Implement exercise binary-search-tree (#773)

exercises/binary-search-tree/binary_search_tree_test.py

@@ -0,0 +1,58 @@
+import unittest
+
+from binary_search_tree import BinarySearchTree
+
+
+class BinarySearchTreeTests(unittest.TestCase):
+
+    def test_add_integer_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(1)
+        bst.add(8)
+        bst.add(3)
+        bst.add(5)
+        bst.add(2)
+        self.assertEqual(list(bst.list()), [1, 2, 3, 5, 8])
+
+    def test_add_float_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(7.5)
+        bst.add(5.3)
+        bst.add(5.5)
+        bst.add(6.0)
+        bst.add(7.7)
+        self.assertEqual(list(bst.list()), [5.3, 5.5, 6.0, 7.5, 7.7])
+
+    def test_add_mixed_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(1)
+        bst.add(8)
+        bst.add(7.5)
+        bst.add(5.3)
+        self.assertEqual(list(bst.list()), [1, 5.3, 7.5, 8])
+
+    def test_add_duplicated_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(1)
+        bst.add(1)
+        bst.add(7.5)
+        bst.add(5.3)
+        self.assertEqual(list(bst.list()), [1, 1, 5.3, 7.5])
+
+    def test_search_existent_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(1)
+        bst.add(7.5)
+        self.assertEqual(bst.search(1).value, 1)
+        self.assertEqual(bst.search(7.5).value, 7.5)
+
+    def test_search_nonexistent_numbers(self):
+        bst = BinarySearchTree()
+        bst.add(1)
+        bst.add(7.5)
+        self.assertIs(bst.search(6), None)
+        self.assertIs(bst.search(8.8), None)
+
+
+if __name__ == '__main__':
+    unittest.main()