BinaryOpBetweenNumberAndStringRector.php

<?php

declare(strict_types=1);

namespace Rector\Php71\Rector\BinaryOp;

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\BinaryOp;
use PhpParser\Node\Expr\BinaryOp\Coalesce;
use PhpParser\Node\Expr\BinaryOp\Concat;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Scalar;
use PhpParser\Node\Scalar\LNumber;
use PhpParser\Node\Scalar\String_;
use PHPStan\Type\Constant\ConstantStringType;
use Rector\Core\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see https://3v4l.org/XPEEl
 * @see https://3v4l.org/ObNQZ
 * @see \Rector\Tests\Php71\Rector\BinaryOp\BinaryOpBetweenNumberAndStringRector\BinaryOpBetweenNumberAndStringRectorTest
 */
final class BinaryOpBetweenNumberAndStringRector extends AbstractRector
{
    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition(
            'Change binary operation between some number + string to PHP 7.1 compatible version',
            [
                new CodeSample(
                    <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $value = 5 + '';
        $value = 5.0 + 'hi';
    }
}
CODE_SAMPLE
                    ,
                    <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $value = 5 + 0;
        $value = 5.0 + 0
    }
}
CODE_SAMPLE
                ),
            ]
        );
    }

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

    /**
     * @param BinaryOp $node
     */
    public function refactor(Node $node): ?Node
    {
        if ($node instanceof Concat) {
            return null;
        }
        if ($node instanceof Coalesce) {
            return null;
        }
        if ($this->isStringOrStaticNonNumbericString($node->left) && $this->nodeTypeResolver->isNumberType(
            $node->right
        )) {
            $node->left = new LNumber(0);

            return $node;
        }

        if ($this->isStringOrStaticNonNumbericString($node->right) && $this->nodeTypeResolver->isNumberType(
            $node->left
        )) {
            $node->right = new LNumber(0);

            return $node;
        }

        return null;
    }

    private function isStringOrStaticNonNumbericString(Expr $expr): bool
    {
        // replace only scalar values, not variables/constants/etc.
        if (! $expr instanceof Scalar && ! $expr instanceof Variable) {
            return false;
        }

        $value = null;
        $exprStaticType = $this->getStaticType($expr);

        if ($expr instanceof String_) {
            $value = $expr->value;
        } elseif ($exprStaticType instanceof ConstantStringType) {
            $value = $exprStaticType->getValue();
        } else {
            return false;
        }

        return ! is_numeric($value);
    }
}