<?php

require 'vendor/autoload.php';

use Symfony\Component\Process\Process;

$reference = run_process();

echo "Output Reference:\n";
echo $reference;
echo "\n";

for ($i=0; $i < 100_000; $i++) {
    if ($i > 0 && $i % 80 === 0) {
        echo "\n";
    }
    echo '.';
    $output = run_process();
    if ($output !== $reference) {
        echo "\n!!Output changed!!\n";
        echo "New output:\n";
        echo "$output\n";
        exit(1);
    }
}

function run_process(){
    $process = new Process(['cat', __FILE__]);
    // If you comment the following line, the test become stable
    $process->setPty(true);
    $process->mustRun();

    return $process->getOutput();
}