' => 1000000,
diff --git a/tests/mod_zoom_grade_test.php b/tests/mod_zoom_grade_test.php
index f8a8e1cd..22fade56 100644
--- a/tests/mod_zoom_grade_test.php
+++ b/tests/mod_zoom_grade_test.php
@@ -76,7 +76,7 @@ public function setUp(): void {
      * Tests that Zoom grades can be added and updated in the gradebook.
      * @covers ::zoom_grade_item_update
      */
-    public function test_grade_added() {
+    public function test_grade_added(): void {
         $params['course'] = $this->course->id;
         $params['grade'] = 100;
 
@@ -109,7 +109,7 @@ public function test_grade_added() {
      * Tests that the Zoom grade type cannot be changed to NONE if grades are already inputted.
      * @covers ::zoom_grade_item_update
      */
-    public function test_grade_type_not_none() {
+    public function test_grade_type_not_none(): void {
         $params['course'] = $this->course->id;
         $params['grade'] = 100;
 
@@ -140,7 +140,7 @@ public function test_grade_type_not_none() {
      * Tests that the Zoom grades can be deleted.
      * @covers ::zoom_grade_item_delete
      */
-    public function test_grade_delete() {
+    public function test_grade_delete(): void {
         $params['course'] = $this->course->id;
         $params['grade'] = 100;
 
