diff --git a/backup/moodle2/backup_qtype_crossword_plugin.class.php b/backup/moodle2/backup_qtype_crossword_plugin.class.php
index 9cd398e..7eb2146 100644
--- a/backup/moodle2/backup_qtype_crossword_plugin.class.php
+++ b/backup/moodle2/backup_qtype_crossword_plugin.class.php
@@ -38,15 +38,17 @@ protected function define_question_plugin_structure(): backup_plugin_element {
         $plugin->add_child($pluginwrapper);
 
         // Now create the qtype own structures.
+        // phpcs:disable NormalizedArrays.Arrays.CommaAfterLast.MissingMultiLine
         $crossword = new backup_nested_element('crossword', ['id'], ['correctfeedback',
             'correctfeedbackformat', 'numrows', 'numcolumns', 'accentgradingtype', 'accentpenalty',
             'partiallycorrectfeedback', 'partiallycorrectfeedbackformat',
             'incorrectfeedback', 'incorrectfeedbackformat', 'shownumcorrect']);
+        // phpcs:enable
 
         // Define the elements.
         $words = new backup_nested_element('words');
-        $word = new backup_nested_element('word', ['id'], ['answer', 'clue', 'clueformat', 'orientation', 'startrow',
-            'startcolumn', 'feedback', 'feedbackformat']);
+        $word = new backup_nested_element('word', ['id'],
+            ['answer', 'clue', 'clueformat', 'orientation', 'startrow', 'startcolumn', 'feedback', 'feedbackformat']);
         $words->add_child($word);
         $pluginwrapper->add_child($crossword);
         $pluginwrapper->add_child($words);
@@ -61,7 +63,7 @@ protected function define_question_plugin_structure(): backup_plugin_element {
     public static function get_qtype_fileareas() {
         return [
             'clue' => 'qtype_crossword_words',
-            'feedback' => 'qtype_crossword_words'
+            'feedback' => 'qtype_crossword_words',
         ];
     }
 }
diff --git a/backup/moodle2/restore_qtype_crossword_plugin.class.php b/backup/moodle2/restore_qtype_crossword_plugin.class.php
index 057dd80..c8e01b8 100644
--- a/backup/moodle2/restore_qtype_crossword_plugin.class.php
+++ b/backup/moodle2/restore_qtype_crossword_plugin.class.php
@@ -33,7 +33,7 @@ protected function define_question_plugin_structure(): array {
         // We used get_recommended_name() so this works.
         $elements = [
             'qtype_crossword' => '/crossword',
-            'qtype_crossword_word' => '/words/word'
+            'qtype_crossword_word' => '/words/word',
         ];
 
         foreach ($elements as $elename => $path) {
diff --git a/classes/util.php b/classes/util.php
index 4e885d5..67ae068 100644
--- a/classes/util.php
+++ b/classes/util.php
@@ -15,8 +15,9 @@
 // along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
 
 namespace qtype_crossword;
+
 use Normalizer;
-use \qtype_crossword_question;
+
 /**
  * Static utilities.
  *
diff --git a/edit_crossword_form.php b/edit_crossword_form.php
index fbc8c56..3d3f088 100644
--- a/edit_crossword_form.php
+++ b/edit_crossword_form.php
@@ -81,7 +81,7 @@ protected function get_per_answer_fields($mform, $label, $gradeoptions,
             get_string('orientation', 'qtype_crossword'),
             [
                 get_string('across', 'qtype_crossword'),
-                get_string('down', 'qtype_crossword')
+                get_string('down', 'qtype_crossword'),
             ],
             null
         );
@@ -526,7 +526,12 @@ protected function find_conflicting_overlapping_letters(array $data, int $index,
      *
      * @return array The coordinate of the start and end of the word, [x1, y1, x2, y2].
      */
-    protected function calculate_word_coordinates(string $startrow, string $startcolumn, string $answer, string $orientation): array {
+    protected function calculate_word_coordinates(
+        string $startrow,
+        string $startcolumn,
+        string $answer,
+        string $orientation
+    ): array {
         $x1 = (int) $startcolumn;
         $y1 = (int) $startrow;
         // Get answer length.
diff --git a/renderer.php b/renderer.php
index 5793bba..8445c8f 100644
--- a/renderer.php
+++ b/renderer.php
@@ -39,7 +39,7 @@ public function formulation_and_controls(question_attempt $qa,
         $data = [];
         $orientationvalue = [
             get_string('across', 'qtype_crossword'),
-            get_string('down', 'qtype_crossword')
+            get_string('down', 'qtype_crossword'),
         ];
         $binddata = [
             'colsNum' => $question->numcolumns + 3,
@@ -47,7 +47,7 @@ public function formulation_and_controls(question_attempt $qa,
             'isPreview' => false,
             'title' => get_string('celltitle', 'qtype_crossword'),
             'orientation' => $orientationvalue,
-            'readonly' => false
+            'readonly' => false,
         ];
         $data['questiontext'] = $question->format_questiontext($qa);
         foreach ($question->answers as $key => $answer) {
@@ -91,7 +91,7 @@ public function formulation_and_controls(question_attempt $qa,
                 'startRow' => (int) $answer->startrow,
                 'startColumn' => (int) $answer->startcolumn,
                 'ignoreIndexes' => json_encode($ignoreindex),
-                'wordNumber' => $answer->answernumber
+                'wordNumber' => $answer->answernumber,
             ];
 
