Trac 59251 testing

check-disk-space.php

<?php
/**
 * Tests result of disk_free_space, used in /wp-admin/includes/class-wp-site-health.php.
 *
 * See https://core.trac.wordpress.org/ticket/59251.
 *
 * - Place file in /wp-content/mu-plugins/ and go to /wp-admin/. Result displayed as notice.
 * - Remove file when testing is complete.
 *
 * You can disable disk_free_space() by adding the following to php.ini and restarting PHP:
 *   disable_functions = disk_free_space
 */

add_action( 'admin_notices', 'test_disk_free_space' );

function test_disk_free_space() {
    $path            = WP_CONTENT_DIR . '/upgrade/';
    $available_space = function_exists( 'disk_free_space' ) ? @disk_free_space( $path ) : false;

    ?>
    <div class="notice notice-info is-dismissible">
        <h2>check-disk-space.php result:</h2>
        <pre><?php
            var_export( [
                'path'            => $path,
                'is_link'         => is_link( $path ),
                'function_exists' => function_exists( 'disk_free_space' ),
                'isInternal'      => function_exists( 'disk_free_space' ) ? ( new ReflectionFunction( 'disk_free_space' ) )->isInternal() : 'n/a',
                'available_space' => $available_space
            ] );
        ?></pre>
    </div>
    <?php
}

// Override disk_free_space when disabled in php.ini. Uncomment to test.
// if ( ! function_exists( 'disk_free_space' ) ) {
//     function disk_free_space() {
//         return 20 * MB_IN_BYTES - 1; // Triggers critical space warning.
//     }
// }