Query/build/update_header_comments.php

<?php
declare(strict_types=1);

$file_patterns = [
    'src/**/*.php',
    'src/*.php',
    'tests/**/*.php',
    'tests/*.php',
    'Robofile.php'
];

if ( ! function_exists('glob_recursive'))
{
    // Does not support flag GLOB_BRACE

    function glob_recursive($pattern, $flags = 0)
    {
        $files = glob($pattern, $flags);

        foreach (glob(dirname($pattern) . '/*', GLOB_ONLYDIR | GLOB_NOSORT) as $dir)
        {
            $files = array_merge($files, glob_recursive($dir . '/' . basename($pattern), $flags));
        }

        return $files;
    }
}

function get_text_to_replace($tokens)
{
    $output = '';

    // Tokens have the follow structure if arrays:
    // [0] => token type constant
    // [1] => raw sytax parsed to that token
    // [2] => line number
    foreach($tokens as $token)
    {
        // Since we only care about opening docblocks,
        // bail out when we get to the namespace token
        if (is_array($token) && $token[0] === T_NAMESPACE)
        {
            break;
        }

        if (is_array($token))
        {
            $token = $token[1];
        }

        $output .= $token;
    }

    return $output;
}

function get_tokens($source)
{
    return token_get_all($source);
}

function replace_files(array $files, $template)
{
    print_r($files);
    foreach ($files as $file)
    {
        $source = file_get_contents($file);

        if (stripos($source, 'namespace') === FALSE)
        {
            continue;
        }

        $tokens = get_tokens($source);
        $text_to_replace = get_text_to_replace($tokens);

        $header = file_get_contents(__DIR__ . $template);
        $new_text = "<?php declare(strict_types=1);\n{$header}";

        $new_source = str_replace($text_to_replace, $new_text, $source);
        file_put_contents($file, $new_source);
    }
}

foreach ($file_patterns as $glob)
{
    $files = glob_recursive($glob);
    replace_files($files, '/header_comment.txt');
}

echo "Successfully updated headers \n";