             if ($options->readonly) {
diff --git a/tests/answer_test.php b/tests/answer_test.php
index df65124..50b035b 100644
--- a/tests/answer_test.php
+++ b/tests/answer_test.php
@@ -33,10 +33,10 @@ class answer_test extends \advanced_testcase {
     /**
      * Test is_correct function.
      *
-     * @dataProvider test_is_correct_provider
+     * @dataProvider is_correct_test_provider
      * @covers \qtype_crossword_question::is_correct
      */
-    public function test_is_correct(array $answerdata) {
+    public function test_is_correct(array $answerdata): void {
         // Create a normal crossword question.
         $q = \test_question_maker::make_question('crossword', 'normal_with_hyphen_and_space');
         foreach ($q->answers as $key => $answer) {
@@ -47,17 +47,16 @@ public function test_is_correct(array $answerdata) {
     /**
      * Data provider for test_is_correct() test cases.
      *
-     * @coversNothing
      * @return array List of data sets (test cases)
      */
-    public function test_is_correct_provider(): array {
+    public static function is_correct_test_provider(): array {
         return [
             'Normal case' => [
-                ['TIM BERNERS-LEE', 'GORDON BROWN', 'DAVID ATTENBOROUGH']
+                ['TIM BERNERS-LEE', 'GORDON BROWN', 'DAVID ATTENBOROUGH'],
             ],
             'With Underscore' => [
-                ['TIM_BERNERS-LEE', 'GORDON_BROWN', 'DAVID_ATTENBOROUGH']
-            ]
+                ['TIM_BERNERS-LEE', 'GORDON_BROWN', 'DAVID_ATTENBOROUGH'],
+            ],
         ];
     }
 
@@ -66,7 +65,7 @@ public function test_is_correct_provider(): array {
      *
      * @covers \qtype_crossword_question::generate_answer_hint
      */
-    public function test_generate_answer_hint() {
+    public function test_generate_answer_hint(): void {
         // Create a normal crossword question.
         $q = \test_question_maker::make_question('crossword', 'normal_with_hyphen_and_space');
         $expecteddata = [
diff --git a/tests/backup_test.php b/tests/backup_test.php
index b906aa0..84e376c 100644
--- a/tests/backup_test.php
+++ b/tests/backup_test.php
@@ -75,10 +75,9 @@ protected function restore_crossword_question_backup_file_to_course_shortname(
     /**
      * Data provider for test_cw_backup_data().
      *
-     * @coversNothing
      * @return array
      */
-    public function test_cw_backup_data_provider(): array {
+    public static function backup_test_data_provider(): array {
 
         return [
             'before upgrade feedback column' => [
@@ -92,22 +91,22 @@ public function test_cw_backup_data_provider(): array {
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'BRAZIL'
+                        'answer' => 'BRAZIL',
                     ],
                     [
                         'clue' => 'Eiffel Tower is located in?',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'PARIS'
+                        'answer' => 'PARIS',
                     ],
                     [
                         'clue' => 'Where is the Leaning Tower of Pisa?',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'ITALY'
-                    ]
+                        'answer' => 'ITALY',
+                    ],
                 ],
                 'version' => 4,
             ],
@@ -122,22 +121,22 @@ public function test_cw_backup_data_provider(): array {
                         'clueformat' => FORMAT_HTML,
                         'feedback' => '<p dir="ltr" style="text-align: left;">You are correct.</p>',
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'BRAZIL'
+                        'answer' => 'BRAZIL',
                     ],
                     [
                         'clue' => '<p>Eiffel Tower is located in?</p>',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => '<p dir="ltr" style="text-align: left;">You are correct.<br></p>',
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'PARIS'
+                        'answer' => 'PARIS',
                     ],
                     [
                         'clue' => '<p>Where is the Leaning Tower of Pisa?</p>',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => '<p dir="ltr" style="text-align: left;">You are correct.<br></p>',
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'ITALY'
-                    ]
+                        'answer' => 'ITALY',
+                    ],
                 ],
                 'version' => 4,
             ],
@@ -152,22 +151,22 @@ public function test_cw_backup_data_provider(): array {
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'BRAZIL'
+                        'answer' => 'BRAZIL',
                     ],
                     [
                         'clue' => 'Eiffel Tower is located in?',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'PARIS'
+                        'answer' => 'PARIS',
                     ],
                     [
                         'clue' => 'Where is the Leaning Tower of Pisa?',
                         'clueformat' => FORMAT_HTML,
                         'feedback' => null,
                         'feedbackformat' => FORMAT_HTML,
-                        'answer' => 'ITALY'
-                    ]
+                        'answer' => 'ITALY',
+                    ],
                 ],
                 'version' => 3,
             ],
@@ -194,7 +193,7 @@ public function test_cw_backup_data_provider(): array {
     /**
      * Test crossword old backup data
      *
-     * @dataProvider test_cw_backup_data_provider
+     * @dataProvider backup_test_data_provider
      * @param string $filename file name of the backup file.
      * @param string $coursefullname course full name.
      * @param string $courseshortname course short name
@@ -250,10 +249,10 @@ public function test_cw_backup_data(string $filename, string $coursefullname, st
     /**
      * Test backup/restore question type crossword.
      *
-     * @dataProvider test_backup_restore_course_with_cw_provider
+     * @dataProvider backup_restore_course_with_cw_test_provider
      * @param string $crosswordtemplate Crossword template.
      */
-    public function test_backup_restore_course_with_cw(string $crosswordtemplate) {
+    public function test_backup_restore_course_with_cw(string $crosswordtemplate): void {
         global $DB;
         $this->resetAfterTest();
         $this->setAdminUser();
@@ -298,10 +297,9 @@ public function test_backup_restore_course_with_cw(string $crosswordtemplate) {
     /**
      * Data provider for test_backup_restore_course_with_cw().
      *
-     * @coversNothing
      * @return array
      */
-    public function test_backup_restore_course_with_cw_provider(): array {
+    public static function backup_restore_course_with_cw_test_provider(): array {
 
