simulate-offset-bug.php

<?php
/**
 * Plugin Name: Simulate Comment Meta Box Offset Bug
 * Description: Demonstrates the "Show more comments" offset bug in the Comments meta box
 *              using a custom comment type, without altering core filters.
 * Version:     1.0
 * Author:      Test Automation Team
 */

/**
 * Ensure the 'post' post type supports comments.
 */
add_action( 'init', function () {
	add_post_type_support( 'post', 'comments' );
} );

/**
 * Add the native WordPress comments meta box to the 'post' post type.
 */
add_action( 'add_meta_boxes', function () {
	add_meta_box(
		'commentsdiv',
		__( 'Comments' ),
		'post_comment_meta_box',
		'post',
		'normal',
		'core'
	);
} );

/**
 * On plugin activation, create a post with 16 custom comments of type 'custom_note'.
 *
 * WordPress core does not add the 'comment' class for custom comment types,
 * which causes the "Show more comments" offset logic in post.js to break.
 */
register_activation_hook( __FILE__, function () {
	$post_id = wp_insert_post( [
		'post_title'   => 'Custom Comment Type Test',
		'post_content' => 'This post contains 16 comments of a custom comment type (custom_note).',
		'post_status'  => 'publish',
		'post_type'    => 'post',
	] );

	if ( ! $post_id || is_wp_error( $post_id ) ) {
		return;
	}

	// Insert 16 approved comments of type 'custom_note'.
	for ( $i = 1; $i <= 16; $i++ ) {
		wp_insert_comment( [
			'comment_post_ID'      => $post_id,
			'comment_author'       => 'Tester',
			'comment_author_email' => 'tester@example.com',
			'comment_content'      => "Custom Comment #{$i}",
			'comment_type'         => 'custom_note',
			'comment_approved'     => 1,
		] );
	}
} );