OperatorRuleHelper - allow benevolent union types that contain numeric types

Author: ondrejmirtes

src/Rules/Operators/OperatorRuleHelper.php

@@ -65,7 +65,12 @@ function (Type $type) use ($acceptedType): bool {
 			return true;
 		}
 
-		return $acceptedType->isSuperTypeOf($type)->yes();
+		$isSuperType = $acceptedType->isSuperTypeOf($type);
+		if ($type instanceof \PHPStan\Type\BenevolentUnionType) {
+			return !$isSuperType->no();
+		}
+
+		return $isSuperType->yes();
 	}
 
 }

tests/Rules/Operators/OperandsInArithmeticAdditionRuleTest.php

@@ -36,6 +36,10 @@ public function testRule(): void
 				'Only numeric types are allowed in +, string given on the right side.',
 				29,
 			],
+			[
+				'Only numeric types are allowed in +, (array<int, string>|false) given on the left side.',
+				110,
+			],
 		]);
 	}
 

tests/Rules/Operators/data/operators.php

@@ -101,3 +101,11 @@ function ($mixed, int $a, string $b) {
 	$mixed + $b;
 	$b + $mixed;
 };
+
+function (array $array, int $int, $mixed) {
+	foreach ($array as $i => $val) {
+		$i + $int;
+	}
+
+	explode($mixed, $mixed) + $int;
+};