AddInstanceofAssertForNullableArgumentRector.php

<?php

declare(strict_types=1);

namespace Rector\PHPUnit\CodeQuality\Rector\ClassMethod;

use PhpParser\Node;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Stmt;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Expression;
use PhpParser\Node\Stmt\Foreach_;
use PhpParser\NodeVisitor;
use PHPStan\Type\ObjectType;
use Rector\PHPUnit\CodeQuality\NodeAnalyser\NullableObjectAssignCollector;
use Rector\PHPUnit\CodeQuality\NodeFactory\AssertMethodCallFactory;
use Rector\PHPUnit\CodeQuality\TypeAnalyzer\MethodCallParameterTypeResolver;
use Rector\PHPUnit\CodeQuality\TypeAnalyzer\SimpleTypeAnalyzer;
use Rector\PHPUnit\CodeQuality\ValueObject\VariableNameToType;
use Rector\PHPUnit\CodeQuality\ValueObject\VariableNameToTypeCollection;
use Rector\PHPUnit\NodeAnalyzer\AssertCallAnalyzer;
use Rector\PHPUnit\NodeAnalyzer\TestsNodeAnalyzer;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\PHPUnit\Tests\CodeQuality\Rector\ClassMethod\AddInstanceofAssertForNullableArgumentRector\AddInstanceofAssertForNullableArgumentRectorTest
 */
final class AddInstanceofAssertForNullableArgumentRector extends AbstractRector
{
    public function __construct(
        private readonly TestsNodeAnalyzer $testsNodeAnalyzer,
        private readonly NullableObjectAssignCollector $nullableObjectAssignCollector,
        private readonly AssertMethodCallFactory $assertMethodCallFactory,
        private readonly MethodCallParameterTypeResolver $methodCallParameterTypeResolver,
        private readonly AssertCallAnalyzer $assertCallAnalyzer,
    ) {
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition(
            'Add explicit instance assert between above nullable object pass',
            [
                new CodeSample(
                    <<<'CODE_SAMPLE'
use PHPUnit\Framework\TestCase;

final class SomeTest extends TestCase
{
    public function test()
    {
        $someObject = $this->getSomeObject();

        $this->process($someObject);
    }

    private function getSomeObject(): ?SomeClass
    {
        if (mt_rand(0, 1)) {
            return new SomeClass();
        }

        return null;
    }

    private function process(SomeClass $someObject): void
    {
        // non-nullable use here
    }
}
CODE_SAMPLE

                    ,
                    <<<'CODE_SAMPLE'
use PHPUnit\Framework\TestCase;

final class SomeTest extends TestCase
{
    public function test()
    {
        $someObject = $this->getSomeObject();
        $this->assertInstanceOf(SomeClass::class, $someObject);

        $this->process($someObject);
    }

    private function getSomeObject(): ?SomeClass
    {
        if (mt_rand(0, 1)) {
            return new SomeClass();
        }

        return null;
    }

    private function process(SomeClass $someObject): void
    {
        // non-nullable use here
    }
}
CODE_SAMPLE
                ),
            ]
        );
    }

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

    /**
     * @param ClassMethod|Foreach_ $node
     */
    public function refactor(Node $node): ?Node
    {
        if (! $this->testsNodeAnalyzer->isInTestClass($node)) {
            return null;
        }

        if ($node->stmts === null || count($node->stmts) < 2) {
            return null;
        }

        $hasChanged = false;
        $variableNameToTypeCollection = $this->nullableObjectAssignCollector->collect($node);

        $next = 0;
        foreach ($node->stmts as $key => $stmt) {
            // already asserted in a previous run? drop the variable to keep the rule idempotent
            $assertedVariableName = $this->matchAssertInstanceOfVariableName($stmt);
            if (is_string($assertedVariableName)) {
                $alreadyAssertedVariableNameToType = $variableNameToTypeCollection->matchByVariableName(
                    $assertedVariableName
                );

                if ($alreadyAssertedVariableNameToType instanceof VariableNameToType) {
                    $variableNameToTypeCollection->remove($alreadyAssertedVariableNameToType);
                }

                continue;
            }

            // has callable on nullable variable of already collected name?
            $matchedNullableVariableNameToType = $this->matchedNullableArgumentNameToType(
                $stmt,
                $variableNameToTypeCollection
            );

            if (! $matchedNullableVariableNameToType instanceof VariableNameToType) {
                continue;
            }

            // adding type here + popping the variable name out
            $assertInstanceOfExpression = $this->assertMethodCallFactory->createAssertInstanceOf(
                $matchedNullableVariableNameToType
            );
            array_splice($node->stmts, $key + $next, 0, [$assertInstanceOfExpression]);

            // remove variable name from nullable ones
            $hasChanged = true;

            // from now on, the variable is not nullable, remove to avoid double asserts
            $variableNameToTypeCollection->remove($matchedNullableVariableNameToType);

            ++$next;
        }

        if (! $hasChanged) {
            return null;
        }

        return $node;
    }

    private function matchedNullableArgumentNameToType(
        Stmt $stmt,
        VariableNameToTypeCollection $variableNameToTypeCollection
    ): ?VariableNameToType {
        $matchedNullableVariableNameToType = null;

        $this->traverseNodesWithCallable($stmt, function (Node $node) use (
            $variableNameToTypeCollection,
            &$matchedNullableVariableNameToType
        ): ?int {
            if (! $node instanceof MethodCall) {
                return null;
            }

            if ($node->isFirstClassCallable()) {
                return null;
            }

            // avoid double null on assert
            if ($this->assertCallAnalyzer->isAssertMethodCall($node)) {
                return null;
            }

            $classMethodParameterTypes = $this->methodCallParameterTypeResolver->resolve($node);

            foreach ($node->getArgs() as $position => $arg) {
                if (! $arg->value instanceof Variable) {
                    continue;
                }

                $variableType = $this->getType($arg->value);
                if (! SimpleTypeAnalyzer::isNullableType($variableType)) {
                    return null;
                }

                // should not happen
                if (! isset($classMethodParameterTypes[$position])) {
                    return null;
                }

                $variableName = $this->getName($arg->value);
                if (! is_string($variableName)) {
                    return null;
                }

                $matchedNullableVariableNameToType = $variableNameToTypeCollection->matchByVariableName($variableName);

                // is object type required?
                if (! $classMethodParameterTypes[$position] instanceof ObjectType) {
                    return null;
                }

                return NodeVisitor::STOP_TRAVERSAL;
            }

            return null;
        });

        return $matchedNullableVariableNameToType;
    }

    private function matchAssertInstanceOfVariableName(Stmt $stmt): ?string
    {
        if (! $stmt instanceof Expression) {
            return null;
        }

        if (! $stmt->expr instanceof MethodCall) {
            return null;
        }

        $methodCall = $stmt->expr;
        if (! $this->isName($methodCall->name, 'assertInstanceOf')) {
            return null;
        }

        $args = $methodCall->getArgs();
        if (! isset($args[1])) {
            return null;
        }

        if (! $args[1]->value instanceof Variable) {
            return null;
        }

        $variableName = $this->getName($args[1]->value);
        if (! is_string($variableName)) {
            return null;
        }

        return $variableName;
    }
}