rector/packages/CodeQuality/src/Rector/If_/ShortenElseIfRector.php

<?php

declare(strict_types=1);

namespace Rector\CodeQuality\Rector\If_;

use PhpParser\Node;
use PhpParser\Node\Stmt\ElseIf_;
use PhpParser\Node\Stmt\If_;
use Rector\Rector\AbstractRector;
use Rector\RectorDefinition\CodeSample;
use Rector\RectorDefinition\RectorDefinition;

/**
 * @see \Rector\CodeQuality\Tests\Rector\If_\ShortenElseIfRector\ShortenElseIfRectorTest
 */
final class ShortenElseIfRector extends AbstractRector
{
    public function getDefinition(): RectorDefinition
    {
        return new RectorDefinition('Shortens else/if to elseif', [
            new CodeSample(
                <<<'PHP'
class SomeClass
{
    public function run()
    {
        if ($cond1) {
            return $action1;
        } else {
            if ($cond2) {
                return $action2;
            }
        }
    }
}
PHP
                ,
                <<<'PHP'
class SomeClass
{
    public function run()
    {
        if ($cond1) {
            return $action1;
        } elseif ($cond2) {
            return $action2;
        }    
    }
}
PHP
            ),
        ]);
    }

    /**
     * @return string[]
     */
    public function getNodeTypes(): array
    {
        return [If_::class];
    }

    /**
     * @param If_ $node
     */
    public function refactor(Node $node): ?Node
    {
        return $this->shortenElseIf($node);
    }

    private function shortenElseIf(If_ $node): ?Node
    {
        if ($node->else === null) {
            return null;
        }

        $else = $node->else;
        if (count($else->stmts) > 1) {
            return null;
        }

        $if = $else->stmts[0];
        if (! $if instanceof If_) {
            return null;
        }

        // Try to shorten the nested if before transforming it to elseif
        $refactored = $this->shortenElseIf($if);

        if ($refactored !== null) {
            $if = $refactored;
        }

        $node->elseifs[] = new ElseIf_($if->cond, $if->stmts);

        $node->else = $if->else;

        $node->elseifs = array_merge($node->elseifs, $if->elseifs);

        return $node;
    }
}