Fix stub conversion for Decoratee, so docstrings work, see #117

jedi/inference/gradual/conversion.py

@@ -4,6 +4,7 @@ from jedi.inference.base_value import ValueSet, \
 from jedi.inference.utils import to_list
 from jedi.inference.gradual.stub_value import StubModuleValue
 from jedi.inference.gradual.typeshed import try_to_load_stub_cached
+from jedi.inference.value.decorator import Decoratee
 
 
 def _stub_to_python_value_set(stub_value, ignore_compiled=False):
@@ -11,6 +12,10 @@ def _stub_to_python_value_set(stub_value, ignore_compiled=False):
     if not stub_module_context.is_stub():
         return ValueSet([stub_value])
 
+    decorates = None
+    if isinstance(stub_value, Decoratee):
+        decorates = stub_value._original_value
+
     was_instance = stub_value.is_instance()
     if was_instance:
         stub_value = stub_value.py__class__()
@@ -37,6 +42,8 @@ def _stub_to_python_value_set(stub_value, ignore_compiled=False):
         # Now that the instance has been properly created, we can simply get
         # the method.
         values = values.py__getattribute__(method_name)
+    if decorates is not None:
+        values = ValueSet(Decoratee(v, decorates) for v in values)
     return values
 
 

test/test_api/test_documentation.py

@@ -97,3 +97,21 @@ def test_builtin_docstring(goto_or_help_or_infer, skip_python2):
     doc = d.docstring()
     assert doc.startswith('open(file: Union[')
     assert 'Open file' in doc
+
+
+def test_docstring_decorator(goto_or_help_or_infer, skip_python2):
+    code = dedent('''
+        import types
+
+        def dec(func):
+            return types.FunctionType()
+
+        @dec
+        def func(a, b):
+            "hello"
+            return
+        func''')
+    d, = goto_or_help_or_infer(code)
+
+    doc = d.docstring()
+    assert doc == 'FunctionType(*args: Any, **kwargs: Any) -> Any\n\nhello'