NullableObjectAssignCollector.php

<?php

declare(strict_types=1);

namespace Rector\PHPUnit\CodeQuality\NodeAnalyser;

use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Expression;
use PhpParser\Node\Stmt\Foreach_;
use PHPStan\Type\ObjectType;
use PHPStan\Type\TypeCombinator;
use Rector\NodeNameResolver\NodeNameResolver;
use Rector\NodeTypeResolver\NodeTypeResolver;
use Rector\PHPUnit\CodeQuality\ValueObject\VariableNameToType;
use Rector\PHPUnit\CodeQuality\ValueObject\VariableNameToTypeCollection;

/**
 * We look for object|null type on the left:
 *
 * $value = $this->getSomething();
 */
final readonly class NullableObjectAssignCollector
{
    public function __construct(
        private NodeNameResolver $nodeNameResolver,
        private NodeTypeResolver $nodeTypeResolver,
    ) {
    }

    public function collect(ClassMethod|Foreach_ $stmtsAware): VariableNameToTypeCollection
    {
        $variableNamesToType = [];

        // first round to collect assigns
        foreach ((array) $stmtsAware->stmts as $stmt) {
            if (! $stmt instanceof Expression) {
                return new VariableNameToTypeCollection([]);
            }

            if (! $stmt->expr instanceof Assign) {
                continue;
            }

            $variableNameToType = $this->collectFromAssign($stmt->expr);
            if (! $variableNameToType instanceof VariableNameToType) {
                continue;
            }

            $variableNamesToType[] = $variableNameToType;
        }

        return new VariableNameToTypeCollection($variableNamesToType);
    }

    private function collectFromAssign(Assign $assign): ?VariableNameToType
    {
        if (! $assign->expr instanceof MethodCall) {
            return null;
        }

        if (! $assign->var instanceof Variable) {
            return null;
        }

        $variableType = $this->nodeTypeResolver->getType($assign);

        $bareVariableType = TypeCombinator::removeNull($variableType);
        if (! $bareVariableType instanceof ObjectType) {
            return null;
        }

        $variableName = $this->nodeNameResolver->getName($assign->var);
        return new VariableNameToType($variableName, $bareVariableType->getClassName());
    }
}