diff --git a/admin/tool/behat/tests/manager_util_test.php b/admin/tool/behat/tests/manager_util_test.php
index 71b4b94575a..50563c4dc98 100644
--- a/admin/tool/behat/tests/manager_util_test.php
+++ b/admin/tool/behat/tests/manager_util_test.php
@@ -149,7 +149,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_single_run() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
 
@@ -188,7 +188,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_single_run_no_theme() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
 
@@ -242,7 +242,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_parallel_run() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
 
@@ -345,7 +345,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_parallel_run_optimize_tags() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
 
@@ -489,7 +489,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_blacklisted_tags() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_blacklisted_tests_for_theme',
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_blacklisted_tests_for_theme',
             'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
@@ -553,7 +553,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_get_config_file_contents_with_blacklisted_features_contexts() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_blacklisted_tests_for_theme',
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_blacklisted_tests_for_theme',
             'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
@@ -632,7 +632,7 @@ class tool_behat_manager_util_testcase extends advanced_testcase {
     public function test_core_features_to_include_in_specified_theme() {
 
         $mockbuilder = $this->getMockBuilder('behat_config_util');
-        $mockbuilder->setMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
+        $mockbuilder->onlyMethods(array('get_theme_test_directory', 'get_list_of_themes', 'get_default_theme', 'get_theme_config'));
 
         $behatconfigutil = $mockbuilder->getMock();
 
diff --git a/admin/tool/dataprivacy/tests/expired_contexts_test.php b/admin/tool/dataprivacy/tests/expired_contexts_test.php
index 6a47ae41f88..863cb827e56 100644
--- a/admin/tool/dataprivacy/tests/expired_contexts_test.php
+++ b/admin/tool/dataprivacy/tests/expired_contexts_test.php
@@ -857,7 +857,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_users_in_context',
                 'delete_data_for_all_users_in_context',
@@ -868,7 +868,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
 
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -935,7 +935,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_users_in_context',
                 'delete_data_for_all_users_in_context',
@@ -956,7 +956,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             }));
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
 
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -1023,7 +1023,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_users_in_context',
                 'delete_data_for_all_users_in_context',
@@ -1044,7 +1044,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             }));
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
 
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -1112,7 +1112,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_users_in_context',
                 'delete_data_for_all_users_in_context',
@@ -1133,7 +1133,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             }));
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
 
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -1208,7 +1208,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_users_in_context',
                 'delete_data_for_all_users_in_context',
@@ -1229,7 +1229,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             }));
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
 
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -1260,7 +1260,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1269,7 +1269,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1299,7 +1299,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1308,7 +1308,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1335,7 +1335,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1344,7 +1344,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1382,7 +1382,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1396,7 +1396,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             );
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1442,7 +1442,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1451,7 +1451,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->once())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1494,7 +1494,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $this->setUser();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1503,7 +1503,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1546,7 +1546,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         set_config('siteadmins', implode(',', $admins));
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1555,7 +1555,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1600,7 +1600,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredblockcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1614,7 +1614,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             );
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1653,7 +1653,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredusercontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1667,7 +1667,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             );
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1705,7 +1705,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1714,7 +1714,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
         $manager->method('get_privacy_manager')->willReturn($mockprivacymanager);
@@ -1756,7 +1756,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1765,7 +1765,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1814,7 +1814,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredforumcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1823,7 +1823,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $mockprivacymanager->expects($this->never())->method('delete_data_for_all_users_in_context');
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
@@ -1872,7 +1872,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
         $expiredforumcontext->save();
 
         $mockprivacymanager = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods([
+            ->onlyMethods([
                 'delete_data_for_user',
                 'delete_data_for_all_users_in_context',
             ])
@@ -1886,7 +1886,7 @@ class tool_dataprivacy_expired_contexts_testcase extends advanced_testcase {
             );
 
         $manager = $this->getMockBuilder(\tool_dataprivacy\expired_contexts_manager::class)
-            ->setMethods(['get_privacy_manager'])
+            ->onlyMethods(['get_privacy_manager'])
             ->getMock();
         $manager->set_progress(new \null_progress_trace());
 
diff --git a/admin/tool/dataprivacy/tests/filtered_userlist_test.php b/admin/tool/dataprivacy/tests/filtered_userlist_test.php
index cdffded9be2..d9c4b249608 100644
--- a/admin/tool/dataprivacy/tests/filtered_userlist_test.php
+++ b/admin/tool/dataprivacy/tests/filtered_userlist_test.php
@@ -42,7 +42,7 @@ class tool_dataprivacy_filtered_userlist_testcase extends advanced_testcase {
     public function test_apply_expired_contexts_filters(array $initial, array $expired, array $unexpired, array $expected) {
         $userlist = $this->getMockBuilder(\tool_dataprivacy\filtered_userlist::class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
 
         $rc = new \ReflectionClass(\tool_dataprivacy\filtered_userlist::class);
diff --git a/admin/tool/langimport/tests/locale_test.php b/admin/tool/langimport/tests/locale_test.php
index 4d1ffef94aa..7b6380c0887 100644
--- a/admin/tool/langimport/tests/locale_test.php
+++ b/admin/tool/langimport/tests/locale_test.php
@@ -42,7 +42,7 @@ class locale_testcase extends \advanced_testcase {
         // - second setlocale() call which try to set new 'es' locale
         // - third setlocale() call which restore locale.
         $mock = $this->getMockBuilder(\tool_langimport\locale::class)
-            ->setMethods(['set_locale'])
+            ->onlyMethods(['set_locale'])
             ->getMock();
         $mock->method('set_locale')->will($this->onConsecutiveCalls('en', 'es', 'en'));
 
@@ -55,7 +55,7 @@ class locale_testcase extends \advanced_testcase {
         // - second setlocale() call which fail to set new locale
         // - third setlocale() call which restore locale.
         $mock = $this->getMockBuilder(\tool_langimport\locale::class)
-            ->setMethods(['set_locale'])
+            ->onlyMethods(['set_locale'])
             ->getMock();
         $mock->method('set_locale')->will($this->onConsecutiveCalls('en', false, 'en'));
 
diff --git a/admin/tool/monitor/tests/subscription_test.php b/admin/tool/monitor/tests/subscription_test.php
index 364b1c43849..3a71907c696 100644
--- a/admin/tool/monitor/tests/subscription_test.php
+++ b/admin/tool/monitor/tests/subscription_test.php
@@ -43,7 +43,7 @@ class tool_monitor_subscription_testcase extends advanced_testcase {
         $sub->name = 'My test rule';
         $sub->courseid = 20;
         $mockbuilder = $this->getMockBuilder('\tool_monitor\subscription');
-        $mockbuilder->setMethods(null);
+        $mockbuilder->onlyMethods([]);
         $mockbuilder->setConstructorArgs(array($sub));
         $this->subscription = $mockbuilder->getMock();
     }
diff --git a/admin/tool/usertours/tests/step_test.php b/admin/tool/usertours/tests/step_test.php
index fb6a3c1d85f..70538b289a0 100644
--- a/admin/tool/usertours/tests/step_test.php
+++ b/admin/tool/usertours/tests/step_test.php
@@ -117,7 +117,7 @@ class step_testcase extends advanced_testcase {
      */
     public function test_fetch() {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods(['reload_from_record'])
+            ->onlyMethods(['reload_from_record'])
             ->getMock()
             ;
 
