DowngradeNullsafeToTernaryOperatorRector.php

<?php

declare(strict_types=1);

namespace Rector\DowngradePhp80\Rector\NullsafeMethodCall;

use PhpParser\Node;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\NullsafeMethodCall;
use PhpParser\Node\Expr\NullsafePropertyFetch;
use PhpParser\Node\Expr\PropertyFetch;
use PhpParser\Node\Expr\Ternary;
use PhpParser\Node\Expr\Variable;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\Tests\DowngradePhp80\Rector\NullsafeMethodCall\DowngradeNullsafeToTernaryOperatorRector\DowngradeNullsafeToTernaryOperatorRectorTest
 */
final class DowngradeNullsafeToTernaryOperatorRector extends AbstractRector
{
    private int $counter = 0;

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Change nullsafe operator to ternary operator rector', [
            new CodeSample(
                <<<'CODE_SAMPLE'
$dateAsString = $booking->getStartDate()?->asDateTimeString();
CODE_SAMPLE
                ,
                <<<'CODE_SAMPLE'
$dateAsString = ($bookingGetStartDate = $booking->getStartDate()) ? $bookingGetStartDate->asDateTimeString() : null;
CODE_SAMPLE
            ),
        ]);
    }

    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes(): array
    {
        return [MethodCall::class, PropertyFetch::class, NullsafeMethodCall::class, NullsafePropertyFetch::class];
    }

    /**
     * @param MethodCall|NullsafeMethodCall|NullsafePropertyFetch $node
     */
    public function refactor(Node $node): ?Ternary
    {
        static $currentFile = null;

        if ($currentFile !== $this->file->getFilePath()) {
            $this->counter = 0;
            $currentFile = $this->file->getFilePath();
        }

        if ($node instanceof MethodCall || $node instanceof PropertyFetch) {
            if ($node->var instanceof NullsafeMethodCall || $node->var instanceof NullsafePropertyFetch) {
                $nullsafeVariable = $this->createNullsafeVariable();

                $assign = new Assign($nullsafeVariable, $node->var->var);
                if ($node instanceof MethodCall) {
                    if ($node->var instanceof NullsafeMethodCall) {
                        $methodCallOrPropertyFetch = new MethodCall(new MethodCall(
                            $nullsafeVariable,
                            $node->var->name,
                            $node->var->args
                        ), $node->name, $node->args);
                        return new Ternary($assign, $methodCallOrPropertyFetch, $this->nodeFactory->createNull());
                    }

                    $methodCallOrPropertyFetch = new MethodCall(new PropertyFetch(
                        $nullsafeVariable,
                        $node->var->name
                    ), $node->name, $node->args);
                    return new Ternary($assign, $methodCallOrPropertyFetch, $this->nodeFactory->createNull());
                }

                if ($node->var instanceof NullsafeMethodCall) {
                    $methodCallOrPropertyFetch = new PropertyFetch(new MethodCall(
                        $nullsafeVariable,
                        $node->var->name,
                        $node->var->args
                    ), $node->name);
                    return new Ternary($assign, $methodCallOrPropertyFetch, $this->nodeFactory->createNull());
                }

                $methodCallOrPropertyFetch = new PropertyFetch(new PropertyFetch(
                    $nullsafeVariable,
                    $node->var->name
                ), $node->name);
                return new Ternary($assign, $methodCallOrPropertyFetch, $this->nodeFactory->createNull());
            }

            return null;
        }

        $nullsafeVariable = $this->createNullsafeVariable();

        $methodCallOrPropertyFetch = $node instanceof NullsafeMethodCall
            ? new MethodCall($nullsafeVariable, $node->name, $node->args)
            : new PropertyFetch($nullsafeVariable, $node->name);

        $assign = new Assign($nullsafeVariable, $node->var);

        return new Ternary($assign, $methodCallOrPropertyFetch, $this->nodeFactory->createNull());
    }

    private function createNullsafeVariable(): Variable
    {
        $nullsafeVariableName = 'nullsafeVariable' . ++$this->counter;
        return new Variable($nullsafeVariableName);
    }
}