Expect docstring hook to provide Type instances rather than tuples of str, int.

Author: chadrik

mypy/fastparse.py

@@ -122,18 +122,10 @@ def parse_docstring(hook: DocstringParserHook, docstring: str, arg_names: List[s
 
     Returns a 2-tuple: (list of arguments Types, and return Type).
     """
-
-    def pop_and_convert(name: str) -> Optional[Type]:
-        t = type_map.pop(name, None)
-        if t is None:
-            return AnyType()
-        else:
-            return parse_type_comment(t[0], t[1], errors)
-
     type_map = hook(docstring, line, errors)
     if type_map:
-        arg_types = [pop_and_convert(name) for name in arg_names]
-        return_type = pop_and_convert('return')
+        arg_types = [type_map.pop(name, AnyType()) for name in arg_names]
+        return_type = type_map.pop('return', AnyType())
         if type_map:
             errors.report(line, 0,
                           TYPE_COMMENT_DOCSTRING_ERROR.format(list(type_map), arg_names))

mypy/plugin.py

@@ -76,10 +76,7 @@
     ],
     Dict[
         str,                     # Argument name, or 'return' for return type.
-        Tuple[
-            str,                 # PEP484-compatible string to use as the argument's type
-            int                  # Line number identifying the location of the type annotation
-        ]
+        Type                     # Corresponding type extracted from docstring
     ]
 ]
 

test-data/unit/plugins/docstring.py

@@ -1,13 +1,14 @@
 from mypy.plugin import Plugin
+from mypy.fastparse import parse_type_comment
 
 class MyPlugin(Plugin):
     def get_docstring_parser_hook(self):
         return my_hook
 
 def my_hook(docstring, line, errs):
     params = [l.split(':', 1) for l in docstring.strip().split('\n')]
-    return {k.strip(): (v.strip(), line + i + 1) for i, (k, v) in enumerate(params)}
+    return {k.strip(): parse_type_comment(v.strip(), line + i + 1, errs)
+            for i, (k, v) in enumerate(params)}
 
 def plugin(version):
     return MyPlugin
-