Merge branch 'issue/7'

Author: rambasnet

demo-assignments/A2-ABC/egypt/egypt_singleton.py

@@ -14,17 +14,23 @@ class Solution(Kattis):
     """
     _instance: "Solution" | None = None
 
+    def __new__(cls, input_source: Any = sys.stdin) -> Solution:
+        """Creates a new instance of the class
+
+        Args:
+            input_source (Any): input source
+
+        Returns:
+            Solution: class instance
+        """
+        if not cls._instance:
+            cls._instance = super().__new__(cls)
+        return cls._instance
+
     def __init__(self, input_source: Any = sys.stdin) -> None:
         """Constructor
         """
-        if Solution._instance:
-            raise NameError(
-                "Cannot create multiple instances of \
-                a singleton class Solution")
-
-        super().__init__(input_source)
-        Solution._instance = self
-        # self._input_source: Any = input_source
+        Kattis.__init__(self, input_source)
         self._data: List[List[int]] = []
         self._triangles: List[Triangle] = []
         self._answer: List[str] = []
@@ -86,12 +92,6 @@ def print_answer(self) -> None:
         """
         sys.stdout.write(self.answer)
 
-    @classmethod
-    def reset_instance(cls) -> None:
-        """Resets the instance
-        """
-        cls._instance = None
-
     @staticmethod
     def main() -> None:
         """Main function to run the solution

demo-assignments/A2-ABC/egypt/tests/test_egypt_singleton.py

@@ -22,7 +22,6 @@ class TestSolution(unittest.TestCase):
     """
 
     def tearDown(self) -> None:
-        Solution.reset_instance()
         return super().tearDown()
 
     @patch('sys.stdout', new_callable=StringIO)
@@ -89,7 +88,6 @@ def test_main(self, mock_stdout: StringIO) -> None:
             Solution.main()
             expected: str = 'wrong\nwrong\nwrong\nright\n'
             self.assertEqual(mock_stdout.getvalue(), expected)
-            # Solution.reset_instance()
 
     def test_data(self) -> None:
         """Tests data property
@@ -99,35 +97,14 @@ def test_data(self) -> None:
             sol = Solution(sys.stdin)
             self.assertEqual(
                 sol.data, [[2, 3, 4], [20, 50, 62], [3, 4, 7]])
-            # Solution.reset_instance()
 
     def test_singleton(self) -> None:
-        """Tests singleton property
-        """
-        data = '2 3 4\n20 50 62\n3 4 7\n0 0 0\n'
-        with patch('sys.stdin', StringIO(data)):
-            _ = Solution(sys.stdin)
-            with self.assertRaises(NameError):
-                _ = Solution(sys.stdin)
-            # self.assertIs(instance1, instance2)
-            # Solution.reset_instance()
-
-    def test_get_instance(self) -> None:
         """Tests get_instance method
         """
-        data = '2 3 4\n20 50 62\n3 4 7\n0 0 0\n'
-        with patch('sys.stdin', StringIO(data)):
-            instance1 = Solution(sys.stdin)
-            instance2 = Solution.get_instance()
-            self.assertIs(instance1, instance2)
-
-    def test_set_instance(self) -> None:
-        """Tests set_instance method
-        """
-        data = '2 3 4\n20 50 62\n3 4 7\n0 0 0\n'
-        with patch('sys.stdin', StringIO(data)):
+        data1 = '2 3 4\n20 50 62\n3 4 7\n0 0 0\n'
+        data2 = '20 30 40\n200 500 620\n30 40 70\n0 0 0\n'
+        with patch('sys.stdin', StringIO(data1)):
             instance1 = Solution(sys.stdin)
-            instance2 = Solution.get_instance()
-            self.assertIs(instance1, instance2)
-            Solution.reset_instance()
-            self.assertIsNone(Solution._instance)
+            with patch('sys.stdin', StringIO(data2)):
+                instance2 = Solution(sys.stdin)
+                self.assertIs(instance1, instance2)