DowngradeArraySpreadRector.php

<?php

declare(strict_types=1);

namespace Rector\DowngradePhp74\Rector\Array_;

use PhpParser\Node;
use PhpParser\Node\ArrayItem;
use PhpParser\Node\Expr\Array_;
use PhpParser\Node\Expr\ClassConstFetch;
use PhpParser\Node\Identifier;
use PhpParser\Node\Name;
use PhpParser\Node\Stmt\ClassConst;
use PhpParser\Node\Stmt\ClassLike;
use PHPStan\Analyser\MutatingScope;
use PHPStan\Type\Type;
use Rector\DowngradePhp81\NodeAnalyzer\ArraySpreadAnalyzer;
use Rector\DowngradePhp81\NodeFactory\ArrayMergeFromArraySpreadFactory;
use Rector\PhpParser\AstResolver;
use Rector\PhpParser\Node\BetterNodeFinder;
use Rector\PHPStan\ScopeFetcher;
use Rector\Rector\AbstractRector;
use Rector\StaticTypeMapper\ValueObject\Type\FullyQualifiedObjectType;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @changelog https://wiki.php.net/rfc/spread_operator_for_array
 *
 * @see \Rector\Tests\DowngradePhp74\Rector\Array_\DowngradeArraySpreadRector\DowngradeArraySpreadRectorTest
 */
final class DowngradeArraySpreadRector extends AbstractRector
{
    public function __construct(
        private readonly ArrayMergeFromArraySpreadFactory $arrayMergeFromArraySpreadFactory,
        private readonly ArraySpreadAnalyzer $arraySpreadAnalyzer,
        private readonly AstResolver $astResolver,
        private readonly BetterNodeFinder $betterNodeFinder
    ) {
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition(
            'Replace array spread with array_merge function',
            [
                new CodeSample(
                    <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $parts = ['apple', 'pear'];
        $fruits = ['banana', 'orange', ...$parts, 'watermelon'];
    }

    public function runWithIterable()
    {
        $fruits = ['banana', 'orange', ...new ArrayIterator(['durian', 'kiwi']), 'watermelon'];
    }
}
CODE_SAMPLE
                    ,
                    <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $parts = ['apple', 'pear'];
        $fruits = array_merge(['banana', 'orange'], $parts, ['watermelon']);
    }

    public function runWithIterable()
    {
        $fruits = array_merge(
            ['banana', 'orange'],
            is_array(new ArrayIterator(['durian', 'kiwi'])) ?
                new ArrayIterator(['durian', 'kiwi']) :
                iterator_to_array(new ArrayIterator(['durian', 'kiwi'])),
            ['watermelon']
        );
    }
}
CODE_SAMPLE
                ),
            ]
        );
    }

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

    /**
     * @param Array_|ClassConst $node
     */
    public function refactor(Node $node): ?Node
    {
        if ($node instanceof ClassConst) {
            return $this->refactorUnderClassConst($node);
        }

        if (! $this->arraySpreadAnalyzer->isArrayWithUnpack($node)) {
            return null;
        }

        /** @var MutatingScope $scope */
        $scope = ScopeFetcher::fetch($node);

        return $this->arrayMergeFromArraySpreadFactory->createFromArray($node, $scope);
    }

    private function refactorUnderClassConst(ClassConst $classConst): ?ClassConst
    {
        $arrays = $this->betterNodeFinder->findInstanceOf($classConst->consts, Array_::class);
        if ($arrays === []) {
            return null;
        }

        $hasChanged = false;

        $this->traverseNodesWithCallable($classConst->consts, function (Node $subNode) use (&$hasChanged): ?Node {
            if (! $subNode instanceof Array_) {
                return null;
            }

            $refactorArrayConstValue = $this->refactorArrayConstValue($subNode);
            if ($refactorArrayConstValue instanceof Array_) {
                $hasChanged = true;
                return $refactorArrayConstValue;
            }

            return null;
        });

        if ($hasChanged) {
            return $classConst;
        }

        return null;
    }

    private function resolveItemType(?ArrayItem $arrayItem): ?Type
    {
        if (! $arrayItem instanceof ArrayItem) {
            return null;
        }

        if (! $arrayItem->unpack) {
            return null;
        }

        if (! $arrayItem->value instanceof ClassConstFetch) {
            return null;
        }

        if (! $arrayItem->value->class instanceof Name) {
            return null;
        }

        if (! $arrayItem->value->name instanceof Identifier) {
            return null;
        }

        return $this->nodeTypeResolver->getType($arrayItem->value->class);
    }

    private function refactorArrayConstValue(Array_ $array): ?Array_
    {
        $hasChanged = false;

        $newArray = new Array_();
        $newArray->setAttributes($array->getAttributes());

        foreach ($array->items as $item) {
            $newArray->items[] = $item;
            $type = $this->resolveItemType($item);
            if (! $type instanceof FullyQualifiedObjectType) {
                continue;
            }

            $value = $item->value;
            /** @var ClassConstFetch $value */
            $name = $value->name;

            /** @var Identifier $name */
            $classLike = $this->astResolver->resolveClassFromName($type->getClassName());
            if (! $classLike instanceof ClassLike) {
                continue;
            }

            $constants = $classLike->getConstants();

            foreach ($constants as $constant) {
                $const = $constant->consts[0];

                if ($const->name->toString() === $name->toString() && $const->value instanceof Array_) {
                    array_pop($newArray->items);
                    $newArray->items = array_merge($newArray->items, $const->value->items);

                    $hasChanged = true;
                }
            }
        }

        if ($hasChanged) {
            return $newArray;
        }

        return null;
    }
}