@@ -185,7 +185,7 @@ class step_testcase extends advanced_testcase {
      */
     public function test_is_first_step($sortorder, $count, $isfirst, $islast) {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods(['get_sortorder'])
+            ->onlyMethods(['get_sortorder'])
             ->getMock();
 
         $step->expects($this->once())
@@ -207,11 +207,11 @@ class step_testcase extends advanced_testcase {
      */
     public function test_is_last_step($sortorder, $count, $isfirst, $islast) {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods(['get_sortorder', 'get_tour'])
+            ->onlyMethods(['get_sortorder', 'get_tour'])
             ->getMock();
 
         $tour = $this->getMockBuilder(\tool_usertours\tour::class)
-            ->setMethods(['count_steps'])
+            ->onlyMethods(['count_steps'])
             ->getMock();
 
         $step->expects($this->once())
@@ -362,7 +362,7 @@ class step_testcase extends advanced_testcase {
      */
     public function test_get_config_valid_keys($values, $key, $default, $tourconfig, $isforced, $forcedvalue, $expected) {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods(['get_target', 'get_targettype', 'get_tour'])
+            ->onlyMethods(['get_target', 'get_targettype', 'get_tour'])
             ->getMock();
 
         $rc = new \ReflectionClass(\tool_usertours\step::class);
@@ -494,7 +494,7 @@ class step_testcase extends advanced_testcase {
      */
     public function test_persist_non_dirty() {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'reload',
                 ])
@@ -525,7 +525,7 @@ class step_testcase extends advanced_testcase {
 
         // Mock the tour.
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'calculate_sortorder',
                     'reload',
@@ -574,7 +574,7 @@ class step_testcase extends advanced_testcase {
 
         // Mock the tour.
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'calculate_sortorder',
                     'reload',
@@ -616,7 +616,7 @@ class step_testcase extends advanced_testcase {
 
         // Mock the tour.
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'calculate_sortorder',
                     'reload',
@@ -668,7 +668,7 @@ class step_testcase extends advanced_testcase {
 
         // Mock the tour.
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'calculate_sortorder',
                     'reload',
@@ -707,7 +707,7 @@ class step_testcase extends advanced_testcase {
      */
     public function test_remove_non_persisted() {
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock()
             ;
 
@@ -727,7 +727,7 @@ class step_testcase extends advanced_testcase {
         $id = rand(1, 100);
 
         $tour = $this->getMockBuilder(\tool_usertours\tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'reset_step_sortorder',
                 ])
             ->getMock()
@@ -738,7 +738,7 @@ class step_testcase extends advanced_testcase {
             ;
 
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_tour',
                 ])
             ->getMock()
diff --git a/admin/tool/usertours/tests/tour_test.php b/admin/tool/usertours/tests/tour_test.php
index 2e8184a5ea8..536723375cd 100644
--- a/admin/tool/usertours/tests/tour_test.php
+++ b/admin/tool/usertours/tests/tour_test.php
@@ -193,7 +193,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_persist_non_dirty() {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods(['to_record'])
+            ->onlyMethods(['to_record'])
             ->getMock()
             ;
 
@@ -223,7 +223,7 @@ class tour_testcase extends advanced_testcase {
 
         // Mock the tour.
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'reload',
                 ])
@@ -272,7 +272,7 @@ class tour_testcase extends advanced_testcase {
 
         // Mock the tour.
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'reload',
                 ])
@@ -312,7 +312,7 @@ class tour_testcase extends advanced_testcase {
 
         // Mock the tour.
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'reload',
                 ])
@@ -360,7 +360,7 @@ class tour_testcase extends advanced_testcase {
 
         // Mock the tour.
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'to_record',
                     'reload',
                 ])
@@ -518,7 +518,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_remove_non_persisted() {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_steps',
                 ])
             ->getMock()
@@ -544,7 +544,7 @@ class tour_testcase extends advanced_testcase {
         $id = rand(1, 100);
 
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_steps',
                 ])
             ->getMock()
@@ -556,7 +556,7 @@ class tour_testcase extends advanced_testcase {
         $rcp->setValue($tour, $id);
 
         $step = $this->getMockBuilder(\tool_usertours\step::class)
-            ->setMethods([
+            ->onlyMethods([
                     'remove',
                 ])
             ->getMock()
@@ -683,7 +683,7 @@ class tour_testcase extends advanced_testcase {
         $this->setAdminUser();
 
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_id',
                     'get_config',
                     'is_enabled',
@@ -781,7 +781,7 @@ class tour_testcase extends advanced_testcase {
         $this->setAdminUser();
 
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_config',
                     'set_config',
                     'get_id',
@@ -839,7 +839,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_requested_user_reset() {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_id',
                 ])
             ->getMock()
@@ -863,7 +863,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_mark_user_completed() {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods([
+            ->onlyMethods([
                     'get_id',
                 ])
             ->getMock()
@@ -1039,7 +1039,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_get_filter_values($fullconfig, $filtername, $expectedvalues) {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods(['get_config'])
+            ->onlyMethods(['get_config'])
             ->getMock();
 
         $tour->expects($this->once())
@@ -1097,7 +1097,7 @@ class tour_testcase extends advanced_testcase {
      */
     public function test_set_filter_values_merge($currentvalues, $filtername, $newvalues, $expectedvalues) {
         $tour = $this->getMockBuilder(tour::class)
-            ->setMethods(['get_config', 'set_config'])
+            ->onlyMethods(['get_config', 'set_config'])
             ->getMock();
 
         $tour->expects($this->once())
diff --git a/analytics/tests/indicator_test.php b/analytics/tests/indicator_test.php
index ff7ff0c3b36..06b4b7a15c3 100644
--- a/analytics/tests/indicator_test.php
+++ b/analytics/tests/indicator_test.php
@@ -76,7 +76,7 @@ class analytics_indicator_testcase extends advanced_testcase {
 
         $indicator = new $indicatorclass();
         $indicatormock = $this->getMockBuilder(get_class($indicator))
-            ->setMethods(['calculate_sample'])
+            ->onlyMethods(['calculate_sample'])
             ->getMock();
         $indicatormock->method('calculate_sample')->willReturn($willreturn);
         $this->expectException(coding_exception::class);
diff --git a/analytics/tests/prediction_test.php b/analytics/tests/prediction_test.php
index 0fac8189714..43af3a6cb33 100644
--- a/analytics/tests/prediction_test.php
+++ b/analytics/tests/prediction_test.php
@@ -706,7 +706,7 @@ class core_analytics_prediction_testcase extends advanced_testcase {
         $endtime = 321;
         $sampleorigin = 'whatever';
 
-        $indicator = $this->getMockBuilder('test_indicator_max')->setMethods(['calculate_sample'])->getMock();
+        $indicator = $this->getMockBuilder('test_indicator_max')->onlyMethods(['calculate_sample'])->getMock();
         $indicator->expects($this->never())->method('calculate_sample');
 
