PHP pretty print objects and arrays in a log file

debug-log.php

function debug( $message, $label = '', $log_file = 'debug.log' ) {
	if ( is_bool( $message ) ) {
		$message = $message ? 'true' : 'false';
	} else if ( is_array( $message ) || is_object( $message ) ) {
		$message = json_encode(
			$message,
			JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES
		);
	}

	if ( ! empty( $label ) ) {
		$label = ' - ' . $label;
	}

	error_log(
		date( 'Y-m-d H:i:s' ) . $label . ': ' . $message ."\n",
		3,
		$_SERVER['DOCUMENT_ROOT'] . $log_file
	);
}