Added four tests for update_std_dev()

spotifyvis/tests.py

@@ -1,3 +1,54 @@
 from django.test import TestCase
-
+from .views import update_std_dev
+import math
 # Create your tests here.
+
+class UpdateStdDevTest(TestCase):
+
+    def test_two_data_points(self):
+        """
+        tests if update_std_dev behaves correctly for two data points
+        """
+        cur_mean = 5
+        cur_std_dev = 0
+
+        new_mean, new_std_dev = update_std_dev(cur_mean, cur_std_dev, 10, 2)
+
+        self.assertTrue(math.isclose(new_mean, 7.5, rel_tol=0.01))
+        self.assertTrue(math.isclose(new_std_dev, 3.5355, rel_tol=0.01))
+
+    def test_three_data_points(self):
+        """
+        tests if update_std_dev behaves correctly for three data points
+        """
+        cur_mean = 7.5
+        cur_std_dev = 3.5355
+
+        new_mean, new_std_dev = update_std_dev(cur_mean, cur_std_dev, 15, 3)
+
+        self.assertTrue(math.isclose(new_mean, 10, rel_tol=0.01))
+        self.assertTrue(math.isclose(new_std_dev, 5, rel_tol=0.01))
+    
+    def test_four_data_points(self):
+        """
+        tests if update_std_dev behaves correctly for four data points
+        """
+        cur_mean = 10 
+        cur_std_dev = 5 
+
+        new_mean, new_std_dev = update_std_dev(cur_mean, cur_std_dev, 20, 4) 
+        self.assertTrue(math.isclose(new_mean, 12.5, rel_tol=0.01))
+        self.assertTrue(math.isclose(new_std_dev, 6.455, rel_tol=0.01))
+
+
+
+    def test_five_data_points(self):
+        """
+        tests if update_std_dev behaves correctly for five data points
+        """
+        cur_mean = 12.5
+        cur_std_dev = 6.455 
+
+        new_mean, new_std_dev = update_std_dev(cur_mean, cur_std_dev, 63, 5) 
+        self.assertTrue(math.isclose(new_mean, 22.6, rel_tol=0.01)) 
+        self.assertTrue(math.isclose(new_std_dev, 23.2658, rel_tol=0.01))