         $existingcalcs = array(111 => 1, 222 => -1);
diff --git a/backup/moodle2/tests/restore_gradebook_structure_step_test.php b/backup/moodle2/tests/restore_gradebook_structure_step_test.php
index 26856de9597..5fdec30d36a 100644
--- a/backup/moodle2/tests/restore_gradebook_structure_step_test.php
+++ b/backup/moodle2/tests/restore_gradebook_structure_step_test.php
@@ -71,7 +71,7 @@ class core_backup_restore_gradebook_structure_step_testcase extends advanced_tes
      */
     public function test_rewrite_step_backup_file_for_legacy_freeze($source, $expected) {
         $restore = $this->getMockBuilder('\restore_gradebook_structure_step')
-            ->setMethods(null)
+            ->onlyMethods([])
             ->disableOriginalConstructor()
             ->getMock()
             ;
diff --git a/blocks/rss_client/tests/cron_test.php b/blocks/rss_client/tests/cron_test.php
index 48fe54d7cc0..fdead2892c9 100644
--- a/blocks/rss_client/tests/cron_test.php
+++ b/blocks/rss_client/tests/cron_test.php
@@ -121,11 +121,11 @@ class block_rss_client_cron_testcase extends advanced_testcase {
 
         // Run the scheduled task and have it fail.
         $task = $this->getMockBuilder(\block_rss_client\task\refreshfeeds::class)
-            ->setMethods(['fetch_feed'])
+            ->onlyMethods(['fetch_feed'])
             ->getMock();
 
         $piemock = $this->getMockBuilder(\moodle_simplepie::class)
-            ->setMethods(['error'])
+            ->onlyMethods(['error'])
             ->getMock();
 
         $piemock->method('error')
diff --git a/calendar/tests/calendar_event_exporter_test.php b/calendar/tests/calendar_event_exporter_test.php
index 8fc600e0be6..e974ae8024d 100644
--- a/calendar/tests/calendar_event_exporter_test.php
+++ b/calendar/tests/calendar_event_exporter_test.php
@@ -83,7 +83,7 @@ class core_calendar_event_exporter_testcase extends advanced_testcase {
         $class = \core_calendar\external\calendar_event_exporter::class;
         $mock = $this->getMockBuilder($class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
         $reflector = new ReflectionClass($class);
         $method = $reflector->getMethod('get_timestamp_min_limit');
@@ -140,7 +140,7 @@ class core_calendar_event_exporter_testcase extends advanced_testcase {
         $class = \core_calendar\external\calendar_event_exporter::class;
         $mock = $this->getMockBuilder($class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
         $reflector = new ReflectionClass($class);
         $method = $reflector->getMethod('get_timestamp_max_limit');
diff --git a/contentbank/tests/contentbank_test.php b/contentbank/tests/contentbank_test.php
index cdba73e97e8..3ed5b6339b4 100644
--- a/contentbank/tests/contentbank_test.php
+++ b/contentbank/tests/contentbank_test.php
@@ -558,7 +558,7 @@ class core_contentbank_testcase extends advanced_testcase {
             // Mock core_plugin_manager class and the method get_plugins_of_type.
             $pluginmanager = $this->getMockBuilder(\core_plugin_manager::class)
                 ->disableOriginalConstructor()
-                ->setMethods(['get_plugins_of_type'])
+                ->onlyMethods(['get_plugins_of_type'])
                 ->getMock();
 
             // Replace protected singletoninstance reference (core_plugin_manager property) with mock object.
diff --git a/course/tests/category_hooks_test.php b/course/tests/category_hooks_test.php
index 4a5cb9a6f97..17b1fff39ca 100644
--- a/course/tests/category_hooks_test.php
+++ b/course/tests/category_hooks_test.php
@@ -56,7 +56,7 @@ class core_course_category_hooks_testcase extends \advanced_testcase {
         // Setup mock object for \core_course_category.
         // Disable original constructor, since we can't use it directly since it is private.
         $mockcategory = $this->getMockBuilder(\core_course_category::class)
-            ->setMethods(['get_plugins_callback_function'])
+            ->onlyMethods(['get_plugins_callback_function'])
             ->disableOriginalConstructor()
             ->getMock();
 
diff --git a/favourites/tests/component_favourite_service_test.php b/favourites/tests/component_favourite_service_test.php
index cb56a431049..42f9b32f687 100644
--- a/favourites/tests/component_favourite_service_test.php
+++ b/favourites/tests/component_favourite_service_test.php
@@ -59,7 +59,7 @@ class component_favourite_service_testcase extends advanced_testcase {
     protected function get_mock_repository(array $mockstore) {
         // This mock will just store data in an array.
         $mockrepo = $this->getMockBuilder(\core_favourites\local\repository\favourite_repository_interface::class)
-            ->setMethods([])
+            ->onlyMethods([])
             ->getMock();
         $mockrepo->expects($this->any())
             ->method('add')
diff --git a/favourites/tests/user_favourite_service_test.php b/favourites/tests/user_favourite_service_test.php
index f44a6386e0f..c7bd392a373 100644
--- a/favourites/tests/user_favourite_service_test.php
+++ b/favourites/tests/user_favourite_service_test.php
@@ -59,7 +59,7 @@ class user_favourite_service_testcase extends advanced_testcase {
     protected function get_mock_repository(array $mockstore) {
         // This mock will just store data in an array.
         $mockrepo = $this->getMockBuilder(\core_favourites\local\repository\favourite_repository_interface::class)
-            ->setMethods([])
+            ->onlyMethods([])
             ->getMock();
         $mockrepo->expects($this->any())
             ->method('add')
diff --git a/files/converter/unoconv/tests/converter_test.php b/files/converter/unoconv/tests/converter_test.php
index 455289f9cef..37808fd2d1f 100644
--- a/files/converter/unoconv/tests/converter_test.php
+++ b/files/converter/unoconv/tests/converter_test.php
@@ -52,9 +52,9 @@ class fileconverter_unoconv_converter_testcase extends advanced_testcase {
      *                  If no methods are specified, only abstract functions are mocked.
      * @return  \fileconverter_unoconv\converter
      */
-    protected function get_testable_mock($mockedmethods = null) {
+    protected function get_testable_mock($mockedmethods = []) {
         $converter = $this->getMockBuilder(\fileconverter_unoconv\converter::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->getMock();
 
         return $converter;
diff --git a/files/tests/converter_test.php b/files/tests/converter_test.php
index e345c1e40d9..0e8d9d2bc6f 100644
--- a/files/tests/converter_test.php
+++ b/files/tests/converter_test.php
@@ -47,7 +47,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     protected function get_testable_mock($mockedmethods = []) {
         $converter = $this->getMockBuilder(\core_files\converter::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->getMockForAbstractClass();
 
         return $converter;
@@ -61,7 +61,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     protected function get_testable_conversion($mockedmethods = []) {
         $conversion = $this->getMockBuilder(\core_files\conversion::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->setConstructorArgs([0, (object) []])
             ->getMock();
 
