Enable mypy warn_unused_ignores and remove stale type: ignore comments

The combined "type: ignore[code, ty:rule]" comments made mypy's legacy
parser flag every ty code as unused, which is why warn_unused_ignores was
disabled. With those split into separate mypy and ty pragmas it can be
turned back on.

Verified against Python 3.11-3.15 on linux, darwin, and win32 so that
ignores needed only on some platforms or versions are kept:

- Remove 18 ignores that are unused in every configuration, keeping the
  "ty: ignore" half where ty still needs it.
- Narrow the AnsiDecoder.decode monkey patch ignore to [method-assign].
- Mark the NoConsoleScreenBufferError fallback ignore as
  [no-redef, unused-ignore] since the redefinition only exists on win32.
- Guard Cmd2HelpFormatter._set_color() with a positive version check
  instead of an early return so mypy skips it on Python < 3.14 rather
  than reporting the rest of the method as unreachable.
- Annotate Cmd._initial_termios_settings as list[Any] | None and add an
  explicit platform check to the termios restore code. Previously mypy
  inferred the attribute as always None on win32 and only avoided
  checking that POSIX-only code because it looked unreachable.

Author: tleonhardt

cmd2/annotated.py

@@ -989,7 +989,7 @@ def _unwrap_optional(tp: Any) -> tuple[Any, bool]:
     there alone, so this helper never validates union members itself.
     """
     origin = get_origin(tp)
-    if origin is Union or origin is types.UnionType:  # type: ignore[comparison-overlap]
+    if origin is Union or origin is types.UnionType:
         all_args = get_args(tp)
         non_none = [a for a in all_args if a is not type(None)]
         has_none = len(non_none) < len(all_args)
@@ -1014,14 +1014,14 @@ def _normalize_annotation(annotation: Any) -> _NormalizedAnnotation:
     tp, unwrapped = _unwrap_optional(tp)
     if unwrapped:
         is_optional = True
-        if get_origin(tp) is Annotated:  # type: ignore[comparison-overlap]
+        if get_origin(tp) is Annotated:
             inner_tp = get_args(tp)[0]
             inner_origin = get_origin(inner_tp)
-            inner_is_union = inner_origin is Union or inner_origin is types.UnionType  # type: ignore[comparison-overlap]
+            inner_is_union = inner_origin is Union or inner_origin is types.UnionType
             if not (inner_is_union and type(None) in get_args(inner_tp)):
                 raise TypeError("Annotated[T, meta] | None is ambiguous. Use Annotated[T | None, meta] instead.")
 
-    if get_origin(tp) is Annotated:  # type: ignore[comparison-overlap]
+    if get_origin(tp) is Annotated:
         args = get_args(tp)
         tp = args[0]
         for meta in args[1:]:

cmd2/cmd2.py

@@ -183,13 +183,13 @@
 
 try:
     if sys.platform == "win32":
-        from prompt_toolkit.output.win32 import NoConsoleScreenBufferError  # type: ignore[attr-defined]
+        from prompt_toolkit.output.win32 import NoConsoleScreenBufferError
     else:
         # Trigger the except block for non-Windows platforms
         raise ImportError  # noqa: TRY301
 except ImportError:
 
-    class NoConsoleScreenBufferError(Exception):  # type: ignore[no-redef]
+    class NoConsoleScreenBufferError(Exception):  # type: ignore[no-redef, unused-ignore]
         """Dummy exception to use when prompt_toolkit.output.win32.NoConsoleScreenBufferError is not available."""
 
         def __init__(self, msg: str = "") -> None:
@@ -617,7 +617,7 @@ def __init__(
 
         # Store initial termios settings to restore after each command.
         # This is a faster way of accomplishing what "stty sane" does.
-        self._initial_termios_settings = None
+        self._initial_termios_settings: list[Any] | None = None
         if not sys.platform.startswith("win") and self.stdin.isatty():
             try:
                 import io
@@ -1042,7 +1042,7 @@ def _build_parser(
 
         # Verify the factory returned the required type
         if not isinstance(parser, Cmd2ArgumentParser):
-            builder_name = getattr(parser_source, "__name__", str(parser_source))  # type: ignore[unreachable]
+            builder_name = getattr(parser_source, "__name__", str(parser_source))
             raise TypeError(
                 f"'{builder_name}' must return a 'Cmd2ArgumentParser' (or subclass). Received: '{type(parser).__name__}'."
             )
@@ -1982,8 +1982,8 @@ def ppaged(
 
