Development: Use default value if exercise has no plagiarism checks config

[jakubriegel]

Checklist

General

• This is a small issue that I tested locally and was confirmed by another developer on a test server.
• Language: I followed the guidelines for inclusive, diversity-sensitive, and appreciative language.
• I chose a title conforming to the naming conventions for pull requests.

Client

• Important: I implemented the changes with a very good performance, prevented too many (unnecessary) REST calls and made sure the UI is responsive, even with large data.
• I followed the coding and design guidelines.
• I added multiple integration tests (Jest) related to the features (with a high test coverage), while following the test guidelines.

Motivation and Context

Importing programming exercises from files created before merging of the continuous plagiarism control was not possible, because such files didn't contain plagiarism checks config. This caused the client to load the exercise creation form incorrectly.

Detected during tests of: #7624

Server part fixed in: #7640

Description

This PR adds a nullability check for exercise's plagiarism detection config before the exercise form is initialised. If exercise does not contain plagiarism detection config, the component inserts a default value into it.

Steps for Testing

Prerequisites:

• 1 Instructor
• 1 zip file with Programming Exercise without plagiarism detection config. You can use this one: Material-cr1-Sorting_Algorithms_Implementation-52-20231125-105137.zip

1. Go to course -> exercises.
2. Start programming exercise from the file provided.
3. Verify that the form displays correctly (including default plagiarism detection config).
4. Import the exercise.
5. Verify that the exercise was imported correctly.

Testserver States

Note

These badges show the state of the test servers.
Green = Currently available, Red = Currently locked

Review Progress

Performance Review

• I (as a reviewer) confirm that the client changes (in particular related to REST calls and UI responsiveness) are implemented with a very good performance
• I (as a reviewer) confirm that the server changes (in particular related to database calls) are implemented with a very good performance

Code Review

• Code Review 1
• Code Review 2

Manual Tests

• Test 1
• Test 2

Test Coverage

Class/File	Line Coverage	Confirmation (assert/expect)
exercise-update-plagiarism-component.ts	63% (testing just the new method)	✅

[tobias-lippert]

Code LGTM

[Strohgelaender]

Thanks for fixing this, but I already implemented #7657 with the same fix.

[JanaNF]

I tried to test this PR on TS2, Legcay_TS1, Legacy_TS2 and Legacy_TS11, and I always only saw the loading screen ("We'll be back soon"). I don't know what problems Artemis has right now but I had the same issue with other PRs too.

I will try to test this PR again tomorrow.

[sarpsahinalp]

Tested on ts2. Worked as expected

[JanaNF]

Manual tested on ts2. Worked as expected.

[jakubriegel]

Thanks for fixing this, but I already implemented #7657 with the same fix.

This is continuation of work started in #7640

[Strohgelaender]

code lgtm, let's merge that quickly.