@@ -77,7 +77,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     protected function get_mocked_converter($mockedmethods = []) {
         $converter = $this->getMockBuilder(\core_files\converter_interface::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->getMockForAbstractClass();
 
         return $converter;
@@ -92,7 +92,7 @@ class core_files_converter_testcase extends advanced_testcase {
      *                  If no methods are specified, only abstract functions are mocked.
      * @return  stored_file
      */
-    protected function get_stored_file($filecontent = 'content', $filename = null, $filerecord = [], $mockedmethods = null) {
+    protected function get_stored_file($filecontent = 'content', $filename = null, $filerecord = [], $mockedmethods = []) {
         global $CFG;
 
         $contenthash = sha1($filecontent);
@@ -106,7 +106,7 @@ class core_files_converter_testcase extends advanced_testcase {
         $filerecord['id'] = 42;
 
         $file = $this->getMockBuilder(stored_file::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->setConstructorArgs([get_file_storage(), (object) $filerecord])
             ->getMock();
 
@@ -145,7 +145,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     protected function get_file_storage_mock($mockedmethods = []) {
         $fs = $this->getMockBuilder(\file_storage::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -248,7 +248,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     public function test_get_document_converter_classes_plugin_class_requirements_not_met() {
         $plugin = $this->getMockBuilder(\core_file_converter_requirements_not_met_test::class)
-            ->setMethods()
+            ->onlyMethods([])
             ->getMock();
 
         $converter = $this->get_testable_mock(['get_enabled_plugins']);
@@ -267,7 +267,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     public function test_get_document_converter_classes_plugin_class_met_not_supported() {
         $plugin = $this->getMockBuilder(\core_file_converter_type_not_supported_test::class)
-            ->setMethods()
+            ->onlyMethods([])
             ->getMock();
 
         $converter = $this->get_testable_mock(['get_enabled_plugins']);
@@ -286,7 +286,7 @@ class core_files_converter_testcase extends advanced_testcase {
      */
     public function test_get_document_converter_classes_plugin_class_met_and_supported() {
         $plugin = $this->getMockBuilder(\core_file_converter_type_supported_test::class)
-            ->setMethods()
+            ->onlyMethods([])
             ->getMock();
         $classname = get_class($plugin);
 
diff --git a/lib/antivirus/clamav/tests/scanner_test.php b/lib/antivirus/clamav/tests/scanner_test.php
index fb57b69114c..ce082333c69 100644
--- a/lib/antivirus/clamav/tests/scanner_test.php
+++ b/lib/antivirus/clamav/tests/scanner_test.php
@@ -44,7 +44,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
 
     public function test_scan_file_not_exists() {
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods(array('scan_file_execute_commandline', 'message_admins'))
+            ->onlyMethods(array('scan_file_execute_commandline', 'message_admins'))
             ->getMock();
 
         // Test specifying file that does not exist.
@@ -63,7 +63,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_config',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
         // Initiate mock scanning with configuration setting to use commandline.
         $configmap = array(array('runningmethod', 'commandline'));
@@ -104,7 +104,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_config',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
         // Initiate mock scanning with configuration setting to use commandline.
         $configmap = array(array('runningmethod', 'commandline'));
@@ -146,7 +146,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_scanning_notice',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
 
         // Configure scan_file_execute_commandline and scan_file_execute_socket
@@ -193,7 +193,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_scanning_notice',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
 
         // Configure scan_file_execute_commandline and scan_file_execute_socket
@@ -242,7 +242,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
                 'get_config',
                 'get_scanning_notice',
         );
-        $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')->setMethods($methods)->getMock();
+        $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')->onlyMethods($methods)->getMock();
 
         // Configure scan_file_execute_commandline and scan_file_execute_unixsocket
         // method stubs to behave as if there is a scanning error (SCAN_RESULT_ERROR).
@@ -273,7 +273,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_config',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
         // Initiate mock scanning with configuration setting to use unixsocket.
         $configmap = array(array('runningmethod', 'unixsocket'));
@@ -307,7 +307,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_config',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
         // Initiate mock scanning with configuration setting to use unixsocket.
         $configmap = array(array('runningmethod', 'unixsocket'));
@@ -342,7 +342,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_scanning_notice',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
         // Initiate mock scanning with configuration setting to do nothing on
         // scanning error and using unixsocket.
@@ -380,7 +380,7 @@ class antivirus_clamav_scanner_testcase extends advanced_testcase {
             'get_scanning_notice',
         );
         $antivirus = $this->getMockBuilder('\antivirus_clamav\scanner')
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
 
         // Initiate mock scanning with configuration setting to act like virus on
diff --git a/lib/filestorage/tests/file_system_filedir_test.php b/lib/filestorage/tests/file_system_filedir_test.php
index bc6c7846a9a..63918c38b81 100644
--- a/lib/filestorage/tests/file_system_filedir_test.php
+++ b/lib/filestorage/tests/file_system_filedir_test.php
@@ -99,14 +99,14 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
      *                  If no methods are specified, only abstract functions are mocked.
      * @return stored_file
      */
-    protected function get_stored_file($filecontent, $filename = null, $mockedmethods = null) {
+    protected function get_stored_file($filecontent, $filename = null, $mockedmethods = []) {
         $contenthash = file_storage::hash_from_string($filecontent);
         if (empty($filename)) {
             $filename = $contenthash;
         }
 
         $file = $this->getMockBuilder(stored_file::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->setConstructorArgs([
                 get_file_storage(),
                 (object) [
@@ -129,7 +129,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
      */
     protected function get_testable_mock($mockedmethods = []) {
         $fs = $this->getMockBuilder(file_system_filedir::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->getMock();
 
         return $fs;
@@ -321,7 +321,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
 
         $file = $this->getMockBuilder('stored_file')
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'sync_external_file',
                 'get_contenthash',
             ])
@@ -441,7 +441,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
 
         $fs = $this->getMockBuilder(file_system_filedir::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'get_local_path_from_storedfile',
             ])
             ->getMock();
@@ -997,7 +997,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
         global $DB;
 
         $DB = $this->getMockBuilder(\moodle_database::class)
-            ->setMethods(['record_exists'])
+            ->onlyMethods(['record_exists'])
             ->getMockForAbstractClass();
 
         $DB->expects($this->never())
@@ -1031,7 +1031,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
         $vfileroot = $this->setup_vfile_root($filedircontent);
 
         $DB = $this->getMockBuilder(\moodle_database::class)
-            ->setMethods(['record_exists'])
+            ->onlyMethods(['record_exists'])
             ->getMockForAbstractClass();
 
         $DB->method('record_exists')->willReturn(true);
@@ -1064,7 +1064,7 @@ class core_files_file_system_filedir_testcase extends advanced_testcase {
         $vfileroot = $this->setup_vfile_root($filedircontent);
 
         $DB = $this->getMockBuilder(\moodle_database::class)
-            ->setMethods(['record_exists'])
+            ->onlyMethods(['record_exists'])
             ->getMockForAbstractClass();
 
         $DB->method('record_exists')->willReturn(false);
diff --git a/lib/filestorage/tests/file_system_test.php b/lib/filestorage/tests/file_system_test.php
index 4858c1c7c96..c85f572c24f 100644
--- a/lib/filestorage/tests/file_system_test.php
+++ b/lib/filestorage/tests/file_system_test.php
@@ -70,14 +70,14 @@ class core_files_file_system_testcase extends advanced_testcase {
      *                  If no methods are specified, only abstract functions are mocked.
      * @return stored_file
      */
-    protected function get_stored_file($filecontent, $filename = null, $mockedmethods = null) {
+    protected function get_stored_file($filecontent, $filename = null, $mockedmethods = []) {
         $contenthash = file_storage::hash_from_string($filecontent);
         if (empty($filename)) {
             $filename = $contenthash;
         }
 
