Added hash map challenge.

arrays_strings/hash_map/test_hash_map.py

@@ -0,0 +1,45 @@
+from nose.tools import assert_equal
+
+
+class TestHashMap(object):
+    
+    # TODO: It would be better if we had unit tests for each
+    # method in addition to the following end-to-end test
+    def test_end_to_end(self):
+        hash_table = HashTable(10)
+        
+        print("Test: get on an empty hash table index")
+        assert_equal(hash_table.get(0), None)
+        
+        print("Test: set on an empty hash table index")
+        hash_table.set(0, 'foo')
+        assert_equal(hash_table.get(0), 'foo')
+        hash_table.set(1, 'bar')
+        assert_equal(hash_table.get(1), 'bar')
+        
+        print("Test: set on a non empty hash table index")
+        hash_table.set(10, 'foo2')
+        assert_equal(hash_table.get(0), 'foo')
+        assert_equal(hash_table.get(10), 'foo2')
+        
+        print("Test: set on a key that already exists")
+        hash_table.set(10, 'foo3')
+        assert_equal(hash_table.get(0), 'foo')
+        assert_equal(hash_table.get(10), 'foo3')
+        
+        print("Test: remove on a key that already exists")
+        hash_table.remove(10)
+        assert_equal(hash_table.get(0), 'foo')
+        assert_equal(hash_table.get(10), None)
+        
+        print("Test: remove on a key that doesn't exist")
+        hash_table.remove(-1)
+        
+        print('Success: test_end_to_end')
+
+def main():
+    test = TestHashMap()
+    test.test_end_to_end()
+    
+if __name__ == '__main__':
+    main()