Analyze implicit nullable parameter types

analyze_implicit_nullable_param_types.php

<?php declare(strict_types=1);
error_reporting(-1);
ini_set('memory_limit', -1);

require __DIR__ . '/vendor/autoload.php';

use PhpParser\Node;
use PhpParser\Node\Expr\ConstFetch;
use PhpParser\Node\NullableType;
use PhpParser\Node\Param;
use PhpParser\Node\UnionType;
use PhpParser\NodeVisitorAbstract;
use PhpParser\ParserFactory;

$visitor = new class extends NodeVisitorAbstract {
    public $path;
    public $code;

    public function enterNode(Node $node) {
        if (!$node instanceof Param) {
            return;
        }

        if (!$node->type || !$node->default) {
            return;
        }

        if ($node->default instanceof ConstFetch === false || $node->default->name->toLowerString() !== "null") {
            return;
        }

        if ($node->type instanceof NullableType) {
            return;
        }

        if ($node->type instanceof UnionType) {
            foreach ($node->type->types as $type) {
                if ($type instanceof NullableType) {
                    return;
                }
            }
        }

        if ($node->type instanceof Node\Identifier && $node->type->toLowerString() === "mixed") {
            return;
        }

        echo $this->path . ":" . $node->getStartLine() . "\n";
    }
};

$traverser = new PhpParser\NodeTraverser;

$traverser->addVisitor($visitor);

$it = new RecursiveIteratorIterator(
    new RecursiveDirectoryIterator('/usr/local/src/phpunit/src'),
    RecursiveIteratorIterator::LEAVES_ONLY
);

foreach ($it as $f) {
    $path = $f->getPathName();

    if (!preg_match('/\.php$/', $path)) {
        continue;
    }

    $code = file_get_contents($path);

    try {
        $stmts = (new ParserFactory)->createForHostVersion()->parse($code);
    } catch (PhpParser\Error $e) {
        echo $path . "\n";
        echo "Parse error: " . $e->getMessage() . "\n";
        continue;
    }

    $visitor->path = $path;
    $visitor->code = $code;

    $traverser->traverse($stmts);
}