         $file = $this->getMockBuilder(stored_file::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->setConstructorArgs([
                 get_file_storage(),
                 (object) [
@@ -100,7 +100,7 @@ class core_files_file_system_testcase extends advanced_testcase {
      */
     protected function get_testable_mock($mockedmethods = []) {
         $fs = $this->getMockBuilder(file_system::class)
-            ->setMethods($mockedmethods)
+            ->onlyMethods($mockedmethods)
             ->getMockForAbstractClass();
 
         return $fs;
@@ -514,7 +514,7 @@ class core_files_file_system_testcase extends advanced_testcase {
         $contenthash = file_storage::hash_from_string($filecontent);
 
         $DB = $this->getMockBuilder(\moodle_database::class)
-            ->setMethods(['record_exists'])
+            ->onlyMethods(['record_exists'])
             ->getMockForAbstractClass();
         $DB->method('record_exists')->willReturn(true);
 
@@ -538,7 +538,7 @@ class core_files_file_system_testcase extends advanced_testcase {
         $contenthash = file_storage::hash_from_string($filecontent);
 
         $DB = $this->getMockBuilder(\moodle_database::class)
-            ->setMethods(['record_exists'])
+            ->onlyMethods(['record_exists'])
             ->getMockForAbstractClass();
         $DB->method('record_exists')->willReturn(false);
 
@@ -615,7 +615,7 @@ class core_files_file_system_testcase extends advanced_testcase {
             ->willReturn(__FILE__);
 
         $packer = $this->getMockBuilder(file_packer::class)
-            ->setMethods(['list_files'])
+            ->onlyMethods(['list_files'])
             ->getMockForAbstractClass();
 
         $packer->expects($this->once())
@@ -648,7 +648,7 @@ class core_files_file_system_testcase extends advanced_testcase {
             ->willReturn(__FILE__);
 
         $packer = $this->getMockBuilder(file_packer::class)
-            ->setMethods(['extract_to_pathname'])
+            ->onlyMethods(['extract_to_pathname'])
             ->getMockForAbstractClass();
 
         $packer->expects($this->once())
@@ -681,7 +681,7 @@ class core_files_file_system_testcase extends advanced_testcase {
             ->willReturn(__FILE__);
 
         $packer = $this->getMockBuilder(file_packer::class)
-            ->setMethods(['extract_to_storage'])
+            ->onlyMethods(['extract_to_storage'])
             ->getMockForAbstractClass();
 
         $packer->expects($this->once())
@@ -720,7 +720,7 @@ class core_files_file_system_testcase extends advanced_testcase {
             ->willReturn(__FILE__);
 
         $archive = $this->getMockBuilder(file_archive::class)
-            ->setMethods([
+            ->onlyMethods([
                 'add_directory',
                 'add_file_from_pathname',
             ])
@@ -757,7 +757,7 @@ class core_files_file_system_testcase extends advanced_testcase {
             ->willReturn($filepath);
 
         $archive = $this->getMockBuilder(file_archive::class)
-            ->setMethods([
+            ->onlyMethods([
                 'add_directory',
                 'add_file_from_pathname',
             ])
diff --git a/lib/table/tests/local/filter/filterset_test.php b/lib/table/tests/local/filter/filterset_test.php
index a8887e063ba..bc58d067ce3 100644
--- a/lib/table/tests/local/filter/filterset_test.php
+++ b/lib/table/tests/local/filter/filterset_test.php
@@ -135,7 +135,7 @@ class filterset_test extends advanced_testcase {
     public function test_add_filter_validated_type(): void {
         $namefilter = $this->getMockBuilder(filter::class)
             ->setConstructorArgs(['name'])
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
         $namefilter->add_filter_value('rosie');
 
@@ -188,7 +188,7 @@ class filterset_test extends advanced_testcase {
         // Add a filter to the list.
         // This is the 'name' filter.
         $namefilter = $this->getMockBuilder(filter::class)
-            ->setMethods(null)
+            ->onlyMethods([])
             ->setConstructorArgs([$filtername])
             ->getMock();
 
@@ -207,7 +207,7 @@ class filterset_test extends advanced_testcase {
     public function test_add_filter_from_params(): void {
         $filtername = "name";
         $otherfilter = $this->getMockBuilder(filter::class)
-            ->setMethods(null)
+            ->onlyMethods([])
             ->setConstructorArgs([$filtername])
             ->getMock();
 
@@ -254,7 +254,7 @@ class filterset_test extends advanced_testcase {
     public function test_add_filter_from_params_invalid(): void {
         $filtername = "name";
         $otherfilter = $this->getMockBuilder(filter::class)
-            ->setMethods(null)
+            ->onlyMethods([])
             ->setConstructorArgs([$filtername])
             ->getMock();
 
diff --git a/lib/tests/accesslib_test.php b/lib/tests/accesslib_test.php
index 257eea0cecd..116db957fc4 100644
--- a/lib/tests/accesslib_test.php
+++ b/lib/tests/accesslib_test.php
@@ -4233,7 +4233,7 @@ class core_accesslib_testcase extends advanced_testcase {
     public function test_is_parent_of(string $contextpath, string $testpath, bool $testself, bool $expected): void {
         $context = $this->getMockBuilder(\context::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'get_url',
                 'get_capabilities',
             ])
@@ -4245,7 +4245,7 @@ class core_accesslib_testcase extends advanced_testcase {
 
         $comparisoncontext = $this->getMockBuilder(\context::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'get_url',
                 'get_capabilities',
             ])
@@ -4335,7 +4335,7 @@ class core_accesslib_testcase extends advanced_testcase {
     public function test_is_child_of(string $contextpath, string $testpath, bool $testself, bool $expected): void {
         $context = $this->getMockBuilder(\context::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'get_url',
                 'get_capabilities',
             ])
@@ -4347,7 +4347,7 @@ class core_accesslib_testcase extends advanced_testcase {
 
         $comparisoncontext = $this->getMockBuilder(\context::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'get_url',
                 'get_capabilities',
             ])
diff --git a/lib/tests/completionlib_test.php b/lib/tests/completionlib_test.php
index 6267d18caab..337980770fc 100644
--- a/lib/tests/completionlib_test.php
+++ b/lib/tests/completionlib_test.php
@@ -129,7 +129,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('is_enabled', 'get_data', 'internal_get_state', 'internal_set_data',
+        $mockbuilder->onlyMethods(array('is_enabled', 'get_data', 'internal_get_state', 'internal_set_data',
                                        'user_can_override_completion'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
         $cm = (object)array('id'=>13, 'course'=>42);
@@ -453,7 +453,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('is_enabled', 'get_data', 'internal_set_data', 'update_state'));
+        $mockbuilder->onlyMethods(array('is_enabled', 'get_data', 'internal_set_data', 'update_state'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
         $cm = (object)array('id'=>13, 'course'=>42);
 
