Notes from task breakdown:
Subtasks:

• Add PATCH item descriptions route to OAS doc
• Create PatchItemDescriptions happy path (empty edit summary)
• Handle edit metadata (bot flag, tags)
• Authorization
• Generate the expected edit summary - language codes are to be sorted alphabetically
• Validate user input (the patch document, item id, edit metadata)
• Handle errors that occur while patching the descriptions (test condition, addressing fields that don't exist, ...)
• Validate the patched descriptions (similar to PatchedLabelsValidator)
  • handles all cases where the patched JSON structure cannot be deserialized into a valid description TermList (empty description, description too long, description containing invalid characters, language code)
  • Collision detection (checking that no other item has the same combination of label and description in any changed language)
  • Check that no changed description is now the same as the label in any changed language
• Respond 404/409 if item not found or redirected
• Use the usual middlewares
• Add OpenAPI validation test
• Mark as production ready

Change 961835 had a related patch set uploaded (by Ollie Shotton; author: Ollie Shotton):

[mediawiki/extensions/Wikibase@master] REST: Add metadata to PatchItemDescriptionsResponse

https://gerrit.wikimedia.org/r/961835

Change 961835 merged by jenkins-bot:

[mediawiki/extensions/Wikibase@master] REST: Add metadata to PatchItemDescriptionsResponse

https://gerrit.wikimedia.org/r/961835

Open questions to this after product verification:

After changes a description is invalid (not allowed characters used): What does this entail exactly? I added a word in the Devanagari script and used a Cyrillic alphabet under "/en" and both worked perfectly. This shouldn't work as far as I understand

After changes an invalid language code is used: Also not sure how I can test this?

@Ifrahkhanyaree_WMDE Regarding testing After changes an invalid language code is used it can be tested by the following patch request:

{
	"patch": [
		{
			"op": "add",
			"path": "/e3",
			"value": "there is no language code like e3"
		}
	],
	"comment": "my first patch request"
}

And regarding After changes a description is invalid (not allowed characters used), as far as I understand, it's related to using a wrong characters inside the description that is modified, for example, to use a number instead of a text, or if the description contained special characters like \t or \n, something like this:

{
	"patch": [
		{
			"op": "add",
			"path": "/en",
			"value": "invalid \n description"
		}
	],
	"comment": "my first patch request"
}

But using a valid text in a different language is valid AFAIK, because I don't remember that we check for such cases.

I was doing it with replace and completely forgot there's other operations of course ¯\_(ツ)_/¯

Hmm, I'll move the ticket to Done but I'll ask the question about using different scripts in the daily on Wed.

Thanks!

@Ifrahkhanyaree_WMDE Wikibase does not validate the script used in labels/descriptions/aliases. There might be cases when that wouldn't be desired. And while it would make sense in some obvious cases it might not be a trivial mechanism to create. In any case, adding this kind of validation is something outside of API's responsibilities, i.e. it should be a policy/restriction/safety that Wikibase generally employs.

Yes yes of course, it's something WD would have to do but I was just wondering why the validation didn't exist. I can only imagine that it must be complex