         return [
             'Normal crossword' => [
diff --git a/tests/form_test.php b/tests/form_test.php
index b58e1db..27e67f4 100644
--- a/tests/form_test.php
+++ b/tests/form_test.php
@@ -46,173 +46,127 @@ class form_test extends \advanced_testcase {
      *
      * @return array List of data sets (test cases)
      */
-    public function form_validation_testcases(): array {
+    public static function form_validation_testcases(): array {
         return [
             'Normal case' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'BRAZIL', 'PARIS', 'ITALY'
-                    ],
+                    'answer' => ['BRAZIL', 'PARIS', 'ITALY'],
                     'clue' => [
                         ['text' => 'where is the Christ the Redeemer statue located in?', 'format' => FORMAT_HTML],
                         ['text' => 'Eiffel Tower is located in?', 'format' => FORMAT_HTML],
-                        ['text' => 'Where is the Leaning Tower of Pisa?', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 1, 0
-                    ],
-                    'startrow' => [
-                        1, 0, 3
+                        ['text' => 'Where is the Leaning Tower of Pisa?', 'format' => FORMAT_HTML],
                     ],
-                    'startcolumn' => [
-                        0, 2, 2
-                    ],
-                ], []
+                    'orientation' => [0, 1, 0],
+                    'startrow' => [1, 0, 3],
+                    'startcolumn' => [0, 2, 2],
+                ],
+                [],
             ],
             'The letter at the intersection of two words do not match' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'AAA', 'BBB', 'CCC'
-                    ],
+                    'answer' => ['AAA', 'BBB', 'CCC'],
                     'clue' => [
                         ['text' => 'Clue A', 'format' => FORMAT_HTML],
                         ['text' => 'Clue B', 'format' => FORMAT_HTML],
-                        ['text' => 'Clue C', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 0, 0
-                    ],
-                    'startrow' => [
-                        0, 0, 0
-                    ],
-                    'startcolumn' => [
-                        0, 0, 0
+                        ['text' => 'Clue C', 'format' => FORMAT_HTML],
                     ],
+                    'orientation' => [0, 0, 0],
+                    'startrow' => [0, 0, 0],
+                    'startcolumn' => [0, 0, 0],
                 ],
                 [
                     'answer[1]' => get_string('wrongintersection', 'qtype_crossword'),
-                    'answer[2]' => get_string('wrongintersection', 'qtype_crossword')
-                ]
+                    'answer[2]' => get_string('wrongintersection', 'qtype_crossword'),
+                ],
             ],
             'Requires at least 1 word' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        '', '', ''
-                    ],
+                    'answer' => ['', '', ''],
                     'clue' => [
                         ['text' => '', 'format' => FORMAT_HTML],
                         ['text' => '', 'format' => FORMAT_HTML],
-                        ['text' => '', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 0, 0
-                    ],
-                    'startrow' => [
-                        0, 0, 0
-                    ],
-                    'startcolumn' => [
-                        0, 0, 0
+                        ['text' => '', 'format' => FORMAT_HTML],
                     ],
-                ], ['answer[0]' => get_string('notenoughwords', 'qtype_crossword', 1)]
+                    'orientation' => [0, 0, 0],
+                    'startrow' => [0, 0, 0],
+                    'startcolumn' => [0, 0, 0],
+                ],
+                [
+                    'answer[0]' => get_string('notenoughwords', 'qtype_crossword', 1),
+                ],
             ],
             'The word start or end position is outside the defined grid size' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'Toolongtext', 'BBB', 'CCC'
-                    ],
+                    'answer' => ['Toolongtext', 'BBB', 'CCC'],
                     'clue' => [
                         ['text' => 'Clue A', 'format' => FORMAT_HTML],
                         ['text' => 'Clue B', 'format' => FORMAT_HTML],
-                        ['text' => 'Clue C', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 0, 0
-                    ],
-                    'startrow' => [
-                        0, 1, 2
-                    ],
-                    'startcolumn' => [
-                        0, 0, 0
+                        ['text' => 'Clue C', 'format' => FORMAT_HTML],
                     ],
-                ], ['answer[0]' => get_string('overflowposition', 'qtype_crossword')]
+                    'orientation' => [0, 0, 0],
+                    'startrow' => [0, 1, 2],
+                    'startcolumn' => [0, 0, 0],
+                ],
+                [
+                    'answer[0]' => get_string('overflowposition', 'qtype_crossword'),
+                ],
             ],
             'The answer must be alphanumeric characters only' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'Speci@al char*', 'BBB', 'CCC'
-                    ],
+                    'answer' => ['Speci@al char*', 'BBB', 'CCC'],
                     'clue' => [
                         ['text' => 'Clue A', 'format' => FORMAT_HTML],
                         ['text' => 'Clue B', 'format' => FORMAT_HTML],
-                        ['text' => 'Clue C', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 0, 0
-                    ],
-                    'startrow' => [
-                        0, 1, 2
+                        ['text' => 'Clue C', 'format' => FORMAT_HTML],
                     ],
-                    'startcolumn' => [
-                        0, 0, 0
-                    ],
-                ], ['answer[0]' => get_string('mustbealphanumeric', 'qtype_crossword')]
+                    'orientation' => [0, 0, 0],
+                    'startrow' => [0, 1, 2],
+                    'startcolumn' => [0, 0, 0],
+                ],
+                [
+                    'answer[0]' => get_string('mustbealphanumeric', 'qtype_crossword'),
+                ],
             ],
             'The word must have both clues and answers' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'AAA', '', 'CCC'
-                    ],
+                    'answer' => ['AAA', '', 'CCC'],
                     'clue' => [
                         ['text' => '', 'format' => FORMAT_HTML],
                         ['text' => 'Clue B', 'format' => FORMAT_HTML],
-                        ['text' => 'Clue C', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 0, 0
-                    ],
-                    'startrow' => [
-                        0, 1, 2
-                    ],
-                    'startcolumn' => [
-                        0, 0, 0
+                        ['text' => 'Clue C', 'format' => FORMAT_HTML],
                     ],
+                    'orientation' => [0, 0, 0],
+                    'startrow' => [0, 1, 2],
+                    'startcolumn' => [0, 0, 0],
                 ],
                 [
                     'answer[1]' => get_string('pleaseenterclueandanswer', 'qtype_crossword', 2),
                     'clue[0]' => get_string('pleaseenterclueandanswer', 'qtype_crossword', 1),
-                ]
+                ],
             ],
             'Ensure a unique answer number for each orientation.' => [
                 [
                     'noanswers' => 3,
-                    'answer' => [
-                        'ABC', 'ACB', 'ABC'
-                    ],
+                    'answer' => ['ABC', 'ACB', 'ABC'],
                     'clue' => [
                         ['text' => 'Clue A', 'format' => FORMAT_HTML],
                         ['text' => 'Clue B', 'format' => FORMAT_HTML],
-                        ['text' => 'Clue C', 'format' => FORMAT_HTML]
-                    ],
-                    'orientation' => [
-                        0, 1, 0
-                    ],
-                    'startrow' => [
-                        0, 0, 0
-                    ],
-                    'startcolumn' => [
-                        0, 0, 0
+                        ['text' => 'Clue C', 'format' => FORMAT_HTML],
                     ],
+                    'orientation' => [0, 1, 0],
+                    'startrow' => [0, 0, 0],
+                    'startcolumn' => [0, 0, 0],
                 ],
                 [
                     'answer[2]' => get_string('wrongoverlappingwords', 'qtype_crossword', 'ABC'),
-                ]
-            ]
+                ],
+            ],
         ];
     }
 
