Allow user_id to accept an array of IDs for WP_Comment_Query

[mordauk]

As the user who submitted ​this support ticket wanted, it seems perfectly reasonable to me that we should allow an array of user IDs to be passed to the user_id parameter of WP_Comment_Query in order to retrieve comments by multiple users.

I'd propose that the user_id allow either an integer or an array to be passed.

[mordauk]

Allow user_id to be passed as an array to WP_Comment_Query

[nacin]

Works for me. We should put a space between IN and (.

Would also be cool if a simple user test ended up in tests/phpunit/tests/comment/query.php.

[mordauk]

Sure thing, I'll upload a new patch in a few minutes.

[mordauk]

Refresh patch for spacing

[mordauk]

Basic unit tests for "user_id" parameter of get_comments()

[mordauk]

Patches updated. I don't have phpunit on this computer so the unit tests are untested (ha), but I think they will work.

I wasn't completely sure on the best way to write the tests for this one, so let me know if you'd prefer to see something different.

[mordauk]

Fixed failed assertions

[mordauk]

I've now tested and (after updating the patch) confirmed the unit tests pass now.

[mordauk]

More concise unit tests, thanks to markjaquith for his feedback

[nacin]

In 27258:

Allow user_id to be an array of IDs in WP_Comment_Query.

props mordauk.
fixes #27064.