@@ -542,7 +542,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('delete_all_state', 'get_tracked_users', 'update_state'));
+        $mockbuilder->onlyMethods(array('delete_all_state', 'get_tracked_users', 'update_state'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
         $c = $mockbuilder->getMock();
 
@@ -756,7 +756,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('get_tracked_users'));
+        $mockbuilder->onlyMethods(array('get_tracked_users'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
         $c = $mockbuilder->getMock();
 
@@ -790,7 +790,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('get_tracked_users'));
+        $mockbuilder->onlyMethods(array('get_tracked_users'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
         $c = $mockbuilder->getMock();
 
@@ -844,7 +844,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->mock_setup();
 
         $mockbuilder = $this->getMockBuilder('completion_info');
-        $mockbuilder->setMethods(array('is_enabled', 'update_state'));
+        $mockbuilder->onlyMethods(array('is_enabled', 'update_state'));
         $mockbuilder->setConstructorArgs(array((object)array('id' => 42)));
 
         $cm = (object)array('course'=>42, 'id'=>13, 'completion'=>0, 'completiongradeitemnumber'=>null);
diff --git a/lib/tests/content/export/exportable_items/exportable_filearea_test.php b/lib/tests/content/export/exportable_items/exportable_filearea_test.php
index 4e6d09ee2c8..bae10175ab1 100644
--- a/lib/tests/content/export/exportable_items/exportable_filearea_test.php
+++ b/lib/tests/content/export/exportable_items/exportable_filearea_test.php
@@ -224,7 +224,7 @@ class exportable_filearea_test extends advanced_testcase {
     ): exported_item {
         $archive = $this->getMockBuilder(zipwriter::class)
             ->setConstructorArgs([$this->getMockBuilder(\ZipStream\ZipStream::class)->getmock()])
-            ->setMethods([
+            ->onlyMethods([
                 'add_file_from_stored_file',
                 'is_file_in_archive',
             ])
diff --git a/lib/tests/content/export/exportable_items/exportable_stored_file_test.php b/lib/tests/content/export/exportable_items/exportable_stored_file_test.php
index dab75e5d1c5..a3fbb22fa41 100644
--- a/lib/tests/content/export/exportable_items/exportable_stored_file_test.php
+++ b/lib/tests/content/export/exportable_items/exportable_stored_file_test.php
@@ -209,7 +209,7 @@ class exportable_stored_file_test extends advanced_testcase {
     ): void {
         $archive = $this->getMockBuilder(zipwriter::class)
             ->setConstructorArgs([$this->getMockBuilder(\ZipStream\ZipStream::class)->getmock()])
-            ->setMethods([
+            ->onlyMethods([
                 'add_file_from_stored_file',
             ])
             ->getMock();
diff --git a/lib/tests/content/export/exportable_items/exportable_textarea_test.php b/lib/tests/content/export/exportable_items/exportable_textarea_test.php
index 51b1196b3c3..e42f0ca5952 100644
--- a/lib/tests/content/export/exportable_items/exportable_textarea_test.php
+++ b/lib/tests/content/export/exportable_items/exportable_textarea_test.php
@@ -309,7 +309,7 @@ EOF;
     ): void {
         $archive = $this->getMockBuilder(zipwriter::class)
             ->setConstructorArgs([$this->getMockBuilder(\ZipStream\ZipStream::class)->getmock()])
-            ->setMethods([
+            ->onlyMethods([
                 'is_file_in_archive',
                 'add_file_from_string',
                 'add_file_from_stored_file',
@@ -357,7 +357,7 @@ EOF;
     ): void {
         $archive = $this->getMockBuilder(zipwriter::class)
             ->setConstructorArgs([$this->getMockBuilder(\ZipStream\ZipStream::class)->getmock()])
-            ->setMethods([
+            ->onlyMethods([
                 'add_file_from_stored_file',
                 'add_file_from_string',
                 'add_file_from_template',
diff --git a/lib/tests/content/export/exporters/course_exporter_test.php b/lib/tests/content/export/exporters/course_exporter_test.php
index 211575633e5..6026fce1582 100644
--- a/lib/tests/content/export/exporters/course_exporter_test.php
+++ b/lib/tests/content/export/exporters/course_exporter_test.php
@@ -149,7 +149,7 @@ class course_exporter_test extends advanced_testcase {
     protected function get_mocked_zipwriter(?array $methods = []): zipwriter {
         return $this->getMockBuilder(zipwriter::class)
             ->setConstructorArgs([$this->getMockBuilder(\ZipStream\ZipStream::class)->getmock()])
-            ->setMethods($methods)
+            ->onlyMethods($methods)
             ->getMock();
     }
 }
diff --git a/lib/tests/curl_security_helper_test.php b/lib/tests/curl_security_helper_test.php
index d5a3d70907b..7a29b95137d 100644
--- a/lib/tests/curl_security_helper_test.php
+++ b/lib/tests/curl_security_helper_test.php
@@ -48,7 +48,7 @@ class core_curl_security_helper_testcase extends advanced_testcase {
     public function test_curl_security_helper_url_is_blocked($dns, $url, $blockedhosts, $allowedports, $expected) {
         $this->resetAfterTest(true);
         $helper = $this->getMockBuilder('\core\files\curl_security_helper')
-                        ->setMethods(['get_host_list_by_name'])
+                        ->onlyMethods(['get_host_list_by_name'])
                         ->getMock();
 
         // Override the get host list method to return hard coded values based on a mapping provided by $dns.
diff --git a/lib/tests/h5p_get_content_types_task_test.php b/lib/tests/h5p_get_content_types_task_test.php
index 00ac6183d27..572e49ebfbb 100644
--- a/lib/tests/h5p_get_content_types_task_test.php
+++ b/lib/tests/h5p_get_content_types_task_test.php
@@ -73,7 +73,7 @@ class h5p_get_content_types_task_testcase extends advanced_testcase {
 
         // Mock implementation of \core\task\h5p_get_content_types_task::get_core to avoid external systems.
         $mocktask = $this->getMockBuilder(\core\task\h5p_get_content_types_task::class)
-            ->setMethods(['get_core'])
+            ->onlyMethods(['get_core'])
             ->getMock();
 
         $mocktask->expects($this->any())
diff --git a/lib/tests/task_database_logger_test.php b/lib/tests/task_database_logger_test.php
index 4ae0a661311..73b656d9042 100644
--- a/lib/tests/task_database_logger_test.php
+++ b/lib/tests/task_database_logger_test.php
@@ -104,7 +104,7 @@ class task_database_logger_testcase extends advanced_testcase {
         file_put_contents($logpath, 'Example content');
 
         $task = $this->getMockBuilder(\core\task\adhoc_task::class)
-            ->setMethods(['get_component', 'execute'])
+            ->onlyMethods(['get_component', 'execute'])
             ->getMock();
 
         $task->method('get_component')->willReturn('core_test');
@@ -165,7 +165,7 @@ class task_database_logger_testcase extends advanced_testcase {
         file_put_contents($logpath, 'Example content');
 
         $task = $this->getMockBuilder(\core\task\adhoc_task::class)
-            ->setMethods(['get_component', 'execute'])
+            ->onlyMethods(['get_component', 'execute'])
             ->getMock();
 
