Error when removing a student from course

[igotdes]

Steps to Reproduce

So far, we haven't been able to reproduce, but this was reported in this forum thread:

https://wordpress.org/support/topic/fatal-error-array-cannot-be-empty-in-class-sensei-lesson-php383/#post-18233249

On our site when we remove a user from a course, here is the relevant stack trace:

class-sensei-utils.php(733): Sensei_Lesson->lesson_quiz_questions(‘10055172’)
class-sensei-utils.php(811): Sensei_Utils::sensei_get_quiz_questions(10055172)
class-sensei-utils.php(660): Sensei_Utils::sensei_delete_quiz_answers(10055172, 3405)
class-sensei-utils.php(706): Sensei_Utils::sensei_remove_user_from_lesson(10055171, 3405, true)
class-sensei-utils.php(2818): Sensei_Utils::sensei_remove_user_from_course(85579, 3405)

Seems like to remove the user from the course it wants to delete their quiz answers but to do that it gets the lesson_quiz_questions but in our case the $questions_array used in this code is empty:

$selected_questions = array_rand(
$questions_array,
$show_questions > $questions_count ? $questions_count : $show_questions
);```

And it errors out because it can’t randomize an empty array.

What I Expected

User should be able to remove students without errors.

What Happened Instead

User said they also installed Twenty Twenty-Five and Health Check. They then went to the Students area of the admin and Reset Progress on a user and it still caused a fatal error:

[15-Jan-2025 20:03:18 UTC] PHP Fatal error: Uncaught ValueError: array_rand(): Argument #1 ($array) cannot be empty in /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-lesson.php:3832
Stack trace: 0 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-lesson.php(3832): array_rand(Array, 0) 1 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-utils.php(733): Sensei_Lesson->lesson_quiz_questions(‘10055172’) 2 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-utils.php(811): Sensei_Utils::sensei_get_quiz_questions(10055172) 3 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-utils.php(660): Sensei_Utils::sensei_delete_quiz_answers(10055172, 3405) 4 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-utils.php(706): Sensei_Utils::sensei_remove_user_from_lesson(10055171, 3405, true) 5 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-utils.php(2818): Sensei_Utils::sensei_remove_user_from_course(85579, 3405) 6 /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/rest-api/class-sensei-rest-api-course-progress-controller.php(81): Sensei_Utils::reset_course_for_user(85579, 3405) 7 /wp-includes/rest-api/class-wp-rest-server.php(1292): Sensei_REST_API_Course_Progress_Controller->batch_delete_items(Object(WP_REST_Request)) 8 /wp-includes/rest-api/class-wp-rest-server.php(1125): WP_REST_Server->respond_to_request(Object(WP_REST_Request), ‘/sensei-interna…’, Array, NULL) 9 /wp-includes/rest-api/class-wp-rest-server.php(439): WP_REST_Server->dispatch(Object(WP_REST_Request)) 10 /wp-includes/rest-api.php(449): WP_REST_Server->serve_request(‘/sensei-interna…’) 11 /wp-includes/class-wp-hook.php(324): rest_api_loaded(Object(WP)) 12 /wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(”, Array) 13 /wp-includes/plugin.php(565): WP_Hook->do_action(Array) 14 /wp-includes/class-wp.php(418): do_action_ref_array(‘parse_request’, Array) 15 /wp-includes/class-wp.php(813): WP->parse_request(”) 16 /wp-includes/functions.php(1336): WP->main(”) 17 /wp-blog-header.php(16): wp() 18 /index.php(17): require(‘/Users/jon…..’) 19 {main}

thrown in /wp-content/plugins/woothemes-sensei/plugins/sensei-lms/includes/class-sensei-lesson.php on line 3832

PHP / WordPress / Sensei LMS version

Still waiting for more information from user.

Context / Source

@donnapep's comment on the forum ticket, #9288713-zen:

It would be good to open an issue for this one. Even if it's not reproducible, we can still add a check to ensure that the first parameter isn't empty before calling array_rand

[github-actions]

Support References

This comment is automatically generated. Please do not edit it.

• 9288713-zen