UnnecessaryTernaryExpressionRector.php

<?php

declare (strict_types=1);
namespace Rector\CodeQuality\Rector\Ternary;

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\BinaryOp;
use PhpParser\Node\Expr\BooleanNot;
use PhpParser\Node\Expr\Cast\Bool_;
use PhpParser\Node\Expr\Ternary;
use Rector\PhpParser\Node\AssignAndBinaryMap;
use Rector\PhpParser\Node\Value\ValueResolver;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
/**
 * @see \Rector\Tests\CodeQuality\Rector\Ternary\UnnecessaryTernaryExpressionRector\UnnecessaryTernaryExpressionRectorTest
 */
final class UnnecessaryTernaryExpressionRector extends AbstractRector
{
    /**
     * @readonly
     */
    private AssignAndBinaryMap $assignAndBinaryMap;
    /**
     * @readonly
     */
    private ValueResolver $valueResolver;
    public function __construct(AssignAndBinaryMap $assignAndBinaryMap, ValueResolver $valueResolver)
    {
        $this->assignAndBinaryMap = $assignAndBinaryMap;
        $this->valueResolver = $valueResolver;
    }
    public function getRuleDefinition() : RuleDefinition
    {
        return new RuleDefinition('Remove unnecessary ternary expressions', [new CodeSample('$foo === $bar ? true : false;', '$foo === $bar;')]);
    }
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [Ternary::class];
    }
    /**
     * @param Ternary $node
     */
    public function refactor(Node $node) : ?Node
    {
        if (!$node->if instanceof Expr) {
            return null;
        }
        $ifExpression = $node->if;
        if (!$this->valueResolver->isTrueOrFalse($ifExpression)) {
            return null;
        }
        $elseExpression = $node->else;
        if (!$this->valueResolver->isTrueOrFalse($elseExpression)) {
            return null;
        }
        $condition = $node->cond;
        if (!$condition instanceof BinaryOp) {
            return $this->processNonBinaryCondition($ifExpression, $elseExpression, $condition);
        }
        if ($this->valueResolver->isNull($ifExpression)) {
            return null;
        }
        if ($this->valueResolver->isNull($elseExpression)) {
            return null;
        }
        /** @var BinaryOp $binaryOperation */
        $binaryOperation = $node->cond;
        if ($this->valueResolver->isTrue($ifExpression) && $this->valueResolver->isFalse($elseExpression)) {
            return $binaryOperation;
        }
        $inversedBinaryClass = $this->assignAndBinaryMap->getInversed($binaryOperation);
        if ($inversedBinaryClass === null) {
            return null;
        }
        return new $inversedBinaryClass($binaryOperation->left, $binaryOperation->right);
    }
    private function processNonBinaryCondition(Expr $ifExpression, Expr $elseExpression, Expr $condition) : ?Node
    {
        if ($this->valueResolver->isTrue($ifExpression) && $this->valueResolver->isFalse($elseExpression)) {
            return $this->processTrueIfExpressionWithFalseElseExpression($condition);
        }
        if (!$this->valueResolver->isFalse($ifExpression)) {
            return null;
        }
        if (!$this->valueResolver->isTrue($elseExpression)) {
            return null;
        }
        return $this->processFalseIfExpressionWithTrueElseExpression($condition);
    }
    private function processTrueIfExpressionWithFalseElseExpression(Expr $expr) : Expr
    {
        $exprType = $this->getType($expr);
        if ($exprType->isBoolean()->yes()) {
            return $expr;
        }
        return new Bool_($expr);
    }
    private function processFalseIfExpressionWithTrueElseExpression(Expr $expr) : Expr
    {
        if ($expr instanceof BooleanNot) {
            $negatedExprType = $this->getType($expr->expr);
            if ($negatedExprType->isBoolean()->yes()) {
                return $expr->expr;
            }
            return new Bool_($expr->expr);
        }
        $exprType = $this->getType($expr);
        if ($exprType->isBoolean()->yes()) {
            return new BooleanNot($expr);
        }
        return new BooleanNot(new Bool_($expr));
    }
}