logger.php

<?php
function write_log( ...$data ) {
    if ( true === WP_DEBUG ) {

		$backtrace = debug_backtrace();

		$backtrace = array_shift( $backtrace );

		$output['backtrace'] = $backtrace['file'] . ':' . $backtrace['line'];
		foreach ( $data as $key => $value ) {
            $output['data' . ($key + 1)] = $value;
        }
		error_log( print_r( $output, true ) );
    }
}