Analyze implicit nullable parameter types

analyze_implicit_nullable_param_types.php

<?php

error_reporting(E_ALL);
ini_set("memory_limit", "6G");

use PhpParser\Lexer\Emulative;
use PhpParser\Node;
use PhpParser\Node\Expr\ConstFetch;
use PhpParser\Node\NullableType;
use PhpParser\Node\Param;
use PhpParser\Node\UnionType;
use PhpParser\NodeVisitorAbstract;

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

$lexer = new Emulative([
    'usedAttributes' => [
        'comments', 'startLine', 'endLine',
        'startFilePos', 'endFilePos',
    ]
]);
$parser = new PhpParser\Parser\Php7($lexer);

$visitor = new class (__DIR__ . '/sources/') extends NodeVisitorAbstract {
    public $path;
    public $code;
    public int $totalImplicitNullableParamTypes = 0;
    public array $projectsUsingImplicitNullableParamTypes = [];
    private string $sourceDir;

    public function __construct(string $sourceDir)
    {
        $this->sourceDir = $sourceDir;
    }

    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;
        }

        $this->totalImplicitNullableParamTypes++;

        $projectDirs = explode("/", str_replace($this->sourceDir, "", $this->path), 3);
        $projectDir = $projectDirs[0] . "/" . $projectDirs[1];

        if (!isset($this->projectsUsingImplicitNullableParamTypes[$projectDir])) {
            $this->projectsUsingImplicitNullableParamTypes[$projectDir] = true;
        }

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

$traverser = new PhpParser\NodeTraverser;
$traverser->addVisitor($visitor);

$it = new RecursiveIteratorIterator(
    new RecursiveDirectoryIterator(__DIR__ . '/sources'),
    RecursiveIteratorIterator::LEAVES_ONLY
);

$i = 0;
foreach ($it as $f) {
    $path = $f->getPathName();
    if (!preg_match('/\.php$/', $path)) {
        continue;
    }

    if (++$i % 1000 == 0) {
        echo $i . "\n";
    }

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

    $visitor->path = $path;
    $visitor->code = $code;
    $traverser->traverse($stmts);
}

echo "Total implicit nullable parameter types: ", $visitor->totalImplicitNullableParamTypes, "\n";
echo "Total projects using implicit nullable parameter types: ", count($visitor->projectsUsingImplicitNullableParamTypes), "\n";

foreach ($visitor->projectsUsingImplicitNullableParamTypes as $project => $_) {
    echo "$project\n";
}