test/test_vector.py

@@ -33,6 +33,14 @@ class TestVector(unittest.TestCase):
         self.assertIsInstance(v3, Vector)
         self.assertEqual(v3.x, v1.x + v2.x)
 
+    def test_abs(self):
+        v1 = Vector(0, 0, 0)
+        v2 = Vector(1, 2, 2)
+        v3 = Vector(1, -2, 2)
+        self.assertEqual(v1.abs(), 0)
+        self.assertEqual(v2.abs(), 3)
+        self.assertEqual(v2.abs(), v3.abs())
+        
     def test_dot_failure(self):
         with self.assertRaises(ValueError):
             v1 = Vector(1, 2, 3)