wp-admin/includes/class-wp-site-health.php:903Tests if required PHP modules are installed on the host.
arrayOne hook fires while WP_Site_Health::get_test_php_extensions() runs, in this order:
Filters the array representing all the modules we wish to test for.
public function get_test_php_extensions() { $result = array( 'label' => __( 'Required and recommended modules are installed' ), 'status' => 'good', 'badge' => array( 'label' => __( 'Performance' ), 'color' => 'blue', ), 'description' => sprintf( '<p>%s</p><p>%s</p>', __( 'PHP modules perform most of the tasks on the server that make your site run. Any changes to these must be made by your server administrator.' ), sprintf( /* translators: 1: Link to the hosting group page about recommended PHP modules. 2: Additional link attributes. 3: Accessibility text. */ __( 'The WordPress Hosting Team maintains a list of those modules, both recommended and required, in <a href="%1$s" %2$s>the team handbook%3$s</a>.' ), /* translators: Localized team handbook, if one exists. */ esc_url( __( 'https://make.wordpress.org/hosting/handbook/handbook/server-environment/#php-extensions' ) ), 'target="_blank"', sprintf( '<span class="screen-reader-text"> %s</span><span aria-hidden="true" class="dashicons dashicons-external"></span>', /* translators: Hidden accessibility text. */ __( '(opens in a new tab)' ) ) ) ), 'actions' => '', 'test' => 'php_extensions', ); $modules = array( 'curl' => array( 'function' => 'curl_version', 'required' => false, ), 'dom' => array( 'class' => 'DOMNode', 'required' => false, ), 'exif' => array( 'function' => 'exif_read_data', 'required' => false, ), 'fileinfo' => array( 'function' => 'finfo_file', 'required' => false, ), 'hash' => array( 'function' => 'hash', 'required' => true, ), 'imagick' => array( 'extension' => 'imagick', 'required' => false, ), 'json' => array( 'function' => 'json_last_error', 'required' => true, ), 'mbstring' => array( 'function' => 'mb_check_encoding', 'required' => false, ), 'mysqli' => array( 'function' => 'mysqli_connect', 'required' => false, ), // Sodium was introduced in PHP 7.2, but the extension may not be enabled. 'libsodium' => array( 'constant' => 'SODIUM_LIBRARY_VERSION', 'required' => false, 'php_bundled_version' => '7.2.0', ), 'openssl' => array( 'function' => 'openssl_encrypt', 'required' => false, ), 'pcre' => array( 'function' => 'preg_match', 'required' => false, ), 'mod_xml' => array(Introduced in 5.2.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/class-wp-site-health.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.