         $task->method('get_component')->willReturn('core_test');
@@ -197,7 +197,7 @@ class task_database_logger_testcase extends advanced_testcase {
         file_put_contents($logpath, 'Example content');
 
         $task = $this->getMockBuilder(\core\task\adhoc_task::class)
-            ->setMethods(['get_component', 'execute', 'get_userid'])
+            ->onlyMethods(['get_component', 'execute', 'get_userid'])
             ->getMock();
 
         $task->method('get_component')->willReturn('core_test');
diff --git a/mod/data/tests/lib_test.php b/mod/data/tests/lib_test.php
index 88d71666ef5..9eae38fa9da 100644
--- a/mod/data/tests/lib_test.php
+++ b/mod/data/tests/lib_test.php
@@ -914,7 +914,7 @@ class mod_data_lib_testcase extends advanced_testcase {
         // Note: Use the actual test class here rather than the abstract because are testing concrete methods.
         $this->DB = $DB;
         $DB = $this->getMockBuilder(get_class($DB))
-            ->setMethods(['set_field'])
+            ->onlyMethods(['set_field'])
             ->getMock();
 
         $DB->expects($this->exactly((int) $expectupdate))
diff --git a/mod/quiz/accessrule/seb/tests/access_manager_test.php b/mod/quiz/accessrule/seb/tests/access_manager_test.php
index 6952ec010ce..262ac9a65d7 100644
--- a/mod/quiz/accessrule/seb/tests/access_manager_test.php
+++ b/mod/quiz/accessrule/seb/tests/access_manager_test.php
@@ -330,7 +330,7 @@ class quizacces_seb_access_manager_testcase extends advanced_testcase {
     public function test_should_validate_basic_header($type, $expected) {
         $accessmanager = $this->getMockBuilder(access_manager::class)
             ->disableOriginalConstructor()
-            ->setMethods(['get_seb_use_type'])
+            ->onlyMethods(['get_seb_use_type'])
             ->getMock();
         $accessmanager->method('get_seb_use_type')->willReturn($type);
 
@@ -364,7 +364,7 @@ class quizacces_seb_access_manager_testcase extends advanced_testcase {
     public function test_should_validate_config_key($type, $expected) {
         $accessmanager = $this->getMockBuilder(access_manager::class)
             ->disableOriginalConstructor()
-            ->setMethods(['get_seb_use_type'])
+            ->onlyMethods(['get_seb_use_type'])
             ->getMock();
         $accessmanager->method('get_seb_use_type')->willReturn($type);
 
@@ -397,7 +397,7 @@ class quizacces_seb_access_manager_testcase extends advanced_testcase {
     public function test_should_validate_browser_exam_key($type, $expected) {
         $accessmanager = $this->getMockBuilder(access_manager::class)
             ->disableOriginalConstructor()
-            ->setMethods(['get_seb_use_type'])
+            ->onlyMethods(['get_seb_use_type'])
             ->getMock();
         $accessmanager->method('get_seb_use_type')->willReturn($type);
 
diff --git a/privacy/tests/manager_test.php b/privacy/tests/manager_test.php
index 11a544fe7c2..4de5f84c101 100644
--- a/privacy/tests/manager_test.php
+++ b/privacy/tests/manager_test.php
@@ -57,7 +57,7 @@ class privacy_manager_testcase extends advanced_testcase {
      */
     protected function get_mock_manager_with_core_components($componentnames) {
         $mock = $this->getMockBuilder(\core_privacy\manager::class)
-            ->setMethods(['get_component_list'])
+            ->onlyMethods(['get_component_list'])
             ->getMock();
         $mock->expects($this->any())
             ->method('get_component_list')
@@ -336,7 +336,7 @@ class privacy_manager_testcase extends advanced_testcase {
         $mockman = $this->get_mock_manager_with_core_components(['mod_component_broken', 'mod_component_a']);
 
         $observer = $this->getMockBuilder(\core_privacy\manager_observer::class)
-            ->setMethods(['handle_component_failure'])
+            ->onlyMethods(['handle_component_failure'])
             ->getMock();
         $mockman->set_observer($observer);
 
@@ -374,7 +374,7 @@ class privacy_manager_testcase extends advanced_testcase {
         $contextid = $context->id;
 
         $observer = $this->getMockBuilder(\core_privacy\manager_observer::class)
-            ->setMethods(['handle_component_failure'])
+            ->onlyMethods(['handle_component_failure'])
             ->getMock();
         $mockman->set_observer($observer);
 
@@ -409,7 +409,7 @@ class privacy_manager_testcase extends advanced_testcase {
         $contextid = $context->id;
 
         $observer = $this->getMockBuilder(\core_privacy\manager_observer::class)
-            ->setMethods(['handle_component_failure'])
+            ->onlyMethods(['handle_component_failure'])
             ->getMock();
         $mockman->set_observer($observer);
 
@@ -443,7 +443,7 @@ class privacy_manager_testcase extends advanced_testcase {
         $context = \context_system::instance();
 
         $observer = $this->getMockBuilder(\core_privacy\manager_observer::class)
-            ->setMethods(['handle_component_failure'])
+            ->onlyMethods(['handle_component_failure'])
             ->getMock();
         $mockman->set_observer($observer);
 
@@ -473,7 +473,7 @@ class privacy_manager_testcase extends advanced_testcase {
         $context = \context_system::instance();
 
         $observer = $this->getMockBuilder(\core_privacy\manager_observer::class)
-            ->setMethods(['handle_component_failure'])
+            ->onlyMethods(['handle_component_failure'])
             ->getMock();
         $mockman->set_observer($observer);
 
diff --git a/privacy/tests/sitepolicy_test.php b/privacy/tests/sitepolicy_test.php
index 3589829f5d9..157d62a36b2 100644
--- a/privacy/tests/sitepolicy_test.php
+++ b/privacy/tests/sitepolicy_test.php
@@ -234,7 +234,7 @@ class sitepolicy_test extends advanced_testcase {
         require_once($CFG->dirroot.'/privacy/tests/fixtures/mock_sitepolicy_handler.php');
 
         $mock = $this->getMockBuilder(\core_privacy\local\sitepolicy\manager::class)
-            ->setMethods(['get_all_handlers'])
+            ->onlyMethods(['get_all_handlers'])
             ->getMock();
         $mock->expects($this->any())
             ->method('get_all_handlers')
diff --git a/privacy/tests/tests_content_writer_test.php b/privacy/tests/tests_content_writer_test.php
index 0e5759a65f0..f3a86984995 100644
--- a/privacy/tests/tests_content_writer_test.php
+++ b/privacy/tests/tests_content_writer_test.php
@@ -523,7 +523,7 @@ class tests_content_writer_test extends advanced_testcase {
         $contenthash = file_storage::hash_from_string($filecontent);
 
         $file = $this->getMockBuilder(stored_file::class)
-            ->setMethods(null)
+            ->onlyMethods([])
             ->setConstructorArgs([
                 get_file_storage(),
                 (object) [
diff --git a/repository/dropbox/tests/api_test.php b/repository/dropbox/tests/api_test.php
index a7ae2c3f205..a0dd8c1e1ee 100644
--- a/repository/dropbox/tests/api_test.php
+++ b/repository/dropbox/tests/api_test.php
@@ -83,7 +83,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_has_additional_results($result, $expected) {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
 
