RemoveDeadZeroAndOneOperationRector.php

<?php

declare (strict_types=1);
namespace Rector\DeadCode\Rector\Plus;

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\AssignOp;
use PhpParser\Node\Expr\AssignOp\Div as AssignDiv;
use PhpParser\Node\Expr\AssignOp\Minus as AssignMinus;
use PhpParser\Node\Expr\AssignOp\Mul as AssignMul;
use PhpParser\Node\Expr\AssignOp\Plus as AssignPlus;
use PhpParser\Node\Expr\BinaryOp;
use PhpParser\Node\Expr\BinaryOp\Div;
use PhpParser\Node\Expr\BinaryOp\Minus;
use PhpParser\Node\Expr\BinaryOp\Mul;
use PhpParser\Node\Expr\BinaryOp\Plus;
use PhpParser\Node\Expr\ClassConstFetch;
use PhpParser\Node\Expr\UnaryMinus;
use Rector\PhpParser\Node\Value\ValueResolver;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
/**
 * @see \Rector\Tests\DeadCode\Rector\Plus\RemoveDeadZeroAndOneOperationRector\RemoveDeadZeroAndOneOperationRectorTest
 */
final class RemoveDeadZeroAndOneOperationRector extends AbstractRector
{
    /**
     * @readonly
     * @var \Rector\PhpParser\Node\Value\ValueResolver
     */
    private $valueResolver;
    public function __construct(ValueResolver $valueResolver)
    {
        $this->valueResolver = $valueResolver;
    }
    public function getRuleDefinition() : RuleDefinition
    {
        return new RuleDefinition('Remove operation with 1 and 0, that have no effect on the value', [new CodeSample(<<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $value = 5 * 1;
        $value = 5 + 0;
    }
}
CODE_SAMPLE
, <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $value = 5;
        $value = 5;
    }
}
CODE_SAMPLE
)]);
    }
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [Plus::class, Minus::class, Mul::class, Div::class, AssignPlus::class, AssignMinus::class, AssignMul::class, AssignDiv::class];
    }
    /**
     * @param Plus|Minus|Mul|Div|AssignPlus|AssignMinus|AssignMul|AssignDiv $node
     */
    public function refactor(Node $node) : ?Node
    {
        if ($node instanceof AssignOp) {
            return $this->processAssignOp($node);
        }
        // -, +
        return $this->processBinaryOp($node);
    }
    private function processAssignOp(AssignOp $assignOp) : ?Expr
    {
        // +=, -=
        if ($assignOp instanceof AssignPlus || $assignOp instanceof AssignMinus) {
            if (!$this->valueResolver->isValue($assignOp->expr, 0)) {
                return null;
            }
            if ($this->nodeTypeResolver->isNumberType($assignOp->var)) {
                return $assignOp->var;
            }
        }
        // *, /
        if ($assignOp instanceof AssignMul || $assignOp instanceof AssignDiv) {
            if (!$this->valueResolver->isValue($assignOp->expr, 1)) {
                return null;
            }
            if ($this->nodeTypeResolver->isNumberType($assignOp->var)) {
                return $assignOp->var;
            }
        }
        return null;
    }
    private function processBinaryOp(Node $node) : ?Expr
    {
        if ($node instanceof Plus || $node instanceof Minus) {
            return $this->processBinaryPlusAndMinus($node);
        }
        // *, /
        if ($node instanceof Mul) {
            return $this->processBinaryMulAndDiv($node);
        }
        if ($node instanceof Div) {
            return $this->processBinaryMulAndDiv($node);
        }
        return null;
    }
    private function areNumberType(BinaryOp $binaryOp) : bool
    {
        if (!$this->nodeTypeResolver->isNumberType($binaryOp->left)) {
            return \false;
        }
        return $this->nodeTypeResolver->isNumberType($binaryOp->right);
    }
    /**
     * @param \PhpParser\Node\Expr\BinaryOp\Plus|\PhpParser\Node\Expr\BinaryOp\Minus $binaryOp
     */
    private function processBinaryPlusAndMinus($binaryOp) : ?Expr
    {
        if (!$this->areNumberType($binaryOp)) {
            return null;
        }
        if ($this->valueResolver->isValue($binaryOp->left, 0) && $this->nodeTypeResolver->isNumberType($binaryOp->right)) {
            if ($binaryOp instanceof Minus) {
                return new UnaryMinus($binaryOp->right);
            }
            return $binaryOp->right;
        }
        if (!$this->valueResolver->isValue($binaryOp->right, 0)) {
            return null;
        }
        return $binaryOp->left;
    }
    /**
     * @param \PhpParser\Node\Expr\BinaryOp\Mul|\PhpParser\Node\Expr\BinaryOp\Div $binaryOp
     */
    private function processBinaryMulAndDiv($binaryOp) : ?Expr
    {
        if ($binaryOp->left instanceof ClassConstFetch || $binaryOp->right instanceof ClassConstFetch) {
            return null;
        }
        if (!$this->areNumberType($binaryOp)) {
            return null;
        }
        if ($binaryOp instanceof Mul && $this->valueResolver->isValue($binaryOp->left, 1) && $this->nodeTypeResolver->isNumberType($binaryOp->right)) {
            return $binaryOp->right;
        }
        if (!$this->valueResolver->isValue($binaryOp->right, 1)) {
            return null;
        }
        return $binaryOp->left;
    }
}