keepVoidType solution for GNSR

Author: ondrejmirtes

build/PHPStan/Build/ScopeGetTypeInGeneratorNamespaceRule.php

@@ -69,7 +69,7 @@ public function processNode(Node $node, Scope $scope): array
 			$invalidNamespace,
 		);
 
-		if (in_array($methodReflection->getName(), ['getType', 'getNativeType'], true)) {
+		if (in_array($methodReflection->getName(), ['getType', 'getNativeType', 'getKeepVoidType'], true)) {
 			return [
 				RuleErrorBuilder::message($message)
 					->identifier('phpstan.scopeGetType')

src/Analyser/Generator/ExprAnalysisResult.php

@@ -9,6 +9,8 @@
 final class ExprAnalysisResult
 {
 
+	public readonly Type $keepVoidType;
+
 	/**
 	 * @param InternalThrowPoint[] $throwPoints
 	 * @param ImpurePoint[] $impurePoints
@@ -23,8 +25,10 @@ public function __construct(
 		public readonly array $impurePoints,
 		public readonly SpecifiedTypes $specifiedTruthyTypes,
 		public readonly SpecifiedTypes $specifiedFalseyTypes,
+		?Type $keepVoidType = null,
 	)
 	{
+		$this->keepVoidType = $keepVoidType ?? $type;
 	}
 
 }

src/Analyser/Generator/ExprHandler/ArrowFunctionHandler.php

@@ -187,7 +187,7 @@ private function getArrowFunctionScope(Stmt $stmt, GeneratorScope $scope, ArrowF
 				new VoidType(),
 			]);
 		} else {
-			$returnType = $arrowFunctionExprResult->type; // todo keep void
+			$returnType = $arrowFunctionExprResult->keepVoidType;
 			if ($node->returnType !== null) {
 				$nativeReturnType = $scope->getFunctionType($node->returnType, false, false);
 				$returnType = GeneratorScope::intersectButNotNever($nativeReturnType, $returnType);

src/Analyser/Generator/ExprHandler/MethodCallHelper.php

@@ -43,7 +43,6 @@ public function methodCallReturnType(
 	): Generator
 	{
 		if ($normalizedMethodCall === null) {
-			//return $this->transformVoidToNull($parametersAcceptor->getReturnType(), $methodCall);
 			return $parametersAcceptor->getReturnType();
 		}
 
@@ -83,11 +82,9 @@ public function methodCallReturnType(
 		}
 
 		if (count($resolvedTypes) > 0) {
-			//return $this->transformVoidToNull(TypeCombinator::union(...$resolvedTypes), $methodCall);
 			return TypeCombinator::union(...$resolvedTypes);
 		}
 
-		//return $this->transformVoidToNull($parametersAcceptor->getReturnType(), $methodCall);
 		return $parametersAcceptor->getReturnType();
 	}
 

src/Analyser/Generator/ExprHandler/StaticCallHandler.php

@@ -61,6 +61,7 @@ public function __construct(
 		private readonly DynamicThrowTypeExtensionProvider $dynamicThrowTypeExtensionProvider,
 		private readonly NullsafeShortCircuitingHelper $nullsafeShortCircuitingHelper,
 		private readonly MethodCallHelper $methodCallHelper,
+		private readonly VoidTypeHelper $voidTypeHelper,
 		#[AutowiredParameter(ref: '%exceptions.implicitThrows%')]
 		private readonly bool $implicitThrows,
 	)
@@ -262,9 +263,10 @@ public function analyseExpr(Stmt $stmt, Expr $expr, GeneratorScope $scope, Expre
 		}
 
 		return new ExprAnalysisResult(
-			$methodReturnType,
-			$nativeMethodReturnType,
-			$scope,
+			$this->voidTypeHelper->transformVoidToNull($methodReturnType),
+			$this->voidTypeHelper->transformVoidToNull($nativeMethodReturnType),
+			keepVoidType: $methodReturnType,
+			scope: $scope,
 			hasYield: $hasYield || $argsResult->hasYield,
 			isAlwaysTerminating: ($methodReturnType instanceof NeverType && $methodReturnType->isExplicit()) || $argsResult->isAlwaysTerminating,
 			throwPoints: array_merge($throwPoints, $argsResult->throwPoints),
@@ -392,9 +394,10 @@ private function processClassExpr(Stmt $stmt, StaticCall $expr, Expr $class, Gen
 		$scope = $argsResult->scope;
 
