PrivatizeFinalClassConstantRector.php

<?php

declare(strict_types=1);

namespace Rector\Privatization\Rector\ClassConst;

use PhpParser\Node;
use PhpParser\Node\Stmt\Class_;
use PhpParser\Node\Stmt\ClassConst;
use PHPStan\Reflection\ClassReflection;
use Rector\PHPStan\ScopeFetcher;
use Rector\Privatization\Guard\OverrideByParentClassGuard;
use Rector\Privatization\NodeManipulator\VisibilityManipulator;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\Tests\Privatization\Rector\ClassConst\PrivatizeFinalClassConstantRector\PrivatizeFinalClassConstantRectorTest
 */
final class PrivatizeFinalClassConstantRector extends AbstractRector
{
    public function __construct(
        private readonly VisibilityManipulator $visibilityManipulator,
        private readonly OverrideByParentClassGuard $overrideByParentClassGuard,
    ) {
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Change protected constant to private if possible', [
            new CodeSample(
                <<<'CODE_SAMPLE'
final class SomeClass
{
    protected const SOME_CONSTANT = 'some-value';
}
CODE_SAMPLE
                ,
                <<<'CODE_SAMPLE'
final class SomeClass
{
    private const SOME_CONSTANT = 'some-value';
}
CODE_SAMPLE
            ),
        ]);
    }

    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes(): array
    {
        return [Class_::class];
    }

    /**
     * @param Class_ $node
     */
    public function refactor(Node $node): ?Node
    {
        if (! $node->isFinal()) {
            return null;
        }

        if (! $this->overrideByParentClassGuard->isLegal($node)) {
            return null;
        }

        $scope = ScopeFetcher::fetch($node);
        $classReflection = $scope->getClassReflection();
        if (! $classReflection instanceof ClassReflection) {
            return null;
        }

        $hasChanged = false;

        foreach ($node->getConstants() as $classConst) {
            if ($this->shouldSkipClassConst($classConst)) {
                continue;
            }

            if ($this->isDefinedInParentOrInterface($classConst, $classReflection)) {
                continue;
            }

            $this->visibilityManipulator->makePrivate($classConst);
            $hasChanged = true;
        }

        if ($hasChanged) {
            return $node;
        }

        return null;
    }

    private function shouldSkipClassConst(ClassConst $classConst): bool
    {
        // Skip if multiple constants are defined in one line to avoid partial visibility complexity
        if (count($classConst->consts) !== 1) {
            return true;
        }

        return ! $classConst->isProtected();
    }

    private function isDefinedInParentOrInterface(ClassConst $classConst, ClassReflection $classReflection): bool
    {
        $constantName = $this->getName($classConst);
        if ($constantName === null) {
            return true;
        }

        foreach ($classReflection->getAncestors() as $ancestorClassReflection) {
            // Skip the class itself
            if ($ancestorClassReflection->getName() === $classReflection->getName()) {
                continue;
            }

            if ($ancestorClassReflection->hasConstant($constantName)) {
                return true;
            }
        }

        return false;
    }
}