init3

Feature3.py

+from abc import ABC, abstractmethod
+import unittest
+
+class IStringCalculator(ABC):
+    @abstractmethod
+    def add(self, numbers: str) -> int:
+        pass
+
+class StringCalculator(IStringCalculator):
+    def add(self, numbers: str) -> int:
+        if not numbers:
+            return 0
+        
+        # Ersetze Zeilenumbrüche durch Kommas und teile die Eingabe nach Kommas
+        numbers = numbers.replace("\n", ",")
+        
+        # Splitte die Zahlen und prüfe auf negative Zahlen
+        nums = numbers.split(',')
+        negatives = [num for num in nums if int(num) < 0]
+        
+        if negatives:
+            # Wenn negative Zahlen vorhanden sind, werfe eine Ausnahme
+            raise ValueError(f"Negatives not allowed: {', '.join(negatives)}")
+        
+        # Berechne die Summe der positiven Zahlen
+        return sum(map(int, nums))
+
+class TestStringCalculator(unittest.TestCase):
+    def setUp(self):
+        self.calculator = StringCalculator()
+    
+    def test_empty_string(self):
+        self.assertEqual(self.calculator.add(""), 0)
+    
+    def test_single_number(self):
+        self.assertEqual(self.calculator.add("1"), 1)
+    
+    def test_two_numbers(self):
+        self.assertEqual(self.calculator.add("1,2"), 3)
+    
+    def test_multiple_numbers(self):
+        self.assertEqual(self.calculator.add("1,2,3,4,5"), 15)
+    
+    def test_numbers_with_newline(self):
+        self.assertEqual(self.calculator.add("1\n2,3"), 6)
+    
+    def test_numbers_with_multiple_newlines(self):
+        self.assertEqual(self.calculator.add("1\n2\n3\n4\n5"), 15)
+    
+    def test_negative_number(self):
+        with self.assertRaises(ValueError) as context:
+            self.calculator.add("1,-2,3")
+        self.assertEqual(str(context.exception), "Negatives not allowed: -2")
+    
+    def test_multiple_negative_numbers(self):
+        with self.assertRaises(ValueError) as context:
+            self.calculator.add("1,-2,-3,4")
+        self.assertEqual(str(context.exception), "Negatives not allowed: -2, -3")
+
+if __name__ == "__main__":
+    unittest.main()