More precise types after assignment when strict-types=0

Author: staabm

src/Analyser/NodeScopeResolver.php

@@ -5647,6 +5647,12 @@ static function (): void {
 								TypeCombinator::intersect($assignedExprType->toCoercedArgumentType(true), $propertyNativeType),
 								TypeCombinator::intersect($assignedNativeType->toCoercedArgumentType(true), $propertyNativeType),
 							);
+						} elseif (TypeCombinator::containsNull($propertyNativeType) && !TypeCombinator::containsNull($assignedNativeType)) {
+							$scope = $scope->assignExpression(
+								$var,
+								TypeCombinator::removeNull($propertyReflection->hasPhpDocType() ? $propertyReflection->getPhpDocType() : $propertyNativeType),
+								TypeCombinator::removeNull($propertyNativeType),
+							);
 						}
 					} else {
 						$scope = $scope->assignExpression($var, $assignedExprType, $scope->getNativeType($assignedExpr));
@@ -5735,6 +5741,12 @@ static function (): void {
 								TypeCombinator::intersect($assignedExprType->toCoercedArgumentType(true), $propertyNativeType),
 								TypeCombinator::intersect($assignedNativeType->toCoercedArgumentType(true), $propertyNativeType),
 							);
+						} elseif (TypeCombinator::containsNull($propertyNativeType) && !TypeCombinator::containsNull($assignedNativeType)) {
+							$scope = $scope->assignExpression(
+								$var,
+								TypeCombinator::removeNull($propertyReflection->hasPhpDocType() ? $propertyReflection->getPhpDocType() : $propertyNativeType),
+								TypeCombinator::removeNull($propertyNativeType),
+							);
 						}
 					} else {
 						$scope = $scope->assignExpression($var, $assignedExprType, $scope->getNativeType($assignedExpr));

tests/PHPStan/Analyser/nsrt/remember-non-nullable-property-non-strict.php

@@ -86,3 +86,41 @@ public function doFoo(): void {
 function getInt(): int {
 	return 1;
 }
+
+
+interface ObjectDataMapper
+{
+	/**
+	 * @template OutType of object
+	 *
+	 * @param literal-string&class-string<OutType> $class
+	 * @param mixed                                $data
+	 *
+	 * @return OutType
+	 *
+	 * @throws DataMappingException
+	 */
+	public function map(string $class, $data): object;
+}
+
+final class ApiProductController
+{
+
+	protected ?SearchProductsVM $searchProductsVM = null;
+
+	protected static ?SearchProductsVM $searchProductsVMStatic = null;
+
+	public function search(ObjectDataMapper $dataMapper): void
+	{
+		$this->searchProductsVM = $dataMapper->map(SearchProductsVM::class, $_REQUEST);
+		assertType('RememberNonNullablePropertyWhenStrictTypesDisabled\SearchProductsVM', $this->searchProductsVM);
+	}
+
+	public function searchStatic(ObjectDataMapper $dataMapper): void
+	{
+		self::$searchProductsVMStatic = $dataMapper->map(SearchProductsVM::class, $_REQUEST);
+		assertType('RememberNonNullablePropertyWhenStrictTypesDisabled\SearchProductsVM', self::$searchProductsVMStatic);
+	}
+}
+
+class SearchProductsVM {}