rector/rules/CodeQuality/Rector/If_/SimplifyIfReturnBoolRector.php

<?php

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

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\BinaryOp\Identical;
use PhpParser\Node\Expr\BinaryOp\NotIdentical;
use PhpParser\Node\Expr\BooleanNot;
use PhpParser\Node\Stmt\If_;
use PhpParser\Node\Stmt\Return_;
use Rector\BetterPhpDocParser\Comment\CommentsMerger;
use Rector\CodeQuality\NodeManipulator\ExprBoolCaster;
use Rector\Core\Contract\PhpParser\NodePrinterInterface;
use Rector\Core\Rector\AbstractRector;
use Rector\NodeTypeResolver\Node\AttributeKey;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
/**
 * @see \Rector\Tests\CodeQuality\Rector\If_\SimplifyIfReturnBoolRector\SimplifyIfReturnBoolRectorTest
 */
final class SimplifyIfReturnBoolRector extends AbstractRector
{
    /**
     * @readonly
     * @var \Rector\BetterPhpDocParser\Comment\CommentsMerger
     */
    private $commentsMerger;
    /**
     * @readonly
     * @var \Rector\CodeQuality\NodeManipulator\ExprBoolCaster
     */
    private $exprBoolCaster;
    /**
     * @readonly
     * @var \Rector\Core\Contract\PhpParser\NodePrinterInterface
     */
    private $nodePrinter;
    public function __construct(CommentsMerger $commentsMerger, ExprBoolCaster $exprBoolCaster, NodePrinterInterface $nodePrinter)
    {
        $this->commentsMerger = $commentsMerger;
        $this->exprBoolCaster = $exprBoolCaster;
        $this->nodePrinter = $nodePrinter;
    }
    public function getRuleDefinition() : RuleDefinition
    {
        return new RuleDefinition('Shortens if return false/true to direct return', [new CodeSample(<<<'CODE_SAMPLE'
if (strpos($docToken->getContent(), "\n") === false) {
    return true;
}

return false;
CODE_SAMPLE
, 'return strpos($docToken->getContent(), "\\n") === false;')]);
    }
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [If_::class];
    }
    /**
     * @param If_ $node
     */
    public function refactor(Node $node) : ?Node
    {
        if ($this->shouldSkip($node)) {
            return null;
        }
        /** @var Return_ $ifInnerNode */
        $ifInnerNode = $node->stmts[0];
        /** @var Return_ $nextNode */
        $nextNode = $node->getAttribute(AttributeKey::NEXT_NODE);
        $innerIfInnerNode = $ifInnerNode->expr;
        if (!$innerIfInnerNode instanceof Expr) {
            return null;
        }
        if ($this->valueResolver->isTrue($innerIfInnerNode)) {
            $newReturnNode = $this->processReturnTrue($node, $nextNode);
        } elseif ($this->valueResolver->isFalse($innerIfInnerNode)) {
            /** @var Expr $expr */
            $expr = $nextNode->expr;
            if ($node->cond instanceof NotIdentical && $this->valueResolver->isTrue($expr)) {
                $node->cond = new Identical($node->cond->left, $node->cond->right);
                $newReturnNode = $this->processReturnTrue($node, $nextNode);
            } else {
                $newReturnNode = $this->processReturnFalse($node, $nextNode);
            }
        } else {
            return null;
        }
        if (!$newReturnNode instanceof Return_) {
            return null;
        }
        $this->commentsMerger->keepComments($newReturnNode, [$node, $ifInnerNode, $nextNode, $newReturnNode]);
        $this->removeNode($nextNode);
        return $newReturnNode;
    }
    private function shouldSkip(If_ $if) : bool
    {
        if ($if->elseifs !== []) {
            return \true;
        }
        if ($this->isElseSeparatedThenIf($if)) {
            return \true;
        }
        if (!$this->isIfWithSingleReturnExpr($if)) {
            return \true;
        }
        /** @var Return_ $ifInnerNode */
        $ifInnerNode = $if->stmts[0];
        /** @var Expr $returnedExpr */
        $returnedExpr = $ifInnerNode->expr;
        if (!$this->valueResolver->isTrueOrFalse($returnedExpr)) {
            return \true;
        }
        $nextNode = $if->getAttribute(AttributeKey::NEXT_NODE);
        if (!$nextNode instanceof Return_) {
            return \true;
        }
        if (!$nextNode->expr instanceof Expr) {
            return \true;
        }
        // negate + negate → skip for now
        if (!$this->valueResolver->isFalse($returnedExpr)) {
            return !$this->valueResolver->isTrueOrFalse($nextNode->expr);
        }
        $condString = $this->nodePrinter->print($if->cond);
        if (\strpos($condString, '!=') === \false) {
            return !$this->valueResolver->isTrueOrFalse($nextNode->expr);
        }
        return !$if->cond instanceof NotIdentical;
    }
    private function processReturnTrue(If_ $if, Return_ $nextReturnNode) : Return_
    {
        if ($if->cond instanceof BooleanNot && $nextReturnNode->expr !== null && $this->valueResolver->isTrue($nextReturnNode->expr)) {
            return new Return_($this->exprBoolCaster->boolCastOrNullCompareIfNeeded($if->cond->expr));
        }
        return new Return_($this->exprBoolCaster->boolCastOrNullCompareIfNeeded($if->cond));
    }
    private function processReturnFalse(If_ $if, Return_ $nextReturnNode) : ?Return_
    {
        if ($if->cond instanceof Identical) {
            $notIdentical = new NotIdentical($if->cond->left, $if->cond->right);
            return new Return_($this->exprBoolCaster->boolCastOrNullCompareIfNeeded($notIdentical));
        }
        if ($nextReturnNode->expr === null) {
            return null;
        }
        if (!$this->valueResolver->isTrue($nextReturnNode->expr)) {
            return null;
        }
        if ($if->cond instanceof BooleanNot) {
            return new Return_($this->exprBoolCaster->boolCastOrNullCompareIfNeeded($if->cond->expr));
        }
        return new Return_($this->exprBoolCaster->boolCastOrNullCompareIfNeeded(new BooleanNot($if->cond)));
    }
    /**
     * Matches: "else if"
     */
    private function isElseSeparatedThenIf(If_ $if) : bool
    {
        if ($if->else === null) {
            return \false;
        }
        if (\count($if->else->stmts) !== 1) {
            return \false;
        }
        $onlyStmt = $if->else->stmts[0];
        return $onlyStmt instanceof If_;
    }
    private function isIfWithSingleReturnExpr(If_ $if) : bool
    {
        if (\count($if->stmts) !== 1) {
            return \false;
        }
        if ($if->elseifs !== []) {
            return \false;
        }
        $ifInnerNode = $if->stmts[0];
        if (!$ifInnerNode instanceof Return_) {
            return \false;
        }
        // return must have value
        return $ifInnerNode->expr !== null;
    }
}