Generate annotations for NewType types (fixes #22) (#23)

.gitignore

@@ -8,3 +8,4 @@ htmlcov/
 doc/_build
 dist/
 build/
+.idea/

CHANGES.rst

@@ -5,7 +5,7 @@ master
 ------
 
 * Fix passing args to script run with ``monkeytype run`` (#18; merge of #21).
-
+* Fix generated annotations for NewType types (#22; merge of #23).
 
 17.12.1
 -------

monkeytype/stubs.py

@@ -319,6 +319,8 @@ def render_annotation(anno: Any) -> str:
         elem_type = _get_optional_elem(anno)
         rendered = render_annotation(elem_type)
         return 'Optional[' + rendered + ']'
+    elif hasattr(anno, '__supertype__'):
+        return anno.__name__
     elif getattr(anno, '__module__', None) == 'typing':
         return repr(anno).replace('typing.', '')
     elif anno is NoneType:

tests/test_stubs.py

@@ -11,6 +11,7 @@
     Generator,
     Iterator,
     List,
+    NewType,
     Optional,
     Set,
     Tuple,
@@ -42,6 +43,8 @@
 from monkeytype.typing import NoneType
 from .util import Dummy
 
+UserId = NewType('UserId', int)
+
 
 class TestImportMap:
     def test_merge(self):
@@ -133,6 +136,10 @@ def has_length_exceeds_120_chars(
     return None
 
 
+def has_newtype_param(user_id: UserId) -> None:
+    pass
+
+
 class TestHasUnparsableDefaults:
     @pytest.mark.parametrize(
         'func, expected',
@@ -241,6 +248,11 @@ def test_default_none_parameter_annotation(self):
         expected = 'def test(x: Optional[int] = None) -> None: ...'
         assert stub.render() == expected
 
+    def test_newtype_parameter_annotation(self):
+        stub = FunctionStub('test', inspect.signature(has_newtype_param), FunctionKind.MODULE)
+        expected = 'def test(user_id: UserId) -> None: ...'
+        assert stub.render() == expected
+
 
 def _func_stub_from_callable(func: Callable, strip_modules: List[str] = None):
     kind = FunctionKind.from_callable(func)