mypy: test_coverage.py, test_data.py

Author: nedbat

tests/coveragetest.py

@@ -18,7 +18,7 @@
 from types import ModuleType
 from typing import (
     Any, Collection, Dict, Generator, Iterable, List, Mapping, Optional,
-    Tuple, Union,
+    Sequence, Tuple, Union,
 )
 
 import coverage
@@ -135,8 +135,8 @@ def _check_arcs(
     def check_coverage(
         self,
         text: str,
-        lines: Optional[Union[List[TLineNo], List[List[TLineNo]]]]=None,
-        missing: Union[str, List[str]]="",
+        lines: Optional[Union[Sequence[TLineNo], Sequence[List[TLineNo]]]]=None,
+        missing: Union[str, Sequence[str]]="",
         report: str="",
         excludes: Optional[Iterable[str]]=None,
         partials: Iterable[str]=(),

tests/helpers.py

@@ -17,7 +17,7 @@
 
 from typing import (
     cast,
-    Any, Callable, Generator, Iterable, List, Optional, Set, Tuple, Type, Union,
+    Any, Callable, Generator, Iterable, List, Optional, Set, Tuple, Type, TypeVar, Union,
 )
 
 import pytest
@@ -281,14 +281,20 @@ def change_dir(new_dir: str) -> Generator[None, None, None]:
     finally:
         os.chdir(old_dir)
 
+T = TypeVar("T")
 
-def assert_count_equal(a: Iterable[Union[int, str]], b: Iterable[Union[int, str]]) -> None:
+def assert_count_equal(
+    a: Optional[Iterable[T]],
+    b: Optional[Iterable[T]],
+) -> None:
     """
     A pytest-friendly implementation of assertCountEqual.
 
     Assert that `a` and `b` have the same elements, but maybe in different order.
     This only works for hashable elements.
     """
+    assert a is not None
+    assert b is not None
     assert collections.Counter(list(a)) == collections.Counter(list(b))