wordpress-develop/tests/phpunit/tests/comment/walker.php

<?php

/**
 * @group comment
 */
class Tests_Comment_Walker extends WP_UnitTestCase {

	function setUp() {
		parent::setUp();

		$this->post_id = self::factory()->post->create();
	}

	/**
	 * @ticket 14041
	 */
	function test_has_children() {
		$comment_parent = self::factory()->comment->create( array( 'comment_post_ID' => $this->post_id ) );
		$comment_child  = self::factory()->comment->create(
			array(
				'comment_post_ID' => $this->post_id,
				'comment_parent'  => $comment_parent,
			)
		);
		$comment_parent = get_comment( $comment_parent );
		$comment_child  = get_comment( $comment_child );

		$comment_walker   = new Walker_Comment();
		$comment_callback = new Comment_Callback_Test( $this, $comment_walker );

		wp_list_comments(
			array(
				'callback' => array( $comment_callback, 'comment' ),
				'walker'   => $comment_walker,
				'echo'     => false,
			),
			array( $comment_parent, $comment_child )
		);
		wp_list_comments(
			array(
				'callback' => array( $comment_callback, 'comment' ),
				'walker'   => $comment_walker,
				'echo'     => false,
			),
			array( $comment_child, $comment_parent )
		);
	}
}

class Comment_Callback_Test {
	public function __construct( Tests_Comment_Walker $test_walker, Walker_Comment $walker ) {
		$this->test_walker = $test_walker;
		$this->walker      = $walker;
	}

	public function comment( $comment, $args, $depth ) {
		if ( 1 === $depth ) {
			$this->test_walker->assertTrue( $this->walker->has_children );
			$this->test_walker->assertTrue( $args['has_children'] );  // Back compat.
		} elseif ( 2 === $depth ) {
			$this->test_walker->assertFalse( $this->walker->has_children );
			$this->test_walker->assertFalse( $args['has_children'] ); // Back compat.
		}
	}
}