Umsetzung der Testszenarien von Feature2

src/stringcalculator.py

 from src.interfaces import IStringCalculator
+import re
+
 
 class StringCalculator(IStringCalculator):
     def add(self, numbers: str) -> int:
         if not numbers:
             return 0
-        return sum(map(int, numbers.split(',')))
\ No newline at end of file
+
+        # Erlaubt Kommas und Zeilenumbrüche als Trennzeichen
+        tokens = re.split(r"[,\n]", numbers)
+
+        return sum(map(int, tokens))
\ No newline at end of file

tests/test_stringclaculator.py

@@ -31,6 +31,10 @@ class TestStringCalculator(unittest.TestCase):
         self.assertEqual(self.calculator.add("1,2,3"), 6)
         self.assertEqual(self.calculator.add("10,20,30,40"), 100)
 
+    def test_add_with_newline_separator(self):
+        self.assertEqual(self.calculator.add("1\n2,3"), 6)
+        self.assertEqual(self.calculator.add("10\n20\n30"), 60)
+
 if __name__ == "__main__":
     unittest.main()