Type annotation tidying

Author: sco1

.gitignore

@@ -41,3 +41,6 @@ coverage.xml
 cov.xml
 htmlcov
 .pytest_cache/
+
+# mypy
+.mypy_cache/

flake8_annotations/__init__.py

@@ -1,6 +1,6 @@
 import sys
 from itertools import zip_longest
-from typing import List, Union
+from typing import List, Set, Union
 
 from flake8_annotations.enums import AnnotationType, ClassDecoratorType, FunctionType
 
@@ -305,8 +305,8 @@ class FunctionVisitor(ast.NodeVisitor):
 
     def __init__(self, lines: List[str]):
         self.lines = lines
-        self.function_definitions = []
-        self._context = []
+        self.function_definitions: List[Function] = []
+        self._context: List[AST_DEF_NODES] = []
 
     def switch_context(self, node: AST_DEF_NODES) -> None:
         """
@@ -354,8 +354,8 @@ class ReturnVisitor(ast.NodeVisitor):
 
     def __init__(self, parent_node: AST_FUNCTION_TYPES):
         self.parent_node = parent_node
-        self._context = []
-        self._non_none_return_nodes = set()
+        self._context: List[AST_FUNCTION_TYPES] = []
+        self._non_none_return_nodes: Set[AST_FUNCTION_TYPES] = set()
 
     @property
     def has_only_none_returns(self) -> bool:

flake8_annotations/checker.py

@@ -1,6 +1,6 @@
 from argparse import Namespace
 from functools import lru_cache
-from typing import Generator, List
+from typing import Generator, List, Tuple
 
 from flake8.options.manager import OptionManager
 from flake8_annotations import (
@@ -20,6 +20,8 @@
 else:
     from typed_ast import ast3 as ast
 
+FORMATTED_ERROR = Tuple[int, int, str, error_codes.Error]
+
 
 class TypeHintChecker:
     """Top level checker for linting the presence of type hints in function definitions."""
@@ -32,8 +34,9 @@ def __init__(self, tree: ast.Module, lines: List[str]):
         # Request `lines` here and join to allow for correct handling of input from stdin
         self.lines = lines
         self.tree = self.get_typed_tree("".join(lines))  # flake8 doesn't strip newlines
+        self.suppress_none_returning: bool  # Set by flake8's config parser
 
-    def run(self) -> Generator[error_codes.Error, None, None]:
+    def run(self) -> Generator[FORMATTED_ERROR, None, None]:
         """
         This method is called by flake8 to perform the actual check(s) on the source code.