undeclared class variables were throwing errors with PHP 8.2

question.php

@@ -37,6 +37,7 @@ class qtype_gapfill_question extends question_graded_automatically_with_countbac
      */
     public $answer;
 
+
     /**
      * Display draggables after the body of the question
      * @var boolean

tests/helper.php

@@ -33,13 +33,14 @@
  */
 class qtype_gapfill_test_helper extends question_test_helper {
 
+
     /**
      *  must be implemented or class made abstract
      *
      * @return string
      */
     public function get_test_questions() {
-        return array('catmat');
+        return ['catmat'];
     }
 
     /**
@@ -218,7 +219,7 @@ public static function make_question($questiontext = "The [cat] sat on the [mat]
             'qtype' => 'gapfill',
             'length' => '1',
             'stamp' => 'tjh238.vledev.open.ac.uk+100708154547+JrHygi',
-            'version' => 'tjh238.vledev.open.ac.uk+100708154548+a3zh8v',
+            'version' => 1,
             'hidden' => '0',
             'timecreated' => '1278603947',
             'timemodified' => '1278603947',
@@ -231,7 +232,6 @@ public static function make_question($questiontext = "The [cat] sat on the [mat]
         ];
 
         $question = $question->qtype->make_question($questiondata);
-        $question->gapstofill = count($answerwords);
         return $question;
     }
 

tests/question_test.php

@@ -43,6 +43,15 @@
  * @coversDefaultClass \question\type\gapfill\question
  */
 class question_test extends \advanced_testcase {
+
+    /** 
+    *
+    * @var qtype_gapfill $gapfill
+    * An instance of the question type
+    */
+    public $qtype;
+
+
     /**
      * Test value returned by questionid_column_name()
      *
@@ -255,6 +264,7 @@ public function test_is_same_response() {
     }
     public function setUp(): void {
         $this->qtype = \question_bank::get_qtype('gapfill');
+
     }
 
     protected function tearDown(): void {

tests/questiontype_test.php

@@ -39,6 +39,13 @@
  */
 class questiontype_test extends \advanced_testcase {
 
+    /** 
+    *
+    * @var qtype_gapfill $gapfill
+    * An instance of the question type
+    */
+    public $qtype;
+
     /**
      *  explained here https://docs.moodle.org/dev/Unit_test_API
      * @var array

tests/walkthrough_test.php

@@ -423,7 +423,8 @@ public function test_disableregex() {
             'disableregex' => 1,
         ];
         $gapfill = helper::make_question($questiontext, $options);
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $gapstofill = count($gapfill->answers);
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
 
         $this->check_current_state(\question_state::$todo);
         $this->check_current_mark(null);
@@ -467,8 +468,9 @@ public function test_interactive_discard_duplicates() {
         $submission = array('-submit' => 1, 'p1' => 'gold', 'p2' => 'silver', 'p3' => 'silver');
 
         $gapfill = helper::make_question( $questiontext, $options);
+        $gapstofill = count($gapfill->answers);
 
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
 
         // Check the initial state.
         $this->check_current_state(\question_state::$todo);
@@ -498,7 +500,9 @@ public function test_interactive_discard_duplicates() {
     public function test_no_duplicate_draggables() {
         $qtext = 'Bicycles have [wheels]. Cars have [wheels|engines].';
         $gapfill = helper::make_question($qtext);
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $gapstofill = count($gapfill->answers);
+
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
         // Confirm draggables are unique, i.e. wheels appears only once.
         $this->assertEquals(2, count($gapfill->allanswers));
     }
@@ -509,11 +513,13 @@ public function test_no_duplicate_draggables() {
      */
     public function test_get_letter_hints() {
         $gapfill = helper::make_question();
+        $gapstofill = count($gapfill->answers);
+
         $gapfill->hints = [
             new \question_hint(1, 'This is the first hint.', FORMAT_HTML),
             new \question_hint(2, 'This is the second hint.', FORMAT_HTML),
         ];
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
         $this->process_submission([ '-submit' => 1, 'p1' => 'cat', 'p2' => 'cat']);
         $this->process_submission(array('-tryagain' => 1));
         $qa = $this->quba->get_question_attempt($this->slot);
@@ -549,8 +555,9 @@ public function test_interactive_grade_for_blank() {
  [one] sat on the [two] [!!] ';
 
         $gapfill = helper::make_question( $questiontext);
+        $gapstofill = count($gapfill->answers);
 
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
 
         /* answer with duplicate values, only one of each duplicate should get a mark */
         /* save answer */
@@ -579,7 +586,7 @@ public function test_interactive_grade_for_blank() {
         $this->check_current_state(\question_state::$gradedright);
 
         /* start again but put a value in the field expecting a blank */
-        $this->start_attempt_at_question($gapfill, 'interactive', $gapfill->gapstofill);
+        $this->start_attempt_at_question($gapfill, 'interactive', $gapstofill);
         $submission = array('p1' => 'one', 'p2' => 'two', 'p3' => "three");
         $this->process_submission($submission);
         $this->check_step_count(2);
@@ -669,8 +676,9 @@ public function test_deferred_grade_for_blank() {
  [one] sat on the [two] [!!] ';
 
         $gapfill = helper::make_question( $questiontext);
+        $gapstofill = count($gapfill->answers);
 
-        $this->start_attempt_at_question($gapfill, 'deferredfeedback', $gapfill->gapstofill);
+        $this->start_attempt_at_question($gapfill, 'deferredfeedback', $gapstofill);
         /* A mark for a blank submission where the gap is [!!] */
         $submission = array('p1' => 'one', 'p2' => 'two', 'p3' => '');
 
@@ -704,7 +712,6 @@ public function test_immediatefeedback_with_correct() {
         $gapfill = helper::make_question();
         $maxmark = 2;
 
-        $gapfill->showanswers = true;
         $this->start_attempt_at_question($gapfill, 'immediatefeedback', $maxmark);
 
         // Check the initial state.