MDL-77327 qtype_ddmarker: remove use of unnecessary undeclared field

Also:
  * Fix some incorrect punctuation in two strings.
  * Add a test to verify that this change does not cause a regression.
  * Improve some PHPdoc comments.

question/type/ddmarker/questiontype.php

@@ -65,11 +65,6 @@ class question_hint_ddmarker extends question_hint_with_parts {
         return new question_hint_ddmarker($row->id, $row->hint, $row->hintformat,
                 $row->shownumcorrect, $row->clearwrong, $row->options);
     }
-
-    public function adjust_display_options(question_display_options $options) {
-        parent::adjust_display_options($options);
-        $options->statewhichincorrect = $this->statewhichincorrect;
-    }
 }
 
 

question/type/ddmarker/tests/walkthrough_test.php

@@ -18,6 +18,7 @@ namespace qtype_ddmarker;
 
 use question_display_options;
 use question_hint_ddmarker;
+use question_pattern_expectation;
 use question_state;
 
 defined('MOODLE_INTERNAL') || die();
@@ -33,13 +34,17 @@ require_once($CFG->dirroot . '/question/type/ddmarker/tests/helper.php');
  * @package   qtype_ddmarker
  * @copyright 2012 The Open University
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers \qtype_ddmarker_question
+ * @covers \qtype_ddmarker_renderer
+ * @covers \question_hint_ddmarker
  */
 class walkthrough_test extends \qbehaviour_walkthrough_test_base {
 
     /**
      * Get an expectation that the output contains a marker.
-     * @param unknown $choice which choice.
+     *
-     * @param unknown $infinite whether there are infinitely many of that choice.
+     * @param int $choice which choice.
+     * @param bool $infinite whether there are infinitely many of that choice.
      * @return \question_contains_tag_with_attributes the expectation.
      */
     protected function get_contains_draggable_marker_home_expectation($choice, $infinite) {
@@ -55,8 +60,13 @@ class walkthrough_test extends \qbehaviour_walkthrough_test_base {
     }
 
     /**
-     * (non-PHPdoc)
+     * Get an expectation that the output contains a hidden input with certain name and optionally value.
-     * @see qbehaviour_walkthrough_test_base::get_contains_hidden_expectation()
+     *
+     * Like the parent method, but make it more specific to this question type.
+     *
+     * @param string $choiceno hidden field name.
+     * @param string|null $value if passed, this value will also be asserted.
+     * @return \question_contains_tag_with_attributes the expectation.
      */
     protected function get_contains_hidden_expectation($choiceno, $value = null) {
         $name = $this->quba->get_field_prefix($this->slot) .'c'. $choiceno;
@@ -716,4 +726,53 @@ class walkthrough_test extends \qbehaviour_walkthrough_test_base {
         $this->check_current_state(question_state::$gradedright);
         $this->check_current_mark(3);
     }
+
+    public function test_interactive_state_which_incorrect() {
+
+        // Create a drag-and-drop question.
+        $dd = \test_question_maker::make_question('ddmarker');
+        $dd->hints = [
+            new question_hint_ddmarker(23, 'This is the first hint.',
+                    FORMAT_MOODLE, false, true, true),
+        ];
+        $dd->shufflechoices = false;
+        $this->start_attempt_at_question($dd, 'interactive', 2);
+
+        // Check the initial state.
+        $this->check_current_state(question_state::$todo);
+        $this->check_current_mark(null);
+
+        $this->check_current_output(
+                $this->get_contains_marked_out_of_summary(),
+                $this->get_contains_draggable_marker_home_expectation(1, false),
+                $this->get_contains_draggable_marker_home_expectation(2, false),
+                $this->get_contains_draggable_marker_home_expectation(3, false),
+                $this->get_contains_hidden_expectation(1),
+                $this->get_contains_hidden_expectation(2),
+                $this->get_contains_hidden_expectation(3),
+                $this->get_contains_submit_button_expectation(true),
+                $this->get_does_not_contain_feedback_expectation(),
+                $this->get_tries_remaining_expectation(2),
+                $this->get_no_hint_visible_expectation());
+
+        // Save the a completely wrong answer.
+        $this->process_submission(
+                ['c1' => '100,150', 'c2' => '100,150', 'c3' => '50,50', '-submit' => 1]);
+
+        // Verify.
+        $this->check_current_state(question_state::$todo);
+        $this->check_current_mark(null);
+        $this->check_current_output(
+                $this->get_contains_marked_out_of_summary(),
+                $this->get_contains_draggable_marker_home_expectation(1, false),
+                $this->get_contains_draggable_marker_home_expectation(2, false),
+                $this->get_contains_draggable_marker_home_expectation(3, false),
+                $this->get_does_not_contain_submit_button_expectation(),
+                new question_pattern_expectation('~' . preg_quote(
+                        '<div class="wrongparts">The following markers have been placed in the wrong area: ' .
+                        '<span class="wrongpart">quick</span>, <span class="wrongpart">fox</span>, ' .
+                        '<span class="wrongpart">lazy</span>',
+                    '~') . '~'),
+                $this->get_contains_hint_expectation('This is the first hint'));
+    }
 }