👷 Add ty to the CI lint check

pyproject.toml

@@ -81,6 +81,7 @@ github-actions = [
 tests = [
     "coverage[toml]>=6.2,<8.0",
     "mypy==1.19.1",
+    "ty==0.0.9",
     "pytest>=4.4.0,<9.0.0",
     "pytest-cov>=2.10.0,<8.0.0",
     "pytest-sugar>=0.9.4,<1.2.0",

scripts/lint.sh

@@ -4,5 +4,6 @@ set -e
 set -x
 
 mypy typer
+ty check typer
 ruff check typer tests docs_src scripts
 ruff format typer tests docs_src scripts --check

typer/_completion_classes.py

@@ -2,7 +2,7 @@
 import os
 import re
 import sys
-from typing import Any
+from typing import Any, Callable, cast
 
 import click
 import click.parser
@@ -17,13 +17,16 @@
 )
 
 try:
-    from click.shell_completion import split_arg_string as click_split_arg_string
+    from click.shell_completion import split_arg_string as _split_arg_string
 except ImportError:  # pragma: no cover
-    # TODO: when removing support for Click < 8.2, remove this import
+    # TODO: when removing support for Click < 8.2, remove this import & the cast
     from click.parser import (  # type: ignore[no-redef]
-        split_arg_string as click_split_arg_string,
+        split_arg_string as _split_arg_string,
     )
 
+# We need this cast to make ty happy
+click_split_arg_string = cast(Callable[[str], list[str]], _split_arg_string)
+
 
 def _sanitize_help_text(text: str) -> str:
     """Sanitizes the help text by removing rich tags"""

typer/cli.py

@@ -57,9 +57,9 @@ def list_commands(self, ctx: click.Context) -> list[str]:
         self.maybe_add_run(ctx)
         return super().list_commands(ctx)
 
-    def get_command(self, ctx: click.Context, name: str) -> Optional[Command]:
+    def get_command(self, ctx: click.Context, cmd_name: str) -> Optional[Command]:
         self.maybe_add_run(ctx)
-        return super().get_command(ctx, name)
+        return super().get_command(ctx, cmd_name)
 
     def invoke(self, ctx: click.Context) -> Any:
         self.maybe_add_run(ctx)
@@ -131,6 +131,7 @@ def get_typer_from_state() -> Optional[typer.Typer]:
         else:
             typer.echo(f"Could not import as Python module: {state.module}", err=True)
         sys.exit(1)
+    assert spec is not None
     module = importlib.util.module_from_spec(spec)
     spec.loader.exec_module(module)  # type: ignore
     obj = get_typer_from_module(module)

typer/main.py

@@ -72,6 +72,7 @@ def except_hook(
         _original_except_hook(exc_type, exc_value, tb)
         return
     typer_path = os.path.dirname(__file__)
+    assert click.__file__ is not None
     click_path = os.path.dirname(click.__file__)
     internal_dir_names = [typer_path, click_path]
     exc = exc_value