Trash child notes when a top level note is trashed

[adamsilverstein]

Fixes WordPress/gutenberg#72862

Needs tests.

Trac ticket:

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Props adamsilverstein, desrosj, wildworks, mamaduka, karthickmurugan, jeffpaul, hanneslsm.

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[desrosj]

This looks like it will work well for trashing Notes, but only when the trash feature is enabled (setting EMPTY_TRASH_DAYS to a falsey value will bypass the trash and immediately delete comments and posts).

In that case, wp_delete_comment() is called very early in the function.

Instead of introducing a second function for this scenario, maybe making wp_trash_comment_children() function more generic. wp_handle_comment_children(), or something similar. Then if ( ! EMPTY_TRASH_DAYS ) { can be included to perform the desired action.

[desrosj]

Should we use wp_trash_note_children() or wp_trash_note_replies() instead here?

Thinking that this would make it more obvious that it's currently only intended for Notes. Down the road if we want this to be more general, wp_trash_note_children() could become a pass through to wp_trash_comment_children( $type = 'note' ), or whatever that ends up being.

If not, then the docblock should probably just say "a comment's children".

[desrosj]

What happens if some children are trashed but not all? I think that as is, the status would always be true. I think that's fine because the top-level comment was trashed, which is the ID passed to the function.

I don't think we need to address this now, but it will likely come up in the future.

[desrosj]

Suggested change

	* @since 6.9.1 Any child notes are deleted when deleting a note.
	* @since 6.9.0 Any child notes are deleted when deleting a note.

[desrosj]

Suggested change

	* @since 6.9.1
	* @since 6.9.0

[desrosj]

Could we add an assertion to confirm that replies are deleted with the top level note when it has been resolved? Just to cover more combinations.

[t-hamano]

I think there are two areas for improvement in the wp_trash_comment_children() function:

• It doesn't delete nested comments. This isn't a problem at the moment, but the notes might support nested replies in the future.
• It doesn't indicate whether the process was successful or not. Perhaps it should return a boolean value indicating success or failure, similar to wp_trash_comment?

I haven't actually tested it, but it should be something like this:

/**
 * Delete all of a comment's descendants.
 *
 * @since 6.9.0
 *
 * @param int $comment_id The comment ID.
 * @return bool True on success, false on failure.
 */
function wp_trash_comment_descendants( $comment_id ) {
	$comment = get_comment( $comment_id );
	if ( ! $comment ) {
		return false;
	}

	$comments = $comment->get_children(
		array(
			'format' => 'flat',
			'status' => 'all',
		)
	);

	$success = true;
	foreach ( $descendants as $child ) {
		if ( ! wp_trash_comment( $child->comment_ID ) ) {
			$success = false;
		}
	}

	return $success;
}