mypy: Make the config stricter

Author: Tavian Barnes

python/bistring/_alignment.py

@@ -103,7 +103,7 @@ def __init__(self, values: Iterable[Bounds]):
 
     @classmethod
     def _create(cls, original: List[int], modified: List[int]) -> Alignment:
-        result = super().__new__(cls)
+        result: Alignment = super().__new__(cls)
         result._original = original
         result._modified = modified
         return result
@@ -146,7 +146,7 @@ def _parse_bounds(cls, args: Tuple[AnyBounds, ...]) -> Bounds:
                     raise ValueError('slice with unspecified bounds')
                 return arg.start, arg.stop
             elif isinstance(arg, tuple):
-                return cast(Bounds, arg)
+                return arg
             else:
                 return 0, arg
         elif l == 2:

python/bistring/_bistr.py

@@ -96,7 +96,7 @@ def __new__(cls, original: String, modified: Optional[str] = None, alignment: Op
         elif alignment.modified_bounds() != (0, len(modified)):
             raise ValueError('Alignment incompatible with modified string')
 
-        result = object.__new__(cls)
+        result: bistr = object.__new__(cls)
         object.__setattr__(result, 'original', original)
         object.__setattr__(result, 'modified', modified)
         object.__setattr__(result, 'alignment', alignment)

python/bistring/_token.py

@@ -18,7 +18,7 @@
 from dataclasses import dataclass
 import icu
 import threading
-from typing import Callable, Iterable, Iterator, Sequence, Union, overload
+from typing import Callable, Iterable, Iterator, Optional, Sequence, Union, overload
 
 from ._alignment import Alignment
 from ._bistr import bistr, String
@@ -360,9 +360,11 @@ def __init__(self, locale: str, constructor: Callable[[icu.Locale], icu.BreakIte
         self._break_iterator()
 
     def _break_iterator(self) -> icu.BreakIterator:
-        if not hasattr(self._local, 'bi'):
-            self._local.bi = self._constructor(self._locale)
-        return self._local.bi
+        bi: Optional[icu.BreakIterator] = getattr(self._local, 'bi', None)
+        if bi is None:
+            bi = self._constructor(self._locale)
+            self._local.bi = bi
+        return bi
 
     def tokenize(self, text: String) -> Tokenization:
         text = bistr(text)

python/mypy.ini

@@ -1,2 +1,14 @@
 [mypy]
 mypy_path = ./stubs
+disallow_subclassing_any = True
+disallow_untyped_calls = True
+disallow_untyped_defs = True
+disallow_incomplete_defs = True
+disallow_untyped_decorators = True
+no_implicit_optional = True
+warn_no_return = True
+warn_return_any = True
+warn_unreachable = True
+warn_incomplete_stub = True
+warn_redundant_casts = True
+show_error_context = True

python/stubs/icu.pyi

@@ -40,7 +40,7 @@ class CaseMap:
 
 
 class Edits:
-    def __init__(self): ...
+    def __init__(self) -> None: ...
 
     def getFineIterator(self) -> Iterator[Tuple[bool, int, int, int, int, int]]: ...