diff --git a/tests/mod_zoom_invitation_test.php b/tests/mod_zoom_invitation_test.php
index 3a6aa0b7..477e3482 100644
--- a/tests/mod_zoom_invitation_test.php
+++ b/tests/mod_zoom_invitation_test.php
@@ -53,7 +53,7 @@ protected function setUp(): void {
     /**
      * Test zoom invitation display message for user with all capabilities.
      */
-    public function test_display_message_when_user_has_all_capabilities() {
+    public function test_display_message_when_user_has_all_capabilities(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         $course = $this->getDataGenerator()->create_course();
@@ -112,7 +112,7 @@ public function test_display_message_when_user_has_all_capabilities() {
     /**
      * Test zoom invitation display message for user with only the mod/zoom:viewjoinurl capability.
      */
-    public function test_display_message_when_user_has_viewjoinurl_capability() {
+    public function test_display_message_when_user_has_viewjoinurl_capability(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         $user = $this->getDataGenerator()->create_user();
@@ -140,7 +140,7 @@ public function test_display_message_when_user_has_viewjoinurl_capability() {
     /**
      * Test zoom invitation display message for user with only the mod/zoom:viewdialin capability.
      */
-    public function test_display_message_when_user_has_viewdialin_capability() {
+    public function test_display_message_when_user_has_viewdialin_capability(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         $user = $this->getDataGenerator()->create_user();
@@ -197,7 +197,7 @@ public function test_display_message_when_user_has_viewdialin_capability() {
     /**
      * Test zoom invitation display message for user has no capabilities.
      */
-    public function test_display_message_when_user_has_no_capabilities() {
+    public function test_display_message_when_user_has_no_capabilities(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         $user = $this->getDataGenerator()->create_user();
@@ -218,7 +218,7 @@ public function test_display_message_when_user_has_no_capabilities() {
     /**
      * Test message if regex pattern is intentionally set to empty for an element.
      */
-    public function test_display_message_when_a_regex_pattern_is_empty() {
+    public function test_display_message_when_a_regex_pattern_is_empty(): void {
         global $PAGE;
         $this->resetAfterTest();
         $this->setAdminUser();
@@ -239,7 +239,7 @@ public function test_display_message_when_a_regex_pattern_is_empty() {
     /**
      * Test debug message if regex pattern is not valid for an element.
      */
-    public function test_display_message_when_a_regex_pattern_is_invalid() {
+    public function test_display_message_when_a_regex_pattern_is_invalid(): void {
         global $PAGE;
         $this->resetAfterTest();
         $this->setAdminUser();
@@ -260,7 +260,7 @@ public function test_display_message_when_a_regex_pattern_is_invalid() {
     /**
      * Test debug message if no match is found using regex pattern for an element.
      */
-    public function test_display_message_when_a_regex_pattern_is_finds_no_match() {
+    public function test_display_message_when_a_regex_pattern_is_finds_no_match(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         set_config('invitation_joinurl', '/nomatch/mi', 'zoom');
@@ -278,7 +278,7 @@ public function test_display_message_when_a_regex_pattern_is_finds_no_match() {
     /**
      * Test removing the invite sentence from the zoom meeting message.
      */
-    public function test_display_message_has_invite_removed_if_setting_enabled() {
+    public function test_display_message_has_invite_removed_if_setting_enabled(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         set_config('invitationremoveinvite', '1', 'zoom');
@@ -336,7 +336,7 @@ public function test_display_message_has_invite_removed_if_setting_enabled() {
     /**
      * Test not removing the invite sentence from the zoom meeting message.
      */
-    public function test_display_message_does_not_have_invite_removed_if_setting_disabled() {
+    public function test_display_message_does_not_have_invite_removed_if_setting_disabled(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         set_config('invitationremoveinvite', '0', 'zoom');
@@ -396,7 +396,7 @@ public function test_display_message_does_not_have_invite_removed_if_setting_dis
     /**
      * Test removing the iCal link from the zoom meeting message.
      */
-    public function test_display_message_has_icallink_removed_if_setting_enabled() {
+    public function test_display_message_has_icallink_removed_if_setting_enabled(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         set_config('invitationremoveicallink', '1', 'zoom');
@@ -569,7 +569,7 @@ public function test_display_message_has_icallink_removed_if_setting_enabled() {
     /**
      * Test not removing the iCal link from the zoom meeting message.
      */
-    public function test_display_message_does_not_have_icallink_removed_if_setting_disabled() {
+    public function test_display_message_does_not_have_icallink_removed_if_setting_disabled(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         set_config('invitationremoveicallink', '0', 'zoom');
@@ -738,7 +738,7 @@ public function test_display_message_does_not_have_icallink_removed_if_setting_d
     /**
      * Test get_display_string returns null without throwing an error if the invitation string provided is null.
      */
-    public function test_display_message_when_instantiated_with_null_zoom_meeting_invitation() {
+    public function test_display_message_when_instantiated_with_null_zoom_meeting_invitation(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
         $course = $this->getDataGenerator()->create_course();
@@ -750,7 +750,7 @@ public function test_display_message_when_instantiated_with_null_zoom_meeting_in
     /**
      * Test display message is returned in full regardless of capabilities if regex patterns are disabled.
      */
-    public function test_display_message_when_user_has_no_capabilities_with_regex_disabled() {
+    public function test_display_message_when_user_has_no_capabilities_with_regex_disabled(): void {
         set_config('invitationregexenabled', 0, 'zoom');
         $this->resetAfterTest();
         $this->setAdminUser();
diff --git a/tests/mod_zoom_webservice_test.php b/tests/mod_zoom_webservice_test.php
index 3b687503..1f551931 100644
--- a/tests/mod_zoom_webservice_test.php
+++ b/tests/mod_zoom_webservice_test.php
@@ -85,7 +85,7 @@ public function get_info() {
     /**
      * Tests that uuid are encoded properly for use in web service calls.
      */
-    public function test_encode_uuid() {
+    public function test_encode_uuid(): void {
         $service = zoom_webservice();
 
