rector/rules/EarlyReturn/Rector/Foreach_/ChangeNestedForeachIfsToEarlyContinueRector.php

<?php

declare(strict_types=1);

namespace Rector\EarlyReturn\Rector\Foreach_;

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\BinaryOp\BooleanAnd;
use PhpParser\Node\Expr\BinaryOp\BooleanOr;
use PhpParser\Node\Expr\BinaryOp\Equal;
use PhpParser\Node\Expr\BinaryOp\NotEqual;
use PhpParser\Node\Expr\BooleanNot;
use PhpParser\Node\Stmt\Continue_;
use PhpParser\Node\Stmt\Foreach_;
use PhpParser\Node\Stmt\If_;
use Rector\Core\NodeManipulator\IfManipulator;
use Rector\Core\Rector\AbstractRector;
use Rector\EarlyReturn\NodeTransformer\ConditionInverter;
use Rector\NodeTypeResolver\Node\AttributeKey;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\Tests\EarlyReturn\Rector\Foreach_\ChangeNestedForeachIfsToEarlyContinueRector\ChangeNestedForeachIfsToEarlyContinueRectorTest
 */
final class ChangeNestedForeachIfsToEarlyContinueRector extends AbstractRector
{
    /**
     * @var IfManipulator
     */
    private $ifManipulator;

    /**
     * @var ConditionInverter
     */
    private $conditionInverter;

    public function __construct(ConditionInverter $conditionInverter, IfManipulator $ifManipulator)
    {
        $this->ifManipulator = $ifManipulator;
        $this->conditionInverter = $conditionInverter;
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Change nested ifs to foreach with continue', [
            new CodeSample(
                <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $items = [];

        foreach ($values as $value) {
            if ($value === 5) {
                if ($value2 === 10) {
                    $items[] = 'maybe';
                }
            }
        }
    }
}
CODE_SAMPLE
,
                <<<'CODE_SAMPLE'
class SomeClass
{
    public function run()
    {
        $items = [];

        foreach ($values as $value) {
            if ($value !== 5) {
                continue;
            }
            if ($value2 !== 10) {
                continue;
            }

            $items[] = 'maybe';
        }
    }
}
CODE_SAMPLE
            ),
        ]);
    }

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

    /**
     * @param Foreach_ $node
     */
    public function refactor(Node $node): ?Node
    {
        $nestedIfsWithOnlyNonReturn = $this->ifManipulator->collectNestedIfsWithNonBreaking($node);
        if (count($nestedIfsWithOnlyNonReturn) < 2) {
            return null;
        }

        return $this->processNestedIfsWithNonBreaking($node, $nestedIfsWithOnlyNonReturn);
    }

    /**
     * @param If_[] $nestedIfsWithOnlyReturn
     */
    private function processNestedIfsWithNonBreaking(Foreach_ $foreach, array $nestedIfsWithOnlyReturn): Foreach_
    {
        // add nested if openly after this
        $nestedIfsWithOnlyReturnCount = count($nestedIfsWithOnlyReturn);

        // clear
        $foreach->stmts = [];

        foreach ($nestedIfsWithOnlyReturn as $key => $nestedIfWithOnlyReturn) {
            // last item → the return node
            if ($nestedIfsWithOnlyReturnCount === $key + 1) {
                $finalReturn = clone $nestedIfWithOnlyReturn;

                $this->addInvertedIfStmtWithContinue($nestedIfWithOnlyReturn, $foreach);

                // should skip for weak inversion
                if ($this->isBooleanOrWithWeakComparison($nestedIfWithOnlyReturn->cond)) {
                    continue;
                }

                $foreach->stmts = array_merge($foreach->stmts, $finalReturn->stmts);
            } else {
                $this->addInvertedIfStmtWithContinue($nestedIfWithOnlyReturn, $foreach);
            }
        }

        return $foreach;
    }

    private function addInvertedIfStmtWithContinue(If_ $nestedIfWithOnlyReturn, Foreach_ $foreach): void
    {
        $invertedCondition = $this->conditionInverter->createInvertedCondition($nestedIfWithOnlyReturn->cond);

        // special case
        if ($invertedCondition instanceof BooleanNot && $invertedCondition->expr instanceof BooleanAnd) {
            $leftExpr = $this->negateOrDeNegate($invertedCondition->expr->left);
            $if = new If_($leftExpr);
            $if->stmts[] = new Continue_();
            $foreach->stmts[] = $if;

            $rightExpr = $this->negateOrDeNegate($invertedCondition->expr->right);
            $if = new If_($rightExpr);
            $if->stmts[] = new Continue_();
            $foreach->stmts[] = $if;

            return;
        }

        // should skip for weak inversion
        if ($this->isBooleanOrWithWeakComparison($nestedIfWithOnlyReturn->cond)) {
            $foreach->stmts[] = $nestedIfWithOnlyReturn;

            return;
        }

        $nestedIfWithOnlyReturn->setAttribute(AttributeKey::ORIGINAL_NODE, null);

        $nestedIfWithOnlyReturn->cond = $invertedCondition;
        $nestedIfWithOnlyReturn->stmts = [new Continue_()];

        $foreach->stmts[] = $nestedIfWithOnlyReturn;
    }

    /**
     * Matches:
     * $a == 1 || $b == 1
     *
     * Skips:
     * $a === 1 || $b === 2
     */
    private function isBooleanOrWithWeakComparison(Expr $expr): bool
    {
        if (! $expr instanceof BooleanOr) {
            return false;
        }

        if ($expr->left instanceof Equal) {
            return true;
        }

        if ($expr->left instanceof NotEqual) {
            return true;
        }

        if ($expr->right instanceof Equal) {
            return true;
        }

        return $expr->right instanceof NotEqual;
    }

    private function negateOrDeNegate(Expr $expr): Expr
    {
        if ($expr instanceof BooleanNot) {
            return $expr->expr;
        }

        return new BooleanNot($expr);
    }
}