MDL-82633 mod_quiz: re-factor visibility check for overrides.

mod/quiz/classes/local/override_manager.php

@@ -447,6 +447,22 @@ class override_manager {
         }
     }
 
+    /**
+     * Determine whether user can view a given override record
+     *
+     * @param \stdClass $override
+     * @param \stdClass $course
+     * @param \cm_info $cm
+     * @return bool
+     */
+    public function can_view_override(\stdClass $override, \stdClass $course, \cm_info $cm): bool {
+        if ($override->groupid) {
+            return groups_group_visible($override->groupid, $course, $cm);
+        } else {
+            return groups_user_groups_visible($course, $override->userid, $cm);
+        }
+    }
+
     /**
      * Builds common event data
      *

mod/quiz/overridedelete.php

@@ -44,15 +44,8 @@ require_login($course, false, $cm);
 
 // Check the user has the required capabilities to modify an override.
 $manager->require_manage_capability();
-
-if ($override->groupid) {
-    if (!groups_group_visible($override->groupid, $course, $cm)) {
-        throw new \moodle_exception('invalidoverrideid', 'quiz');
-    }
-} else {
-    if (!groups_user_groups_visible($course, $override->userid, $cm)) {
-        throw new \moodle_exception('invalidoverrideid', 'quiz');
-    }
+if (!$manager->can_view_override($override, $course, $cm)) {
+    throw new \moodle_exception('invalidoverrideid', 'quiz');
 }
 
 $url = new moodle_url('/mod/quiz/overridedelete.php', ['id' => $override->id]);

mod/quiz/overrideedit.php

@@ -72,14 +72,8 @@ if ($overrideid) {
     // Editing an override.
     $data = clone $override;
 
-    if ($override->groupid) {
-        if (!groups_group_visible($override->groupid, $course, $cm)) {
-            throw new \moodle_exception('invalidoverrideid', 'quiz');
-        }
-    } else {
-        if (!groups_user_groups_visible($course, $override->userid, $cm)) {
-            throw new \moodle_exception('invalidoverrideid', 'quiz');
-        }
+    if (!$manager->can_view_override($override, $course, $cm)) {
+        throw new \moodle_exception('invalidoverrideid', 'quiz');
     }
 } else {
     // Creating a new override.

mod/quiz/tests/local/override_manager_test.php

@@ -46,7 +46,7 @@ final class override_manager_test extends \advanced_testcase {
      * @return array containing quiz object and course
      */
     private function create_quiz_and_course(): array {
-        $course = $this->getDataGenerator()->create_course(['groupmode' => SEPARATEGROUPS]);
+        $course = $this->getDataGenerator()->create_course(['groupmode' => SEPARATEGROUPS, 'groupmodeforce' => 1]);
         $quizparams = array_merge(self::TEST_QUIZ_SETTINGS, ['course' => $course->id]);
         $quiz = $this->getDataGenerator()->create_module('quiz', $quizparams);
         $quizobj = quiz_settings::create($quiz->id);
@@ -123,6 +123,89 @@ final class override_manager_test extends \advanced_testcase {
         ];
     }
 
+    /**
+     * Data provider for {@see test_can_view_override}
+     *
+     * @return array[]
+     */
+    public static function can_view_override_provider(): array {
+        return [
+            ['admin', true, true, true, true],
+            ['teacher', true, false, true, false],
+        ];
+    }
+
+    /**
+     * Test whether user can view given override
+     *
+     * @param string $currentuser
+     * @param bool $grouponeview
+     * @param bool $grouptwoview
+     * @param bool $studentoneview
+     * @param bool $studenttwoview
+     *
+     * @dataProvider can_view_override_provider
+     */
+    public function test_can_view_override(
+        string $currentuser,
+        bool $grouponeview,
+        bool $grouptwoview,
+        bool $studentoneview,
+        bool $studenttwoview,
+    ): void {
+        global $DB;
+
+        $this->resetAfterTest();
+
+        [$quizobj, $course] = $this->create_quiz_and_course();
+
+        // Teacher cannot view all groups.
+        $roleid = $DB->get_field('role', 'id', ['shortname' => 'editingteacher']);
+        assign_capability('moodle/site:accessallgroups', CAP_PROHIBIT, $roleid, $quizobj->get_context()->id);
+
+        // Group one will contain our teacher and another student.
+        $groupone = $this->getDataGenerator()->create_group(['courseid' => $course->id]);
+        $teacher = $this->getDataGenerator()->create_and_enrol($course, 'editingteacher', ['username' => 'teacher']);
+        $this->getDataGenerator()->create_group_member(['groupid' => $groupone->id, 'userid' => $teacher->id]);
+        $studentone = $this->getDataGenerator()->create_and_enrol($course);
+        $this->getDataGenerator()->create_group_member(['groupid' => $groupone->id, 'userid' => $studentone->id]);
+
+        // Group two will contain a solitary student.
+        $grouptwo = $this->getDataGenerator()->create_group(['courseid' => $course->id]);
+        $studenttwo = $this->getDataGenerator()->create_and_enrol($course);
+        $this->getDataGenerator()->create_group_member(['groupid' => $grouptwo->id, 'userid' => $studenttwo->id]);
+
+        $user = \core_user::get_user_by_username($currentuser);
+        $this->setUser($user);
+
+        /** @var override_manager $manager */
+        $manager = $quizobj->get_override_manager();
+
+        $this->assertEquals($grouponeview, $manager->can_view_override(
+            (object) ['groupid' => $groupone->id, 'userid' => null],
+            $course,
+            $quizobj->get_cm(),
+        ));
+
+        $this->assertEquals($grouptwoview, $manager->can_view_override(
+            (object) ['groupid' => $grouptwo->id, 'userid' => null],
+            $course,
+            $quizobj->get_cm(),
+        ));
+
+        $this->assertEquals($studentoneview, $manager->can_view_override(
+            (object) ['userid' => $studentone->id, 'groupid' => null],
+            $course,
+            $quizobj->get_cm(),
+        ));
+
+        $this->assertEquals($studenttwoview, $manager->can_view_override(
+            (object) ['userid' => $studenttwo->id, 'groupid' => null],
+            $course,
+            $quizobj->get_cm(),
+        ));
+    }
+
     /**
      * Provides values to test_save_and_get_override
      *