         // If uuid includes / or // it needs to be double encoded.
@@ -103,7 +103,7 @@ public function test_encode_uuid() {
     /**
      * Tests whether the meeting not found errors are properly parsed.
      */
-    public function test_meeting_not_found_exception() {
+    public function test_meeting_not_found_exception(): void {
         $mockservice = $this->getMockBuilder('\mod_zoom\webservice')
             ->setMethods(['make_curl_call', 'get_curl_object', 'get_access_token'])
             ->getMock();
@@ -135,7 +135,7 @@ public function test_meeting_not_found_exception() {
     /**
      * Tests whether user not found errors are properly parsed.
      */
-    public function test_user_not_found_exception() {
+    public function test_user_not_found_exception(): void {
         $mockservice = $this->getMockBuilder('\mod_zoom\webservice')
             ->setMethods(['make_curl_call', 'get_curl_object', 'get_access_token'])
             ->getMock();
@@ -168,7 +168,7 @@ public function test_user_not_found_exception() {
     /**
      * Tests whether invalid user errors are parsed properly
      */
-    public function test_invalid_user_exception() {
+    public function test_invalid_user_exception(): void {
         $invalidmockcurl = new class {
             // @codingStandardsIgnoreStart
             /**
@@ -229,7 +229,7 @@ public function get_info() {
      * Tests whether the retry on a 429 works properly when the Retry-After header
      * is in the curl response to specify the time that the retry should be sent.
      */
-    public function test_retry_with_header() {
+    public function test_retry_with_header(): void {
         $retrywithheadermockcurl = new class {
             public $numgetinfocalls = 0;
             // @codingStandardsIgnoreStart
@@ -308,7 +308,7 @@ public function getResponse() {
      * Tests whether the retry on a 429 response works when the Retry-After
      * header is not sent in the curl response.
      */
-    public function test_retry_without_header() {
+    public function test_retry_without_header(): void {
         $retrynoheadermockcurl = new class {
             public $numgetinfocalls = 0;
             // @codingStandardsIgnoreStart
@@ -376,7 +376,7 @@ public function getResponse() {
     /**
      * Tests that we throw error if we tried more than max retries.
      */
-    public function test_retry_exception() {
+    public function test_retry_exception(): void {
         $retryfailuremockcurl = new class {
             public $urlpath = null;
             // @codingStandardsIgnoreStart
@@ -463,7 +463,7 @@ public function getResponse() {
     /**
      * Tests that we are waiting 1 minute for QPS rate limit types.
      */
-    public function test_retryqps_exception() {
+    public function test_retryqps_exception(): void {
         $retryqpsmockcurl = new class {
             public $urlpath = null;
             // @codingStandardsIgnoreStart
diff --git a/tests/privacy/mod_zoom_provider_test.php b/tests/privacy/mod_zoom_provider_test.php
index f643611a..08d79dd7 100644
--- a/tests/privacy/mod_zoom_provider_test.php
+++ b/tests/privacy/mod_zoom_provider_test.php
@@ -146,7 +146,7 @@ protected function setUp(): void {
      * Test for provider::get_metadata().
      * @covers ::get_metadata
      */
-    public function test_get_metadata() {
+    public function test_get_metadata(): void {
         $collection = new collection('mod_zoom');
         $newcollection = provider::get_metadata($collection);
         $itemcollection = $newcollection->get_collection();
@@ -190,7 +190,7 @@ public function test_get_metadata() {
      * Test for provider::get_contexts_for_userid().
      * @covers ::get_contexts_for_userid
      */
-    public function test_get_contexts_for_userid() {
+    public function test_get_contexts_for_userid(): void {
         $contextlist = provider::get_contexts_for_userid($this->student->id);
         $this->assertCount(1, $contextlist);
         $contextforuser = $contextlist->current();
@@ -208,7 +208,7 @@ public function test_get_contexts_for_userid() {
      * Test for provider::get_users_in_context().
      * @covers ::get_users_in_context
      */
-    public function test_get_users_in_context() {
+    public function test_get_users_in_context(): void {
         $cmcontext = context_module::instance($this->cm->id);
 
         $userlist = new userlist($cmcontext, 'mod_zoom');
@@ -221,7 +221,7 @@ public function test_get_users_in_context() {
      * Test for provider::export_user_data().
      * @covers ::export_user_data
      */
-    public function test_export_user_data() {
+    public function test_export_user_data(): void {
         $cmcontext = context_module::instance($this->cm->id);
 
         // Export all of the data for the context.
@@ -234,7 +234,7 @@ public function test_export_user_data() {
      * Test for provider::delete_data_for_all_users_in_context().
      * @covers ::delete_data_for_all_users_in_context
      */
-    public function test_delete_data_for_all_users_in_context() {
+    public function test_delete_data_for_all_users_in_context(): void {
         global $DB;
 
         $zoommeetingcount = $DB->count_records('zoom_meeting_details');
@@ -270,7 +270,7 @@ public function test_delete_data_for_all_users_in_context() {
      * Test for provider::delete_data_for_user().
      * @covers ::delete_data_for_user
      */
-    public function test_delete_data_for_user() {
+    public function test_delete_data_for_user(): void {
         global $DB;
 
         $zmparticipants = $DB->count_records('zoom_meeting_participants');
@@ -295,7 +295,7 @@ public function test_delete_data_for_user() {
      * Test for provider::delete_data_for_users().
      * @covers ::delete_data_for_users
      */
-    public function test_delete_data_for_users() {
+    public function test_delete_data_for_users(): void {
         global $DB;
 
         $zmparticipants = $DB->count_records('zoom_meeting_participants');