Find composer updates without version constraints

composer-check.php

<?php
require_once __DIR__ . '/vendor/autoload.php';

$lock = json_decode(file_get_contents(__DIR__ . '/composer.lock'));
$json = json_decode(file_get_contents(__DIR__ . '/composer.json'), true)['require'];

$client = new \GuzzleHttp\Client();

foreach ($lock->packages as $package) {
    $current = json_decode($client->get('https://packagist.org/packages/' . $package->name . '.json')->getBody(), true)['package']['versions'];
    foreach ($current as $version => $data) {
        if(preg_match('~^v?[0-9.]+$~', $version)) {
            if($version > $package->version) {
                echo $package->name . ": $version > " . $package->version . (isset($json[$package->name]) ?: '' . ' (dependency)') . "\n";
            }
            break;
        }
    }
}