@@ -265,20 +219,20 @@ public function test_form_validation(array $sampledata, array $expectederror): v
             'name' => 'Test combined with varnumeric',
             'questiontext' => [
                 'text' => 'Test crossword qtype',
-                'format' => 1
+                'format' => 1,
             ],
             'generalfeedback' => [
                 'text' => '',
-                'format' => 1
+                'format' => 1,
             ],
             'partiallycorrectfeedback' => [
                 'text' => 'Your answer is partially correct.',
-                'format' => 1
+                'format' => 1,
             ],
             'shownumcorrect' => 1,
             'incorrectfeedback' => [
                 'text' => 'Your answer is incorrect.',
-                'format' => 1
+                'format' => 1,
             ],
             'numcolumns' => 5,
             'numrows' => 7,
@@ -311,7 +265,7 @@ public function test_form_validation(array $sampledata, array $expectederror): v
      *
      * @dataProvider generate_alphabet_list_testcases
      */
-    public function test_generate_alphabet_list(array $option, array $expected) {
+    public function test_generate_alphabet_list(array $option, array $expected): void {
         list ($mform) = $this->prepare_test_data();
         list ($start, $end) = $option;
         $method = new \ReflectionMethod(\qtype_crossword_edit_form::class,
@@ -327,19 +281,20 @@ public function test_generate_alphabet_list(array $option, array $expected) {
      * @return array
      */
     public function generate_alphabet_list_testcases(): array {
-
+        // phpcs:disable NormalizedArrays.Arrays.CommaAfterLast.MissingMultiLine
         return [
             'Alphabet list from 1 to 26' => [
                 [0, 26],
                 ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
-                    'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
+                    'T', 'U', 'V', 'W', 'X', 'Y', 'Z'],
             ],
             'Alphabet list from 1 to 30' => [
                 [0, 30],
                 ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
-                    'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'AA', 'AB', 'AC', 'AD']
+                    'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'AA', 'AB', 'AC', 'AD'],
             ],
         ];
+        // phpcs:enable
     }
 
