Test #21989

test_21989.php

<?php

/**
 * Plugin Name: Test #21989
 * Description: Tests <a href="https://core.trac.w.org/ticket/21989">#21989</a>.
 * Author:      WordPress Core Contributors
 * Author URI:  https://make.wordpress.org/core
 * License:     GPLv2 or later
 * Version:     1.0.0
 */

class Test_21989 {
	const OPTION      = 'test_21989';
	const BASE_VALUE  = 'a_string';
	const APPEND      = '_1';
	private $expected = null;
	private $notice   = '';

	public function __construct() {
		$this->expected = self::BASE_VALUE . self::APPEND;

		// Comment this line to test `update_option()` only (option must exist).
		delete_option( self::OPTION );

		add_action( 'admin_init', array( $this, 'init' ) );
	}

	public function init() {
		add_filter( 'sanitize_option_' . self::OPTION, array( $this, 'sanitize_option' ) );
		add_filter( 'pre_update_option_' . self::OPTION, array( $this, 'pre_update_option_option' ) );
		add_filter( 'pre_update_option', array( $this, 'pre_update_option' ), 10, 2 );

		add_action( 'add_option_' . self::OPTION, array( $this, 'add_option' ), 999, 2 );
		add_action( 'update_option', array( $this, 'update_option' ), 999, 3 );

		update_option( self::OPTION, 'a_string' );

		add_action( 'admin_notices', array( $this, 'admin_notices' ) );
	}

	public function sanitize_option( $value ) {
		$new_value     = $value . self::APPEND;
		$this->notice .= '<p>Before <code>sanitize_option</code>: ' . $value . '</p>';
		$this->notice .= '<p>After <code>sanitize_option</code>: ' . $new_value . '</p>';

		return $new_value;
	}

	public function pre_update_option_option( $value ) {
		$is_expected   = $this->expected === $value ? 'Yes' : 'No';
		$this->notice .= '<p><code>pre_update_option_test_{$option}</code> Still "' . $this->expected . '"? ' . $is_expected . '</p>';

		return $value;
	}

	public function pre_update_option( $value, $option ) {
		if ( self::OPTION !== $option ) {
			return $value;
		}

		$is_expected   = $this->expected === $value ? 'Yes' : 'No';
		$this->notice .= '<p><code>pre_update_option</code> Still "' . $this->expected . '"? ' . $is_expected . '</p>';

		return $value;
	}

	public function add_option( $option, $value ) {
		if ( self::OPTION !== $option ) {
			return;
		}

		$this->notice .= '<p><code>add_option()</code>: ' . $value . '</p>';
	}

	public function update_option( $option, $old_value, $value ) {
		if ( self::OPTION !== $option ) {
			return;
		}

		$this->notice .= '<p><code>update_option()</code>: ' . $value . '</p>';
	}

	public function admin_notices() {
		echo '<div class="notice notice-info"><p>' . $this->notice . '</p></div>';
	}
}

new Test_21989();