Add CA4 second question

Baloot1/Reports/Extras/CA4/main.py

@@ -0,0 +1,6 @@
+def calculate_total_cost(quantity, unit_price, discount):
+    if quantity <= 0 or unit_price <= 0:
+        return "Invalid input"
+    else:
+        total_cost = quantity * unit_price * (1 - discount)
+        return total_cost

Baloot1/Reports/Extras/CA4/test.py

@@ -0,0 +1,41 @@
+import unittest
+
+from main import calculate_total_cost
+
+INVALID_INPUT = "Invalid input"
+
+A = [-1, 0, 1, 2]
+B = [-1, 0, 1]
+C = [-1, 0, 0.5, 1, 2]
+
+
+class TestCalculateTotalCost(unittest.TestCase):
+  def test_invalid_inputs_should_fail(self):
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[0], B[0], C[0]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[0], B[2], C[1]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[0], B[1], C[2]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[0], B[0], C[3]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[0], B[0], C[4]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[1], B[1], C[0]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[1], B[0], C[1]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[1], B[2], C[2]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[1], B[1], C[3]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[1], B[1], C[4]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[2], B[1], C[1]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[2], B[0], C[2]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[3], B[0], C[0]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[3], B[1], C[4]))
+
+  def test_invalid_discount_should_fail(self):  # This case is not covered in the main.py
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[2], B[2], C[0]))
+    self.assertEqual(INVALID_INPUT, calculate_total_cost(A[2], B[2], C[4]))
+
+  def test_valid_inputs_should_pass(self):
+    self.assertEqual(0, calculate_total_cost(A[2], B[2], C[3]))
+    self.assertEqual(2, calculate_total_cost(A[3], B[2], C[1]))
+    self.assertEqual(1, calculate_total_cost(A[3], B[2], C[2]))
+    self.assertEqual(0, calculate_total_cost(A[3], B[2], C[3]))
+
+
+if __name__ == '__main__':
+  unittest.main()