Implement changes made necessary by the fix for MDL-83541

[mjleblanc]

After fix for MDL-83541, code runner questions are always duplicated when duplicating a quiz in a course or doing a backup and restore in same course.

[raveiga]

Yes, I have the same problem with latest version Moodle 4.5.3+

When a teacher duplicates a quiz with questions related with Coderunner it duplicates all the questions in database.

[tlock]

Also, the unit tests are failing:

mod_quiz\backup\repeated_restore_test::test_restore_quiz_with_duplicate_questions with data set "coderunner" ('coderunner', 'sqr')
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'3'
+'4'

mod/quiz/tests/backup/repeated_restore_test.php:423

mod_quiz\backup\repeated_restore_test::test_restore_quiz_with_edited_questions with data set "coderunner" ('coderunner', 'sqr')
Failed asserting that 1 matches expected '3'.

mod/quiz/tests/backup/repeated_restore_test.php:490

[trampgeek]

Yeah, well. Sorry guys, but I've been somewhat blindsided by this sudden change to the question API in the middle of a teaching semester when I have 1000 students in my course. My CodeRunner development time is over the summer break (Southern Hemisphere time), not in the middle of a course.

I have pushed to the development branch code that results in CodeRunner questions now passing Moodle's repeated_restore_test but questions are still being duplicated when you duplicate a quiz. I clearly need to dig deeper but time is very limited right now so I'm afraid you'll have to wait a bit. Unless someone else chooses to fix it.

[tlock]

🎉

[tlock]

Some feedback, this unit test fails for us on v5.2.1.

Moodle: 4.5.3+ (Build: 20250328)
Php: 8.3.16, pgsql: 15.8 (Postgres.app), OS: Darwin 24.3.0 arm64
PHPUnit 9.6.18 by Sebastian Bergmann and contributors.

1. qtype_coderunner\restore_test::test_restore
   Undefined array key "testtype"

/usr/local/git/moodle2/moodle5/question/type/coderunner/backup/moodle2/restore_qtype_coderunner_plugin.class.php:115

(
[id] => 27
[testcode] =>
[expected] => Good
[useasexample] => 0
[display] => SHOW
[hiderestiffail] => 0
[mark] => 1.000
[stdin] =>
[extra] => nfa
epsilon
)

2. qtype_coderunner\restore_test::test_restore_from_v3_0_0
   Undefined array key "testtype"

/usr/local/git/moodle2/moodle5/question/type/coderunner/backup/moodle2/restore_qtype_coderunner_plugin.class.php:115

Array
(
[id] => 12
[testcode] =>
[expected] => Good
[useasexample] => 0
[display] => SHOW
[hiderestiffail] => 0
[mark] => 1.000
[stdin] =>
[extra] => nfa
epsilon
)

testtype not defined in: loadtesting_pseudocourse_backup.mbz

Fixed:

-                $testcase->$field = $record[$field];
+                $testcase->$field = $record[$field] ?? '';

[CyrilWendl]

It seems like the duplication issue is still not resolved, so I propose to keep this issue open if possible. Thank you!

[trampgeek]

Certainly it should be kept open. I didn't intend to close it, sorry.

[ngandrass]

I tried to find the exact cause of the duplication issue but haven't gotten my head around it yet. I used the latest development branch.

What I did find:

• Only prototypes seem to be duplicated
• The final question (indicated by prototypetype = 0) is not being duplicated
• Having a quiz containing a single coderunner question: When duplicating this quiz multiple times, all previously duplicated prototypes are again duplicated. This results in: 1, 2, 4, 8, 16, ... prototypes after each quiz duplication.
• Some question options are conditionally casted to other types or set to null under certain conditions. This will likely impact the question hash generation during duplicate detection.
• tests/helper.php does not seem to contain any used prototyped question. Therefore mod/quiz/tests/backup/repeated_restore_test.php most likely does not run into this issue.
• Excluding the noninherited_fields from the question data object generated by remove_excluded_question_data() does not fix the issue
• A try to replicate the conditional type casts from get_question_options() and its decedents failed due to missing knowledge of the underlying data structures on my side.

Sadly I have to move on to other topics right now but I wanted to at least report on the stuff I tried and found out. Hope this helps anyone :)

[CyrilWendl]

I tried to find the exact cause of the duplication issue but haven't gotten my head around it yet. I used the latest development branch.

What I did find:

• Only prototypes seem to be duplicated
• The final question (indicated by prototypetype = 0) is not being duplicated
• Having a quiz containing a single coderunner question: When duplicating this quiz multiple times, all previously duplicated prototypes are again duplicated. This results in: 1, 2, 4, 8, 16, ... prototypes after each quiz duplication.
• Some question options are conditionally casted to other types or set to null under certain conditions. This will likely impact the question hash generation during duplicate detection.
• tests/helper.php does not seem to contain any used prototyped question. Therefore mod/quiz/tests/backup/repeated_restore_test.php most likely does not run into this issue.
• Excluding the noninherited_fields from the question data object generated by remove_excluded_question_data() does not fix the issue
• A try to replicate the conditional type casts from get_question_options() and its decedents failed due to missing knowledge of the underlying data structures on my side.

Sadly I have to move on to other topics right now but I wanted to at least report on the stuff I tried and found out. Hope this helps anyone :)

Thank you so much. May I ask, for the Moodle user community not familiar with the internals, what a prototype is? And is there a way to somehow fix this issue by marking a question as non-prototype within the Moodle UI? Do you know of any other ways how users could circumvent the issue?

Thank you and kind regards

[timhunt]

I just want to make sure we have a link here to the key documentation:

• Question restore developer docs
• Second half of this developer meeting, where Mark explains it.

[trampgeek]

Thanks for looking into this @ngandrass . I had a quick look myself yesterday.

As you've spotted, the problem lies with CodeRunner's use of prototype questions. In CodeRunner a runnable question comes in two parts: a prototype that defines the type of CodeRunner question (the programming language, how it behaves and is graded etc) and the actual question. Prior to being run, the actual question is merged with the prototype. Loosely you can think of the prototype as a class definition and the question as an instance of the class.

The algorithm being used in this "fix", is to compare a raw question imported from the backup with an existing loaded-and-ready-to-run version. But in CodeRunner these are two different things, because the latter has had all the prototype attributes merged into it. This merging takes place in the following line in my get_question_options() function

$this->set_inherited_fields($options, $question->prototype);

If I comment out that line, the duplication problem goes away. (Well, it goes away in my current simple test, anyway). If I had some way of knowing that the call was coming from the module-duplicate-and-backup-restore processor I could simply skip that line. But I can't see a way to do that, except by inspecting the runtime stack. Which is just too evil, even for me.

Today I'll see if I can remove all those prototype attributes again in the remove_excluded_question_data method. It's not going to be pretty, but it's the best idea I have at present.

[*** EDIT *** Big discovery. During the call to get_guestion_options() the question has been tagged with the attribute 'export_process'. Testing for this attribute and, if found, disabling the setting of inherited fields seems to largely solve the problem. Just some edge cases to deal with :-) ]