         $this->assertEquals($expected, $mock->has_additional_results($result));
@@ -159,7 +159,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_check_and_handle_api_errors($info, $data, $exception, $exceptionmessage) {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
 
         $mock->info = $info;
@@ -254,7 +254,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_supports_thumbnail($entry, $expected) {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(null)
+            ->onlyMethods([])
             ->getMock();
 
         $this->assertEquals($expected, $mock->supports_thumbnail($entry));
@@ -266,7 +266,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_logout_revocation() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(['fetch_dropbox_data'])
+            ->onlyMethods(['fetch_dropbox_data'])
             ->getMock();
 
         $mock->expects($this->once())
@@ -282,7 +282,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_logout_revocation_catch_auth_exception() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(['fetch_dropbox_data'])
+            ->onlyMethods(['fetch_dropbox_data'])
             ->getMock();
 
         $mock->expects($this->once())
@@ -298,7 +298,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_logout_revocation_does_not_catch_other_exceptions() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods(['fetch_dropbox_data'])
+            ->onlyMethods(['fetch_dropbox_data'])
             ->getMock();
 
         $mock->expects($this->once())
@@ -315,7 +315,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_fetch_dropbox_data_endpoint() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'request',
                 'get_api_endpoint',
                 'get_content_endpoint',
@@ -350,7 +350,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_fetch_dropbox_data_postfields_null() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'request',
             ])
             ->getMock();
@@ -377,7 +377,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_fetch_dropbox_data_postfields_data() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'request',
             ])
             ->getMock();
@@ -405,7 +405,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_fetch_dropbox_data_recurse_on_additional_records() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'request',
                 'get_api_endpoint',
             ])
@@ -456,7 +456,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_fetch_dropbox_content() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'request',
                 'setHeader',
                 'get_content_endpoint',
@@ -514,7 +514,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_get_file_share_info_existing() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'fetch_dropbox_data',
                 'normalize_file_share_info',
             ])
@@ -547,7 +547,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_get_file_share_info_new() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'fetch_dropbox_data',
                 'normalize_file_share_info',
             ])
@@ -588,7 +588,7 @@ class repository_dropbox_api_testcase extends advanced_testcase {
     public function test_get_file_share_info_new_failure() {
         $mock = $this->getMockBuilder(\repository_dropbox\dropbox::class)
             ->disableOriginalConstructor()
-            ->setMethods([
+            ->onlyMethods([
                 'fetch_dropbox_data',
                 'normalize_file_share_info',
             ])
diff --git a/search/tests/area_category_test.php b/search/tests/area_category_test.php
index 9aa25625aa1..c0558688dae 100644
--- a/search/tests/area_category_test.php
+++ b/search/tests/area_category_test.php
@@ -42,7 +42,7 @@ class search_area_category_testcase extends advanced_testcase {
     protected function get_mocked_area($areaid) {
         $builder = $this->getMockBuilder('\core_search\base');
         $builder->disableOriginalConstructor();
-        $builder->setMethods(array('get_area_id'));
+        $builder->onlyMethods(array('get_area_id'));
         $area = $builder->getMockForAbstractClass();
         $area->method('get_area_id')->willReturn($areaid);
 
diff --git a/search/tests/base_activity_test.php b/search/tests/base_activity_test.php
index c58719911be..0d855badf75 100644
--- a/search/tests/base_activity_test.php
+++ b/search/tests/base_activity_test.php
@@ -163,7 +163,7 @@ class search_base_activity_testcase extends advanced_testcase {
         // with required methods stubbed.
         $builder = $this->getMockBuilder('\core_search\base_activity');
         $builder->disableOriginalConstructor();
-        $builder->setMethods(array('get_module_name', 'get_component_name'));
+        $builder->onlyMethods(array('get_module_name', 'get_component_name'));
         $stub = $builder->getMockForAbstractClass();
         $stub->method('get_module_name')->willReturn($module);
         $stub->method('get_component_name')->willReturn($component);
@@ -380,7 +380,7 @@ class search_base_activity_testcase extends advanced_testcase {
     public function test_get_doc_icon() {
         $baseactivity = $this->getMockBuilder('\core_search\base_activity')
             ->disableOriginalConstructor()
-            ->setMethods(array('get_module_name'))
+            ->onlyMethods(array('get_module_name'))
             ->getMockForAbstractClass();
 
         $baseactivity->method('get_module_name')->willReturn('test_activity');
diff --git a/search/tests/base_test.php b/search/tests/base_test.php
index f0a2ff17786..22091049f82 100644
--- a/search/tests/base_test.php
+++ b/search/tests/base_test.php
@@ -115,7 +115,7 @@ class search_base_testcase extends advanced_testcase {
         // with required methods stubbed.
         $builder = $this->getMockBuilder('\core_search\base');
         $builder->disableOriginalConstructor();
-        $builder->setMethods(array('get_search_fileareas', 'get_component_name'));
+        $builder->onlyMethods(array('get_search_fileareas', 'get_component_name'));
         $stub = $builder->getMockForAbstractClass();
         $stub->method('get_search_fileareas')->willReturn(array($filearea));
         $stub->method('get_component_name')->willReturn($component);
diff --git a/webservice/xmlrpc/tests/locallib_test.php b/webservice/xmlrpc/tests/locallib_test.php
index 54371da1ae8..d35da868ac1 100644
--- a/webservice/xmlrpc/tests/locallib_test.php
+++ b/webservice/xmlrpc/tests/locallib_test.php
@@ -61,7 +61,7 @@ class webservice_xmlrpc_locallib_testcase extends advanced_testcase {
     public function test_prepare_response($returnsdesc, $returns, $expected) {
         $server = $this->getMockBuilder('webservice_xmlrpc_server')
                        ->disableOriginalConstructor()
-                       ->setMethods(null)
+                       ->onlyMethods([])
                        ->getMock();
 
         $rc = new \ReflectionClass('webservice_xmlrpc_server');
@@ -97,7 +97,7 @@ class webservice_xmlrpc_locallib_testcase extends advanced_testcase {
     public function test_generate_error($exception, $code, $expected) {
         $server = $this->getMockBuilder('webservice_xmlrpc_server')
                 ->disableOriginalConstructor()
-                ->setMethods(null)
+                ->onlyMethods([])
                 ->getMock();
 
         $rc = new \ReflectionClass('webservice_xmlrpc_server');
diff --git a/webservice/xmlrpc/tests/xmlrpc_server_test.php b/webservice/xmlrpc/tests/xmlrpc_server_test.php
index 1641266b0b1..3639d53665c 100644
--- a/webservice/xmlrpc/tests/xmlrpc_server_test.php
+++ b/webservice/xmlrpc/tests/xmlrpc_server_test.php
@@ -57,7 +57,7 @@ class xmlrpc_server_test extends advanced_testcase {
      */
     public function test_parse_request($input, $expectfunction, $expectparams) {
         $server = $this->getMockBuilder('\webservice_xmlrpc_server')
-                       ->setMethods(['fetch_input_content'])
+                       ->onlyMethods(['fetch_input_content'])
                        ->disableOriginalConstructor()
                        ->getMock();