     /**
@@ -348,7 +303,7 @@ public function generate_alphabet_list_testcases(): array {
      * @param array $data Data from provider.
      * @dataProvider validate_answer_testcases
      */
-    public function test_validate_answer(array $data) {
+    public function test_validate_answer(array $data): void {
         list ($mform) = $this->prepare_test_data();
         $method = new \ReflectionMethod(\qtype_crossword_edit_form::class,
             'validate_answer');
diff --git a/tests/helper.php b/tests/helper.php
index b935863..2e5156f 100644
--- a/tests/helper.php
+++ b/tests/helper.php
@@ -43,10 +43,12 @@ class qtype_crossword_test_helper extends question_test_helper {
      * @return array The test question array.
      */
     public function get_test_questions(): array {
+        // phpcs:disable NormalizedArrays.Arrays.CommaAfterLast.MissingMultiLine
         return ['normal', 'unicode', 'different_codepoint', 'sampleimage',
             'clear_incorrect_response', 'normal_with_hyphen_and_space',
             'not_accept_wrong_accents', 'accept_wrong_accents_but_subtract_point',
             'accept_wrong_accents_but_not_subtract_point'];
+        // phpcs:enable
     }
 
     /**
@@ -153,15 +155,15 @@ public function get_crossword_question_form_data_normal() {
         $fromform->clue = [
             [
                 'text' => 'Eiffel Tower is located in?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'where is the Christ the Redeemer statue located in?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'Where is the Leaning Tower of Pisa?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->orientation = [1, 0, 0];
@@ -177,24 +179,30 @@ public function get_crossword_question_form_data_normal() {
     /**
      * Makes a normal crossword question with a sample image in question text.
      *
-     * @return qtype_crossword_question
+     * @return stdClass
      */
-    public function get_crossword_question_form_data_sampleimage() {
+    public function get_crossword_question_form_data_sampleimage(): stdClass {
         $fromform = $this->get_crossword_question_form_data_normal();
-        $fromform->correctfeedback = ['text' => 'Correct feedback <img src="@@PLUGINFILE@@/correctfbimg.jpg" />',
-            'format' => FORMAT_HTML];
-        $fromform->partiallycorrectfeedback = ['text' => 'Partially correct feedback. <img src="@@PLUGINFILE@@/partialfbimg.jpg"',
-            'format' => FORMAT_HTML];
-        $fromform->incorrectfeedback = ['text' => 'Incorrect feedback. <img src="@@PLUGINFILE@@/incorrectfbimg.jpg"',
-            'format' => FORMAT_HTML];
+        $fromform->correctfeedback = [
+            'text' => 'Correct feedback <img src="@@PLUGINFILE@@/correctfbimg.jpg" />',
+            'format' => FORMAT_HTML,
+        ];
+        $fromform->partiallycorrectfeedback = [
+            'text' => 'Partially correct feedback. <img src="@@PLUGINFILE@@/partialfbimg.jpg"',
+            'format' => FORMAT_HTML,
+        ];
+        $fromform->incorrectfeedback = [
+            'text' => 'Incorrect feedback. <img src="@@PLUGINFILE@@/incorrectfbimg.jpg"',
+            'format' => FORMAT_HTML,
+        ];
         $fromform->questiontext = [
             'text' => 'Cross word question text with sample image <img src="@@PLUGINFILE@@/questiontextimg.jpg" />',
-            'format' => FORMAT_HTML
+            'format' => FORMAT_HTML,
         ];
         $fromform->feedback = [
             [
                 'text' => 'where is the Christ the Redeemer statue located in? <img src="@@PLUGINFILE@@/feedback.jpg" />',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->clue[0]['text'] = 'Eiffel Tower is located in?' .
@@ -299,15 +307,15 @@ public function get_crossword_question_form_data_unicode() {
         $fromform->clue = [
             [
                 'text' => '线索 1',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => '线索 2',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => '线索 3',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->orientation = [1, 0, 1];
@@ -380,7 +388,7 @@ public function make_crossword_question_different_codepoint() {
                 $answer->startcolumn,
                 $answer->feedback,
                 $answer->feedbackformat,
-                $answer->answernumber
+                $answer->answernumber,
             );
         }
         return $cw;
@@ -402,11 +410,11 @@ public function get_crossword_question_form_data_different_codepoint() {
         $fromform->clue = [
             [
                 'text' => 'Answer contains letter é has codepoint \u00e9',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'Answer contains letter é has codepoint \u0065\u0301',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->orientation = [0, 1];
@@ -432,7 +440,7 @@ public function make_crossword_question_clear_incorrect_response() {
     /**
      * Get a crossword with the clear incorrect response options.
      *
-     * @return qtype_crossword_question
+     * @return stdClass
      */
     public function get_crossword_question_form_data_clear_incorrect_response() {
         $fromform = $this->get_crossword_question_form_data_normal();
@@ -443,7 +451,7 @@ public function get_crossword_question_form_data_clear_incorrect_response() {
      * Retrieve the context object.
      * @param \context $context the current context.
      *
-     * @return object The context object.
+     * @return question_edit_contexts The context object.
      */
     public static function question_edit_contexts(\context $context): object {
         if (class_exists('\core_question\local\bank\question_edit_contexts')) {
@@ -501,7 +509,7 @@ public function make_crossword_question_normal_with_hyphen_and_space() {
                 'orientation' => 1,
                 'feedback' => '',
                 'feedbackformat' => FORMAT_HTML,
-                'answernumber' => 1
+                'answernumber' => 1,
             ],
             (object) [
                 'id' => 2,
@@ -514,7 +522,7 @@ public function make_crossword_question_normal_with_hyphen_and_space() {
                 'orientation' => 1,
                 'feedback' => '',
                 'feedbackformat' => FORMAT_HTML,
-                'answernumber' => 2
+                'answernumber' => 2,
             ],
             (object) [
                 'id' => 3,
@@ -527,7 +535,7 @@ public function make_crossword_question_normal_with_hyphen_and_space() {
                 'orientation' => 0,
                 'feedback' => '',
                 'feedbackformat' => FORMAT_HTML,
-                'answernumber' => 3
+                'answernumber' => 3,
             ],
         ];
 
