Apply repo-review MyPy suggestions

MY103: MyPy warn unreachable

Must have `warn_unreachable` (true/false) to pass this check. There are
occasionally false positives (often due to platform or Python version
static checks), so it's okay to set it to false if you need to. But try
it first - it can catch real bugs too.

MY104: MyPy enables ignore-without-code

Must have `"ignore-without-code"` in `enable_error_code = [...]`. This
will force all skips in your project to include the error code, which
makes them more readable, and avoids skipping something unintended.

MY105: MyPy enables redundant-expr

Must have `"redundant-expr"` in `enable_error_code = [...]`. This helps
catch useless lines of code, like checking the same condition twice.

MY106: MyPy enables truthy-bool

Must have `"truthy-bool"` in `enable_error_code = []`. This catches
mistakes in using a value as truthy if it cannot be falsy.

pyproject.toml

@@ -119,6 +119,10 @@ title_format = "## [{version}](https://github.com/pypa/pipx/tree/{version}) - {p
 issue_format = "[#{issue}](https://github.com/pypa/pipx/issues/{issue})"
 package = "pipx"
 
+[tool.mypy]
+warn_unreachable = true
+enable_error_code = [ "ignore-without-code", "redundant-expr", "truthy-bool" ]
+
 [[tool.mypy.overrides]]
 module = [
   "pycowsay.*",

src/pipx/animate.py

@@ -101,7 +101,7 @@ def print_animation(
 def win_cursor(visible: bool) -> None:
     if sys.platform != "win32":  # hello mypy
         return
-    ci = _CursorInfo()
+    ci = _CursorInfo()  # type: ignore[unreachable]
     handle = ctypes.windll.kernel32.GetStdHandle(-11)
     ctypes.windll.kernel32.GetConsoleCursorInfo(handle, ctypes.byref(ci))
     ci.visible = visible

src/pipx/commands/environment.py

@@ -38,7 +38,7 @@ def environment(value: str) -> ExitCode:
         "PIPX_HOME_ALLOW_SPACE": str(paths.ctx.allow_spaces_in_home_path).lower(),
     }
     if value is None:
-        print("Environment variables (set by user):")
+        print("Environment variables (set by user):")  # type: ignore[unreachable]
         print("")
         for env_variable in ENVIRONMENT_VARIABLES:
             env_value = os.getenv(env_variable, "")

src/pipx/commands/inject.py

@@ -32,7 +32,7 @@ def inject_dep(
 ) -> bool:
     logger.debug("Injecting package %s", package_spec)
 
-    if not venv_dir.exists() or not next(venv_dir.iterdir()):
+    if not venv_dir.exists() or next(venv_dir.iterdir(), None) is None:
         raise PipxError(
             f"""
             Can't inject {package_spec!r} into nonexistent Virtual Environment

src/pipx/commands/run.py

@@ -198,11 +198,11 @@ def run(
         # we can't parse this as a package
         package_name = app
 
-    content = None if spec is not None else maybe_script_content(app, is_path)
+    content = None if spec is not None else maybe_script_content(app, is_path)  # type: ignore[redundant-expr]
     if content is not None:
         run_script(content, app_args, python, pip_args, venv_args, verbose, use_cache)
     else:
-        package_or_url = spec if spec is not None else app
+        package_or_url = spec if spec is not None else app   # type: ignore[redundant-expr]
         run_package(
             package_name,
             package_or_url,

src/pipx/commands/uninject.py

@@ -125,7 +125,7 @@ def uninject(
 ) -> ExitCode:
     """Returns pipx exit code"""
 
-    if not venv_dir.exists() or not next(venv_dir.iterdir()):
+    if not venv_dir.exists() or next(venv_dir.iterdir(), None) is None:
         raise PipxError(f"Virtual environment {venv_dir.name} does not exist.")
 
     venv = Venv(venv_dir, verbose=verbose)

src/pipx/main.py

@@ -277,7 +277,7 @@ def run_pipx_command(args: argparse.Namespace, subparsers: Dict[str, argparse.Ar
             not args.no_cache,
         )
         # We should never reach here because run() is NoReturn.
-        return ExitCode(1)
+        return ExitCode(1)  # type: ignore[unreachable]
     elif args.command == "install":
         return commands.install(
             None,
@@ -409,7 +409,7 @@ def run_pipx_command(args: argparse.Namespace, subparsers: Dict[str, argparse.Ar
             python_flag_passed=python_flag_passed,
         )
     elif args.command == "runpip":
-        if not venv_dir:
+        if not venv_dir:  # type: ignore[truthy-bool]
             raise PipxError("Developer error: venv_dir is not defined.")
         return commands.run_pip(package, venv_dir, args.pipargs, args.verbose)
     elif args.command == "ensurepath":

