OptionalParametersAfterRequiredRector.php

<?php

declare(strict_types=1);

namespace Rector\CodeQuality\Rector\ClassMethod;

use PhpParser\Node;
use PhpParser\Node\ComplexType;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Closure;
use PhpParser\Node\Expr\ConstFetch;
use PhpParser\Node\Identifier;
use PhpParser\Node\IntersectionType;
use PhpParser\Node\Name;
use PhpParser\Node\NullableType;
use PhpParser\Node\Param;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Function_;
use PhpParser\Node\UnionType;
use Rector\Rector\AbstractRector;
use Rector\ValueObject\PhpVersionFeature;
use Rector\VersionBonding\Contract\MinPhpVersionInterface;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\Tests\CodeQuality\Rector\ClassMethod\OptionalParametersAfterRequiredRector\OptionalParametersAfterRequiredRectorTest
 */
final class OptionalParametersAfterRequiredRector extends AbstractRector implements MinPhpVersionInterface
{
    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Add null default value when a required parameter follows an optional one', [
            new CodeSample(
                <<<'CODE_SAMPLE'
class SomeObject
{
    public function run($optional = 1, $required)
    {
    }
}
CODE_SAMPLE

                ,
                <<<'CODE_SAMPLE'
class SomeObject
{
    public function run($optional = 1, $required = null)
    {
    }
}
CODE_SAMPLE
            ),
        ]);
    }

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

    /**
     * @param ClassMethod|Function_|Closure $node
     */
    public function refactor(Node $node): ClassMethod|Function_|Closure|null
    {
        if ($node->params === []) {
            return null;
        }

        $hasChanged = false;
        foreach ($node->params as $key => $param) {
            if ($param->default instanceof Expr) {
                continue;
            }

            if ($param->variadic) {
                continue;
            }

            $previousParam = $node->params[$key - 1] ?? null;
            if ($previousParam instanceof Param && $previousParam->default instanceof Expr) {
                $hasChanged = true;

                $param->default = new ConstFetch(new Name('null'));

                if (! $param->type instanceof Node) {
                    continue;
                }

                if ($param->type instanceof NullableType) {
                    continue;
                }

                if ($param->type instanceof UnionType) {
                    foreach ($param->type->types as $unionedType) {
                        if ($unionedType instanceof Identifier && $this->isName($unionedType, 'null')) {
                            continue 2;
                        }
                    }

                    $param->type->types[] = new Identifier('null');
                    continue;
                }

                if ($param->type instanceof IntersectionType) {
                    $param->type = new UnionType([$param->type, new Identifier('null')]);

                    continue;
                }

                if ($param->type instanceof ComplexType) {
                    continue;
                }

                $param->type = new NullableType($param->type);
            }
        }

        return $hasChanged ? $node : null;
    }

    public function provideMinPhpVersion(): int
    {
        return PhpVersionFeature::NULLABLE_TYPE;
    }
}