cleanup

hy/lang/string.py

@@ -1,3 +1,3 @@
 class HYString(str):
     def __init__(self, string):
-        self = string
+        self = string  # NOQA

tests/lang/test_expression.py

@@ -7,6 +7,16 @@ code = """
 """
 
 
+def test_basics():
+    """Test the basics"""
+    assert {
+        "function": "fn",
+        "args": [
+            "one"
+        ]
+    } == HYExpression(["fn", "one"]).get_invocation()
+
+
 def test_fn_split():
     """Test if we can get a statement something right."""
     one, two = tokenize(code)