errors on recursive count

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -369,6 +369,7 @@ public function specifyTypesInCondition(
 				$subtractedType = $scope->getType($expr->right->right);
 				if (
 					$countArgType->isList()->yes()
+					&& $this->isNormalCountCall($expr->right->left, $countArgType, $scope)->yes()
 					&& IntegerRangeType::fromInterval(1, null)->isSuperTypeOf($subtractedType)->yes()
 				) {
 					$arrayArg = $expr->right->left->getArgs()[0]->value;
@@ -1239,6 +1240,16 @@ public function specifyTypesInCondition(
 		return (new SpecifiedTypes([], []))->setRootExpr($expr);
 	}
 
+	private function isNormalCountCall(FuncCall $countFuncCall, Type $typeToCount, Scope $scope): TrinaryLogic
+	{
+		if (count($countFuncCall->getArgs()) === 1) {
+			return TrinaryLogic::createYes();
+		}
+
+		$mode = $scope->getType($countFuncCall->getArgs()[1]->value);
+		return (new ConstantIntegerType(COUNT_NORMAL))->isSuperTypeOf($mode)->result->or($typeToCount->getIterableValueType()->isArray()->negate());
+	}
+
 	private function specifyTypesForCountFuncCall(
 		FuncCall $countFuncCall,
 		Type $type,
@@ -1248,18 +1259,11 @@ private function specifyTypesForCountFuncCall(
 		Expr $rootExpr,
 	): ?SpecifiedTypes
 	{
-		if (count($countFuncCall->getArgs()) === 1) {
-			$isNormalCount = TrinaryLogic::createYes();
-		} else {
-			$mode = $scope->getType($countFuncCall->getArgs()[1]->value);
-			$isNormalCount = (new ConstantIntegerType(COUNT_NORMAL))->isSuperTypeOf($mode)->result->or($type->getIterableValueType()->isArray()->negate());
-		}
-
 		$isConstantArray = $type->isConstantArray();
 		$isList = $type->isList();
 		$oneOrMore = IntegerRangeType::fromInterval(1, null);
 		if (
-			!$isNormalCount->yes()
+			!$this->isNormalCountCall($countFuncCall, $type, $scope)->yes()
 			|| (!$isConstantArray->yes() && !$isList->yes())
 			|| !$oneOrMore->isSuperTypeOf($sizeType)->yes()
 			|| $sizeType->isSuperTypeOf($type->getArraySize())->yes()

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -1198,6 +1198,10 @@ public function testBug13770(): void
 				'Offset -5|int<0, max> might not exist on list<int>.',
 				190,
 			],
+			[
+				'Offset int<0, max> might not exist on list<mixed>.',
+				203,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Arrays/data/bug-13770.php

@@ -192,4 +192,17 @@ public function errorsBecauseMaybeTooSmall(array $array, int $index): int
 
 		return 0;
 	}
+
+	/**
+	 * @param list<mixed> $array
+	 * @param 0|positive-int $index
+	 */
+	public function errorsOnRecursiveCount(array $array, int $index): int
+	{
+		if ($index <= count($array, COUNT_RECURSIVE) - 5) {
+			return $array[$index];
+		}
+
+		return 0;
+	}
 }