 		return new ExprAnalysisResult(
-			$methodReturnType,
-			$nativeMethodReturnType,
-			$scope,
+			$this->voidTypeHelper->transformVoidToNull($methodReturnType),
+			$this->voidTypeHelper->transformVoidToNull($nativeMethodReturnType),
+			keepVoidType: $methodReturnType,
+			scope: $scope,
 			hasYield: $hasYield || $argsResult->hasYield,
 			isAlwaysTerminating: $isAlwaysTerminating || $argsResult->isAlwaysTerminating,
 			throwPoints: array_merge($throwPoints, $argsResult->throwPoints),

src/Analyser/Generator/ExprHandler/VoidTypeHelper.php

@@ -0,0 +1,31 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Analyser\Generator\ExprHandler;
+
+use PHPStan\DependencyInjection\AutowiredService;
+use PHPStan\Type\IntersectionType;
+use PHPStan\Type\NullType;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeTraverser;
+use PHPStan\Type\UnionType;
+
+#[AutowiredService]
+final class VoidTypeHelper
+{
+
+	public function transformVoidToNull(Type $type): Type
+	{
+		return TypeTraverser::map($type, static function (Type $type, callable $traverse): Type {
+			if ($type instanceof UnionType || $type instanceof IntersectionType) {
+				return $traverse($type);
+			}
+
+			if ($type->isVoid()->yes()) {
+				return new NullType();
+			}
+
+			return $type;
+		});
+	}
+
+}

src/Analyser/Generator/GeneratorNodeScopeResolver.php

@@ -541,7 +541,7 @@ private function analyseExprForType(ExprAnalysisResultStorage $storage, Expr $ex
 		$result = $storage->findExprAnalysisResult($expr);
 		if ($result !== null) {
 			yield from [];
-			return new TypeExprResult($result->type, $result->nativeType);
+			return new TypeExprResult($result->type, $result->nativeType, $result->keepVoidType);
 		}
 
 		throw new ShouldNotHappenException('Not yet implemented - park expr request for type until later when it has been analysed');

src/Analyser/Generator/GeneratorScope.php

@@ -2473,8 +2473,11 @@ private function promoteNativeTypes(): self
 
 	public function getKeepVoidType(Expr $node): Type
 	{
-		// TODO: Implement getKeepVoidType() method.
-		throw new ShouldNotHappenException('Not implemented yet');
+		return TypeUtils::resolveLateResolvableTypes(
+			Fiber::suspend(
+				new ExprAnalysisRequest(new Node\Stmt\Expression($node), $node, $this, ExpressionContext::createTopLevel(), new NoopNodeCallback()),
+			)->keepVoidType,
+		);
 	}
 
 	/**

src/Analyser/Generator/TypeExprResult.php

@@ -10,6 +10,7 @@ final class TypeExprResult
 	public function __construct(
 		public readonly Type $type,
 		public readonly Type $nativeType,
+		public readonly Type $keepVoidType,
 	)
 	{
 	}

tests/PHPStan/Build/ScopeGetTypeInGeneratorNamespaceRuleTest.php

@@ -39,21 +39,26 @@ public function testRule(): void
 				49,
 				'Use yield new TypeExprRequest instead.',
 			],
+			[
+				'Scope::getKeepVoidType() cannot be called in PHPStan\Analyser\Generator namespace.',
+				50,
+				'Use yield new TypeExprRequest instead.',
+			],
 			[
 				'Scope::filterByTruthyValue() cannot be called in PHPStan\Analyser\Generator namespace.',
-				59,
+				60,
 			],
 			[
 				'Scope::filterByFalseyValue() cannot be called in PHPStan\Analyser\Generator namespace.',
-				60,
+				61,
 			],
 			[
 				'Scope::filterByTruthyValue() cannot be called in PHPStan\Analyser\Generator namespace.',
-				65,
+				66,
 			],
 			[
 				'Scope::filterByFalseyValue() cannot be called in PHPStan\Analyser\Generator namespace.',
-				66,
+				67,
 			],
 		]);
 	}