                 # If the pager was killed (e.g. SIGKILL), the terminal might be in a bad state.
                 # Attempt to restore terminal settings and foreground process group.
-                if self._initial_termios_settings is not None and self.stdin.isatty():  # type: ignore[unreachable]
-                    try:  # type: ignore[unreachable]
+                if not sys.platform.startswith("win") and self._initial_termios_settings is not None and self.stdin.isatty():
+                    try:
                         import signal
                         import termios
 
@@ -3109,8 +3109,8 @@ def onecmd_plus_hooks(
 
     def _run_cmdfinalization_hooks(self, stop: bool, statement: Statement | None) -> bool:
         """Run the command finalization hooks."""
-        if self._initial_termios_settings is not None and self.stdin.isatty():  # type: ignore[unreachable]
-            import io  # type: ignore[unreachable]
+        if not sys.platform.startswith("win") and self._initial_termios_settings is not None and self.stdin.isatty():
+            import io
             import termios
 
             # Before the next command runs, fix any terminal problems like those
@@ -3875,7 +3875,7 @@ def _build_alias_parser() -> Cmd2ArgumentParser:
             "An alias is a command that enables replacement of a word by another string.",
         )
         alias_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=alias_description)
-        alias_parser.epilog = TextGroup(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        alias_parser.epilog = TextGroup(  # ty: ignore[invalid-assignment]
             "See Also",
             "macro",
         )
@@ -3907,7 +3907,7 @@ def _build_alias_create_parser(cls) -> Cmd2ArgumentParser:
                 "for the actual command the alias resolves to."
             ),
         )
-        alias_create_parser.epilog = TextGroup("Notes", alias_create_notes)  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        alias_create_parser.epilog = TextGroup("Notes", alias_create_notes)  # ty: ignore[invalid-assignment]
 
         # Add arguments
         alias_create_parser.add_argument("name", help="name of this alias")
@@ -4089,7 +4089,7 @@ def _build_macro_parser() -> Cmd2ArgumentParser:
             "A macro is similar to an alias, but it can contain argument placeholders.",
         )
         macro_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=macro_description)
-        macro_parser.epilog = TextGroup(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        macro_parser.epilog = TextGroup(  # ty: ignore[invalid-assignment]
             "See Also",
             "alias",
         )
@@ -4152,7 +4152,7 @@ def _build_macro_create_parser(cls) -> Cmd2ArgumentParser:
                 "This default behavior changes if custom completion for macro arguments has been implemented."
             ),
         )
-        macro_create_parser.epilog = TextGroup("Notes", macro_create_notes)  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        macro_create_parser.epilog = TextGroup("Notes", macro_create_notes)  # ty: ignore[invalid-assignment]
 
         # Add arguments
         macro_create_parser.add_argument("name", help="name of this macro")
@@ -4648,7 +4648,7 @@ def do_shortcuts(self, _: argparse.Namespace) -> None:
     @staticmethod
     def _build__eof_parser() -> Cmd2ArgumentParser:
         _eof_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Called when Ctrl-D is pressed.")
-        _eof_parser.epilog = TextGroup(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        _eof_parser.epilog = TextGroup(  # ty: ignore[invalid-assignment]
             "Note",
             "This command is for internal use and is not intended to be called from the command line.",
         )
@@ -4982,7 +4982,7 @@ def _set_up_py_shell_env(self, interp: InteractiveConsole) -> _SavedCmd2Env:
             cmd2_env.completer = readline.get_completer()
 
             # Set the completer to use the interpreter's locals
-            readline.set_completer(rlcompleter.Completer(interp.locals).complete)  # type: ignore[arg-type]
+            readline.set_completer(rlcompleter.Completer(interp.locals).complete)
 
             # Use the correct binding based on whether LibEdit or Readline is being used
             if "libedit" in (readline.__doc__ or ""):
@@ -5259,7 +5259,7 @@ def do_ipy(self, _: argparse.Namespace) -> bool | None:  # pragma: no cover
             )
 
             # Start IPython
-            start_ipython(config=config, argv=[], user_ns=local_vars)  # type: ignore[no-untyped-call]
+            start_ipython(config=config, argv=[], user_ns=local_vars)
             self.poutput("Now exiting IPython shell...")
 