@@ -564,15 +572,15 @@ public function get_crossword_question_form_data_normal_with_hyphen_and_space()
         $fromform->clue = [
             [
                 'text' => 'Engineer, computer scientist and inventor of the World Wide Web?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'Former Prime Minister of the United Kingdom?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'British broadcaster and naturalist, famous for his voice-overs of nature programmes?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->orientation = [1, 1, 0];
@@ -678,11 +686,11 @@ public function get_crossword_question_form_data_not_accept_wrong_accents() {
         $fromform->clue = [
             [
                 'text' => 'Des accompagnements à base de foie animal ?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
             [
                 'text' => 'Appareil utilisé pour passer des appels ?',
-                'format' => FORMAT_HTML
+                'format' => FORMAT_HTML,
             ],
         ];
         $fromform->orientation = [0, 1];
diff --git a/tests/question_test.php b/tests/question_test.php
index ba28e9e..754e2d8 100644
--- a/tests/question_test.php
+++ b/tests/question_test.php
@@ -38,7 +38,7 @@ class question_test extends \advanced_testcase {
      *
      * @covers \qtype_crossword_question::is_complete_response
      */
-    public function test_is_complete_response() {
+    public function test_is_complete_response(): void {
         $question = \test_question_maker::make_question('crossword');
 
         $this->assertFalse($question->is_complete_response([]));
@@ -62,36 +62,35 @@ public function test_clear_wrong_from_response(array $responses, array $expected
     /**
      * Data provider for the test_clear_wrong_from_response.
      *
-     * @coversNothing
      * @return array
      */
-    public function clear_wrong_from_response_provider(): array {
+    public static function clear_wrong_from_response_provider(): array {
 
         return [
             'Empty answer' => [
                 [],
-                []
+                [],
             ],
             'Partial correct answers' => [
                 ['sub0' => 'PARI', 'sub1' => 'BRZIL', 'sub2' => 'ITALY'],
-                ['sub2' => 'ITALY', 'sub0' => '', 'sub1' => '']
+                ['sub2' => 'ITALY', 'sub0' => '', 'sub1' => ''],
             ],
             'Correct answers is not in ordered' => [
                 ['sub1' => 'BRAZIL', 'sub0' => 'PARIS', 'sub2' => 'ITALY'],
-                ['sub1' => 'BRAZIL', 'sub0' => 'PARIS', 'sub2' => 'ITALY']
+                ['sub1' => 'BRAZIL', 'sub0' => 'PARIS', 'sub2' => 'ITALY'],
             ],
             'Correct answers is in ordered' => [
                 ['sub0' => 'PARIS', 'sub1' => 'BRAZIL', 'sub2' => 'ITALY'],
-                ['sub0' => 'PARIS', 'sub1' => 'BRAZIL', 'sub2' => 'ITALY']
+                ['sub0' => 'PARIS', 'sub1' => 'BRAZIL', 'sub2' => 'ITALY'],
             ],
             'Not completed answers' => [
                 ['sub1' => 'BRAZIL', 'sub2' => 'ITALY'],
-                ['sub1' => 'BRAZIL', 'sub2' => 'ITALY']
+                ['sub1' => 'BRAZIL', 'sub2' => 'ITALY'],
             ],
             'Not completed and incorrect answer' => [
                 ['sub1' => 'BRAZIL', 'sub2' => 'ITALI'],
-                ['sub1' => 'BRAZIL', 'sub2' => '']
-            ]
+                ['sub1' => 'BRAZIL', 'sub2' => ''],
+            ],
         ];
     }
 
@@ -112,21 +111,20 @@ public function test_clear_wrong_from_response_with_accent(string $template, arr
     /**
      * Data provider for the test_clear_wrong_from_response.
      *
-     * @coversNothing
      * @return array
      */
-    public function clear_wrong_from_response_with_accent(): array {
+    public static function clear_wrong_from_response_with_accent(): array {
 
         return [
             'Ignore accent' => [
                 'accept_wrong_accents_but_not_subtract_point',
                 ['sub0' => 'PATE', 'sub1' => 'TELEPHONE'],
-                ['sub0' => 'PATE', 'sub1' => 'TELEPHONE']
+                ['sub0' => 'PATE', 'sub1' => 'TELEPHONE'],
             ],
             'Partial correct answers with accent' => [
                 'accept_wrong_accents_but_subtract_point',
                 ['sub0' => 'PÂTÉ', 'sub1' => 'TELEPHONE'],
-                ['sub0' => 'PÂTÉ', 'sub1' => '']
+                ['sub0' => 'PÂTÉ', 'sub1' => ''],
             ],
         ];
     }
@@ -136,7 +134,7 @@ public function clear_wrong_from_response_with_accent(): array {
      *
      * @covers \qtype_crossword_question::is_gradable_response
      */
-    public function test_is_gradable_response() {
+    public function test_is_gradable_response(): void {
         $question = \test_question_maker::make_question('crossword');
 
