Fix

Author: VincentLanglet

src/Reflection/InitializerExprTypeResolver.php

@@ -65,6 +65,8 @@
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\TypeWithClassName;
 use PHPStan\Type\UnionType;
+use PHPStan\Type\VerbosityLevel;
+
 use function array_keys;
 use function array_merge;
 use function assert;
@@ -1479,7 +1481,7 @@ private function resolveCommonMath(Expr\BinaryOp $expr, Type $leftType, Type $ri
 				return $union->toNumber();
 			}
 
-			return $this->integerRangeMath($leftType, $expr, $rightType);
+			return $this->integerRangeMath($leftNumberType, $expr, $rightNumberType);
 		}
 
 		$specifiedTypes = $this->callOperatorTypeSpecifyingExtensions($expr, $leftType, $rightType);
@@ -1532,7 +1534,6 @@ private function resolveCommonMath(Expr\BinaryOp $expr, Type $leftType, Type $ri
 	/**
 	 * @param ConstantIntegerType|IntegerRangeType $range
 	 * @param BinaryOp\Div|BinaryOp\Minus|BinaryOp\Mul|BinaryOp\Plus $node
-	 * @param IntegerRangeType|ConstantIntegerType|UnionType $operand
 	 */
 	private function integerRangeMath(Type $range, BinaryOp $node, Type $operand): Type
 	{
@@ -1549,8 +1550,9 @@ private function integerRangeMath(Type $range, BinaryOp $node, Type $operand): T
 			$unionParts = [];
 
 			foreach ($operand->getTypes() as $type) {
-				if ($type instanceof IntegerRangeType || $type instanceof ConstantIntegerType) {
-					$unionParts[] = $this->integerRangeMath($range, $node, $type);
+				$numberType = $type->toNumber();
+				if ($numberType instanceof IntegerRangeType || $numberType instanceof ConstantIntegerType) {
+					$unionParts[] = $this->integerRangeMath($range, $node, $numberType);
 				} else {
 					$unionParts[] = $type->toNumber();
 				}
@@ -1564,6 +1566,11 @@ private function integerRangeMath(Type $range, BinaryOp $node, Type $operand): T
 			return $union->toNumber();
 		}
 
+		$operand = $operand->toNumber();
+		if (!$operand instanceof IntegerRangeType && !$operand instanceof ConstantIntegerType) {
+			return $operand;
+		}
+
 		if ($operand instanceof IntegerRangeType) {
 			$operandMin = $operand->getMin();
 			$operandMax = $operand->getMax();

tests/PHPStan/Analyser/data/bug-8803.php

@@ -11,10 +11,12 @@ public function sayHello(): void
 		$from = new \DateTimeImmutable('2023-01-30');
 		for ($offset = 1; $offset <= 14; $offset++) {
 			$value = $from->format('N') + $offset;
+			$value2 = $offset + $from->format('N');
 
 			assertType("'1'|'2'|'3'|'4'|'5'|'6'|'7'", $from->format('N'));
 			assertType('int<1, 14>', $offset);
 			assertType('int<2, 21>', $value);
+			assertType('int<2, 21>', $value2);
 		}
 	}