Fix internal error when assigning new DatePeriod into property

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -5899,28 +5899,31 @@ private function exactInstantiation(New_ $node, string $className): ?Type
 
 		$assignedToProperty = $node->getAttribute(NewAssignedToPropertyVisitor::ATTRIBUTE_NAME);
 		if ($assignedToProperty !== null) {
-			$constructorVariant = $constructorMethod->getOnlyVariant();
-			$classTemplateTypes = $classReflection->getTemplateTypeMap()->getTypes();
-			$originalClassTemplateTypes = $classTemplateTypes;
-			foreach ($constructorVariant->getParameters() as $parameter) {
-				TypeTraverser::map($parameter->getType(), static function (Type $type, callable $traverse) use (&$classTemplateTypes): Type {
-					if ($type instanceof TemplateType && array_key_exists($type->getName(), $classTemplateTypes)) {
-						$classTemplateType = $classTemplateTypes[$type->getName()];
-						if ($classTemplateType instanceof TemplateType && $classTemplateType->getScope()->equals($type->getScope())) {
-							unset($classTemplateTypes[$type->getName()]);
+			$constructorVariants = $constructorMethod->getVariants();
+			if (count($constructorVariants) === 1) {
+				$constructorVariant = $constructorVariants[0];
+				$classTemplateTypes = $classReflection->getTemplateTypeMap()->getTypes();
+				$originalClassTemplateTypes = $classTemplateTypes;
+				foreach ($constructorVariant->getParameters() as $parameter) {
+					TypeTraverser::map($parameter->getType(), static function (Type $type, callable $traverse) use (&$classTemplateTypes): Type {
+						if ($type instanceof TemplateType && array_key_exists($type->getName(), $classTemplateTypes)) {
+							$classTemplateType = $classTemplateTypes[$type->getName()];
+							if ($classTemplateType instanceof TemplateType && $classTemplateType->getScope()->equals($type->getScope())) {
+								unset($classTemplateTypes[$type->getName()]);
+							}
+							return $type;
 						}
-						return $type;
-					}
 
-					return $traverse($type);
-				});
-			}
+						return $traverse($type);
+					});
+				}
 
-			if (count($classTemplateTypes) === count($originalClassTemplateTypes)) {
-				$propertyType = TypeCombinator::removeNull($this->getType($assignedToProperty));
-				$nonFinalObjectType = $isStatic ? new StaticType($nonFinalClassReflection) : new ObjectType($resolvedClassName, classReflection: $nonFinalClassReflection);
-				if ($nonFinalObjectType->isSuperTypeOf($propertyType)->yes()) {
-					return $propertyType;
+				if (count($classTemplateTypes) === count($originalClassTemplateTypes)) {
+					$propertyType = TypeCombinator::removeNull($this->getType($assignedToProperty));
+					$nonFinalObjectType = $isStatic ? new StaticType($nonFinalClassReflection) : new ObjectType($resolvedClassName, classReflection: $nonFinalClassReflection);
+					if ($nonFinalObjectType->isSuperTypeOf($propertyType)->yes()) {
+						return $propertyType;
+					}
 				}
 			}
 		}

tests/PHPStan/Analyser/nsrt/date-period-return-types.php

@@ -1,5 +1,11 @@
 <?php declare(strict_types=1);
 
+namespace DatePeriodReturnTypes;
+
+use DateInterval;
+use DatePeriod;
+use DateTime;
+use DateTimeImmutable;
 use function PHPStan\Testing\assertType;
 
 $start = new DateTime('2012-07-01');
@@ -38,3 +44,13 @@
 assertType(\DatePeriod::class, $datePeriod);
 assertType(\DateTimeInterface::class . '|null', $datePeriod->getEndDate());
 assertType('int|null', $datePeriod->getRecurrences());
+
+class Foo
+{
+	private DatePeriod $period;
+
+	public function doFoo(DateTimeImmutable $fromDate, DateTimeImmutable $toDate): void
+	{
+		$this->period = new DatePeriod($fromDate, new DateInterval('P1D'), $toDate->modify('+1 day'));
+	}
+}