added unittest for addition

ramalho · ramalho · commit c21af3003462 · 2016-06-09T15:26:20.000-03:00
diff --git a/exercises/vector/solution/vector.py b/exercises/vector/solution/vector.py
@@ -63,9 +63,9 @@ def __add__(self, other):
         try:
             if len(self) != len(other):
                 raise ValueError('Only vectors of same length may be added.')
+            return Vector(a + b for a, b in zip(self, other))
         except TypeError:
             return NotImplemented
-        return Vector(a + b for a, b in zip(self, other))
 
     def __radd__(self, other):
         return self + other
diff --git a/exercises/vector/test_xunit_vector_add.py b/exercises/vector/test_xunit_vector_add.py
@@ -0,0 +1,31 @@
+import unittest
+
+from vector import Vector
+
+class TestAddition(unittest.TestCase):
+
+
+    def setUp(self):
+        self.v2d = Vector([1, 2])
+        
+
+    def test_2d_vector_addition(self):
+        v = Vector([3, 4]) + self.v2d
+        self.assertEqual(v, Vector([4, 6]))
+
+
+    def test_mismatched_lengths_exception(self):
+        v = Vector([1, 2, 3])
+        with self.assertRaises(ValueError):
+            v + self.v2d
+
+
+    def test_not_implemented_exception(self):
+        with self.assertRaises(TypeError) as exc:
+            self.v2d + 1
+        assert 'unsupported operand' in str(exc.exception)
+       
+
+    def test_reversed_operator(self):
+        v = [10, 20] + self.v2d
+        self.assertEqual(v, Vector([11, 22]))