             # The IPython application is a singleton and won't be recreated next time
@@ -5547,7 +5547,7 @@ def _persist_history(self) -> None:
     def _build_edit_parser(cls) -> Cmd2ArgumentParser:
         edit_description = "Run a text editor and optionally open a file with it."
         edit_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=edit_description)
-        edit_parser.epilog = TextGroup(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        edit_parser.epilog = TextGroup(  # ty: ignore[invalid-assignment]
             "Note",
             Text.assemble(
                 "To set a new editor, run: ",
@@ -5669,7 +5669,7 @@ def _build__relative_run_script_parser(cls) -> Cmd2ArgumentParser:
         _relative_run_script_parser = cls._build_base_run_script_parser()
 
         # Append to existing description
-        _relative_run_script_parser.description = Group(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        _relative_run_script_parser.description = Group(  # ty: ignore[invalid-assignment]
             cast(Group, _relative_run_script_parser.description),
             "\n",
             (
@@ -5678,7 +5678,7 @@ def _build__relative_run_script_parser(cls) -> Cmd2ArgumentParser:
             ),
         )
 
-        _relative_run_script_parser.epilog = TextGroup(  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        _relative_run_script_parser.epilog = TextGroup(  # ty: ignore[invalid-assignment]
             "Note",
             "This command is intended to be used from within a text script.",
         )

cmd2/decorators.py

@@ -311,7 +311,7 @@ def arg_decorator(func: ArgparseCommandFunc[CmdOrSetT]) -> RawCommandFunc[CmdOrS
         :return: Function that takes raw input and converts to an argparse Namespace to passed to the wrapped function.
         """
 
-        @functools.wraps(func)  # type: ignore[arg-type]  # ty: ignore[invalid-argument-type]
+        @functools.wraps(func)  # ty: ignore[invalid-argument-type]
         def cmd_wrapper(*args: Any, **kwargs: Any) -> bool | None:
             """Command function wrapper which translates command line into argparse Namespace and call actual command function.
 
@@ -346,9 +346,9 @@ def cmd_wrapper(*args: Any, **kwargs: Any) -> bool | None:
                 parsing_results: tuple[argparse.Namespace] | tuple[argparse.Namespace, list[str]]
                 with arg_parser.output_to(cmd_app.stdout):
                     if with_unknown_args:
-                        parsing_results = arg_parser.parse_known_args(command_arg_list, initial_namespace)  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+                        parsing_results = arg_parser.parse_known_args(command_arg_list, initial_namespace)  # ty: ignore[invalid-assignment]
                     else:
-                        parsing_results = (arg_parser.parse_args(command_arg_list, initial_namespace),)  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+                        parsing_results = (arg_parser.parse_args(command_arg_list, initial_namespace),)  # ty: ignore[invalid-assignment]
             except SystemExit as exc:
                 raise Cmd2ArgparseError from exc
 

cmd2/rich_utils.py

@@ -174,14 +174,12 @@ def _set_color(self, color: bool, **kwargs: Any) -> None:
         to _set_color() which some versions of RichHelpFormatter don't support.
         """
         # Argparse didn't add color support until 3.14
-        if sys.version_info < (3, 14):
-            return
-
-        try:  # type: ignore[unreachable]
-            super()._set_color(color, **kwargs)
-        except TypeError:
-            # Fallback for older versions of RichHelpFormatter that don't support keyword arguments
-            super()._set_color(color)
+        if sys.version_info >= (3, 14):
+            try:
+                super()._set_color(color, **kwargs)
+            except TypeError:
+                # Fallback for older versions of RichHelpFormatter that don't support keyword arguments
+                super()._set_color(color)
 
     def _build_nargs_range_str(self, nargs_range: tuple[int, int | float]) -> str:
         """Build nargs range string for help text."""
@@ -710,4 +708,4 @@ def _decode_has_linebreak_bug() -> bool:
 
 # Only apply the monkey patch if the bug is present
 if _decode_has_linebreak_bug():
-    AnsiDecoder.decode = _AnsiDecoder_decode  # type: ignore[assignment]
+    AnsiDecoder.decode = _AnsiDecoder_decode  # type: ignore[method-assign]

pyproject.toml

@@ -98,7 +98,7 @@ strict = true
 warn_redundant_casts = true
 warn_return_any = true
 warn_unreachable = true
-warn_unused_ignores = false
+warn_unused_ignores = true
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]