         $this->assertFalse($question->is_gradable_response([]));
@@ -151,7 +149,7 @@ public function test_is_gradable_response() {
      * @covers \qtype_crossword_question::grade_response
      * @dataProvider grading_provider
      */
-    public function test_grading(array $answeroptions) {
+    public function test_grading(array $answeroptions): void {
         $question = \test_question_maker::make_question('crossword', 'not_accept_wrong_accents');
         $question->accentgradingtype = $answeroptions['options']['accentgradingtype'];
         $question->accentpenalty = $answeroptions['options']['accentpenalty'];
@@ -167,7 +165,7 @@ public function test_grading(array $answeroptions) {
      *
      * @covers \qtype_crossword_question::get_correct_response
      */
-    public function test_get_correct_response() {
+    public function test_get_correct_response(): void {
         $question = \test_question_maker::make_question('crossword');
         $this->assertEquals(['sub0' => 'PARIS', 'sub1' => 'BRAZIL', 'sub2' => 'ITALY'], $question->get_correct_response());
     }
@@ -181,7 +179,7 @@ public function test_get_correct_response() {
      * @covers \qtype_crossword_question::filter_answers
      * @dataProvider remove_blank_words_from_response_testcases
      */
-    public function test_filter_answers(array $response, int $expectednumberofwords) {
+    public function test_filter_answers(array $response, int $expectednumberofwords): void {
         $this->resetAfterTest();
         $crossword = new \qtype_crossword_question();
         $method = new \ReflectionMethod(\qtype_crossword_question::class, 'remove_blank_words_from_response');
@@ -194,21 +192,21 @@ public function test_filter_answers(array $response, int $expectednumberofwords)
      *
      * @return array
      */
-    public function remove_blank_words_from_response_testcases(): array {
+    public static function remove_blank_words_from_response_testcases(): array {
 
         return [
             'answer_valid_list' => [
                 ['sub0' => 'BRAZIL', 'sub1' => 'PARIS', 'sub2' => 'ITALY'],
-                3
+                3,
             ],
             'answer_invalid_list_with_underscore' => [
                 ['sub0' => 'BRAZIL', 'sub1' => '____', 'sub2' => 'IT_LY'],
-                2
+                2,
             ],
             'answer_invalid_list_with_empty_string' => [
                 ['sub0' => '', 'sub1' => '', 'sub2' => ''],
-                0
-            ]
+                0,
+            ],
         ];
     }
 
@@ -219,7 +217,7 @@ public function remove_blank_words_from_response_testcases(): array {
      * @covers \qtype_crossword_question::get_num_parts_right
      * @dataProvider grading_provider
      */
-    public function test_get_num_parts_right(array $answeroptions) {
+    public function test_get_num_parts_right(array $answeroptions): void {
         $this->resetAfterTest();
         $question = \test_question_maker::make_question('crossword', 'not_accept_wrong_accents');
         $question->start_attempt(new question_attempt_step(), 1);
@@ -239,7 +237,7 @@ public function test_get_num_parts_right(array $answeroptions) {
      * @covers \qtype_crossword_question::get_num_parts_partial
      * @dataProvider grading_provider
      */
-    public function test_get_num_parts_partial(array $answeroptions) {
+    public function test_get_num_parts_partial(array $answeroptions): void {
         $this->resetAfterTest();
         $question = \test_question_maker::make_question('crossword', 'not_accept_wrong_accents');
         $question->start_attempt(new question_attempt_step(), 1);
@@ -258,7 +256,7 @@ public function test_get_num_parts_partial(array $answeroptions) {
      * @covers \qtype_crossword_question::is_full_fraction
      * @dataProvider grading_provider
      */
-    public function is_full_fraction(array $answeroptions) {
+    public function test_is_full_fraction(array $answeroptions): void {
         $this->resetAfterTest();
         $question = \test_question_maker::make_question('crossword', 'not_accept_wrong_accents');
         $question->start_attempt(new question_attempt_step(), 1);
@@ -273,10 +271,9 @@ public function is_full_fraction(array $answeroptions) {
     /**
      * Data provider for the get_num_parts_right and grading test.
      *
-     * @coversNothing
      * @return array
      */
-    public function grading_provider(): array {
+    public static function grading_provider(): array {
 
