Use count() return type in ObjectType::getArraySize()

src/Type/ObjectType.php

@@ -946,7 +946,7 @@ public function getArraySize(): Type
 			return new ErrorType();
 		}
 
-		return IntegerRangeType::fromInterval(0, null);
+		return RecursionGuard::run($this, fn (): Type => $this->getMethod('count', new OutOfClassScope())->getOnlyVariant()->getReturnType());
 	}
 
 	public function getIterableKeyType(): Type

tests/PHPStan/Analyser/nsrt/bug-7607.php

@@ -30,7 +30,7 @@ public function blank($value)
 			return false;
 		}
 
-		if ($value instanceof Countable) {
+		if ($value instanceof \Countable) {
 			return count($value) === 0;
 		}
 

tests/PHPStan/Analyser/nsrt/countable.php

@@ -15,9 +15,31 @@ static public function doFoo() {
 	}
 }
 
+class Bar implements \Countable {
+
+	/**
+	 * @return -1
+	 */
+	public function count() : int {
+		return -1;
+	}
+
+	static public function doBar() {
+		$bar = new Bar();
+		assertType('-1', $bar->count());
+	}
+}
+
 class NonCountable {}
 
+function doNonCountable() {
+	assertType('*ERROR*', count(new NonCountable()));
+}
+
 function doFoo() {
 	assertType('int<0, max>', count(new Foo()));
-	assertType('*ERROR*', count(new NonCountable()));
+}
+
+function doBar() {
+	assertType('-1', count(new Bar()));
 }