         return [
             'Answer options not accepts wrong accented' => [
@@ -401,10 +398,9 @@ public function test_calculate_fraction_for_answer(array $inputoptions, array $e
     /**
      * Data provider for test_calculate_fraction_for_answer_for_answer() test cases.
      *
-     * @coversNothing
      * @return array List of data sets (test cases).
      */
-    public function test_calculate_fraction_for_answer_provider(): array {
+    public static function test_calculate_fraction_for_answer_provider(): array {
         return [
             'Wrong accents are not accepted and the answers are absolutely correct.' => [
                 'inputoptions' => [
diff --git a/tests/question_type_test.php b/tests/question_type_test.php
index c69074b..b2aecf3 100644
--- a/tests/question_type_test.php
+++ b/tests/question_type_test.php
@@ -100,7 +100,7 @@ public function test_export_to_xml(): void {
                                 'startcolumn' => 0,
                                 'feedback' => '<b>Feedback data</b>',
                                 'feedbackformat' => FORMAT_PLAIN,
-                            ] ,
+                            ],
                             (object)[
                                 'id' => 2,
                                 'questionid' => 8862,
@@ -110,7 +110,7 @@ public function test_export_to_xml(): void {
                                 'orientation' => 0,
                                 'startrow' => 1,
                                 'startcolumn' => 0,
-                            ] ,
+                            ],
                             (object)[
                                 'id' => 2,
                                 'questionid' => 8862,
@@ -120,8 +120,8 @@ public function test_export_to_xml(): void {
                                 'orientation' => 0,
                                 'startrow' => 2,
                                 'startcolumn' => 0,
-                            ] ,
-                        ]
+                            ],
+                        ],
                     ],
                 'hints' => [
                     (object)[
@@ -130,7 +130,7 @@ public function test_export_to_xml(): void {
                         'hint' => 'Hint 1',
                         'hintformat' => FORMAT_HTML,
                         'shownumcorrect' => 0,
-                        'clearwrong' => 0
+                        'clearwrong' => 0,
                     ],
                     (object)[
                         'id' => 2,
@@ -138,14 +138,14 @@ public function test_export_to_xml(): void {
                         'hint' => 'Hint 2',
                         'hintformat' => FORMAT_HTML,
                         'shownumcorrect' => 1,
-                        'clearwrong' => 1
+                        'clearwrong' => 1,
                     ],
                 ],
                 'returnurl' => '/question/edit.php?courseid=35&cat=1299%2C2005&recurse=1&showhidden=1&qbshowtext=0',
                 'makecopy' => 0,
                 'courseid' => '35',
                 'inpopup' => 0,
-                'contextid' => 91
+                'contextid' => 91,
             ];
 
         $exporter = new \qformat_xml();
diff --git a/tests/util_test.php b/tests/util_test.php
index 3eac019..57f465d 100644
--- a/tests/util_test.php
+++ b/tests/util_test.php
@@ -42,7 +42,7 @@ class util_test extends \qbehaviour_walkthrough_test_base {
     /**
      * Test safe_normalize function.
      *
-     * @dataProvider test_safe_normalize_provider
+     * @dataProvider safe_normalize_test_provider
      * @covers \qtype_crossword\util::safe_normalize
      *
      * @param string $string1 The first string need to compare.
@@ -57,26 +57,25 @@ public function test_safe_normalize(string $string1, string $string2): void {
     /**
      * Data provider for test_safe_normalize() test cases.
      *
-     * @coversNothing
      * @return array List of data sets (test cases)
      */
-    public function test_safe_normalize_provider(): array {
+    public static function safe_normalize_test_provider(): array {
         return [
             'Normal case' => [
                 'Hanoi',
-                'Hanoi'
+                'Hanoi',
             ],
             'Same character but different representation code' => [
                 'Amélie',
-                'Amélie'
-            ]
+                'Amélie',
+            ],
         ];
     }
 
     /**
      * Test remove_accent function.
      *
-     * @dataProvider test_remove_accent_provider
+     * @dataProvider remove_accent_test_provider
      * @covers \qtype_crossword\util::remove_accent
      *
      * @param string $containaccent The string contain accent characters.
@@ -90,26 +89,25 @@ public function test_remove_accent(string $containaccent, string $missingaccent)
     /**
      * Data provider for test_remove_accent() test cases.
      *
-     * @coversNothing
      * @return array List of data sets (test cases)
      */
-    public function test_remove_accent_provider(): array {
+    public static function remove_accent_test_provider(): array {
         return [
             'Normal case' => [
                 'Hanoi',
-                'Hanoi'
+                'Hanoi',
             ],
             'One wrong accent' => [
                 'médecin',
-                'medecin'
+                'medecin',
             ],
             'Two wrong accent' => [
                 'pâté',
-                'pate'
+                'pate',
             ],
             'Three wrong accent' => [
                 'téléphoné',
-                'telephone'
+                'telephone',
             ],
         ];
     }
@@ -134,7 +132,7 @@ public function test_remove_break_characters(string $text, string $expected): vo
      * @coversNothing
      * @return array List of data sets (test cases)
      */
-    public function remove_break_characters_testcases(): array {
+    public static function remove_break_characters_testcases(): array {
         return [
             'Text with space' => [
                 'Los angeles',
@@ -196,7 +194,7 @@ public function test_rearrange_answers(array $orderedanswers): void {
                 'startcolumn' => 0,
                 'feedback' => 'Feedback',
                 'feedbackformat' => 1,
-            ]
+            ],
         ];
 
         // We will order the answer based on startcolumn and startrow. So, the order list will be:
@@ -237,10 +235,9 @@ public function test_update_answer_list(array $orderedanswers): void {
     /**
      * Data provider return ordered answer list.
      *
-     * @coversNothing
      * @return array Ordered answer list.
      */
-    public function ordered_answers_provider(): array {
+    public static function ordered_answers_provider(): array {
         return [
             'Ordered answer list' => [
                 [
@@ -276,9 +273,9 @@ public function ordered_answers_provider(): array {
                         'startcolumn' => 1,
                         'feedback' => 'Feedback',
                         'feedbackformat' => 1,
-                    ]
-                ]
-            ]
+                    ],
+                ],
+            ],
         ];
     }
 }