src/pipx/paths.py

@@ -107,25 +107,25 @@ def shared_libs(self) -> Path:
         return (self._base_shared_libs or self.home / "shared").resolve()
 
     def make_local(self) -> None:
-        self._base_home = OVERRIDE_PIPX_HOME or get_expanded_environ("PIPX_HOME")
+        self._base_home = OVERRIDE_PIPX_HOME or get_expanded_environ("PIPX_HOME")  # type: ignore[redundant-expr]
         self._default_home = DEFAULT_PIPX_HOME
-        self._base_bin = OVERRIDE_PIPX_BIN_DIR or get_expanded_environ("PIPX_BIN_DIR")
+        self._base_bin = OVERRIDE_PIPX_BIN_DIR or get_expanded_environ("PIPX_BIN_DIR")  # type: ignore[redundant-expr]
         self._default_bin = DEFAULT_PIPX_BIN_DIR
-        self._base_man = OVERRIDE_PIPX_MAN_DIR or get_expanded_environ("PIPX_MAN_DIR")
+        self._base_man = OVERRIDE_PIPX_MAN_DIR or get_expanded_environ("PIPX_MAN_DIR")  # type: ignore[redundant-expr]
         self._default_man = DEFAULT_PIPX_MAN_DIR
-        self._base_shared_libs = OVERRIDE_PIPX_SHARED_LIBS or get_expanded_environ("PIPX_SHARED_LIBS")
+        self._base_shared_libs = OVERRIDE_PIPX_SHARED_LIBS or get_expanded_environ("PIPX_SHARED_LIBS")  # type: ignore[redundant-expr]
         self._default_log = Path(user_log_path("pipx"))
         self._default_cache = Path(user_cache_path("pipx"))
         self._default_trash = self._default_home / "trash"
         self._fallback_home = next(iter([fallback for fallback in FALLBACK_PIPX_HOMES if fallback.exists()]), None)
         self._home_exists = self._base_home is not None or any(fallback.exists() for fallback in FALLBACK_PIPX_HOMES)
 
     def make_global(self) -> None:
-        self._base_home = OVERRIDE_PIPX_GLOBAL_HOME or get_expanded_environ("PIPX_GLOBAL_HOME")
+        self._base_home = OVERRIDE_PIPX_GLOBAL_HOME or get_expanded_environ("PIPX_GLOBAL_HOME")  # type: ignore[redundant-expr]
         self._default_home = DEFAULT_PIPX_GLOBAL_HOME
-        self._base_bin = OVERRIDE_PIPX_GLOBAL_BIN_DIR or get_expanded_environ("PIPX_GLOBAL_BIN_DIR")
+        self._base_bin = OVERRIDE_PIPX_GLOBAL_BIN_DIR or get_expanded_environ("PIPX_GLOBAL_BIN_DIR")  # type: ignore[redundant-expr]
         self._default_bin = DEFAULT_PIPX_GLOBAL_BIN_DIR
-        self._base_man = OVERRIDE_PIPX_GLOBAL_MAN_DIR or get_expanded_environ("PIPX_GLOBAL_MAN_DIR")
+        self._base_man = OVERRIDE_PIPX_GLOBAL_MAN_DIR or get_expanded_environ("PIPX_GLOBAL_MAN_DIR")  # type: ignore[redundant-expr]
         self._default_man = DEFAULT_PIPX_GLOBAL_MAN_DIR
         self._default_log = self._default_home / "logs"
         self._default_cache = self._default_home / ".cache"

src/pipx/shared_libs.py

@@ -114,7 +114,7 @@ def upgrade(self, *, pip_args: List[str], verbose: bool = False, raises: bool =
             return
 
         if pip_args is None:
-            pip_args = []
+            pip_args = []  # type: ignore[unreachable]
 
         logger.info(f"Upgrading shared libraries in {self.root}")
 

tests/test_upgrade_shared.py

@@ -23,7 +23,7 @@ def test_upgrade_shared(shared_libs, capsys, caplog):
     assert "Upgrading shared libraries in" in caplog.text
     assert "Already upgraded libraries in" not in caplog.text
     assert shared_libs.has_been_updated_this_run is True
-    assert shared_libs.is_valid is True
+    assert shared_libs.is_valid is True  # type: ignore[unreachable]
     shared_libs.has_been_updated_this_run = False
     assert run_pipx_cli(["upgrade-shared", "-v"]) == 0
     captured = capsys.readouterr()
@@ -59,7 +59,7 @@ def pip_version():
     assert shared_libs.is_valid is False
     assert run_pipx_cli(["upgrade-shared", "-v", "--pip-args=pip==24.0"]) == 0
     assert shared_libs.is_valid is True
-    assert pip_version() == "24.0"
+    assert pip_version() == "24.0"  # type: ignore[unreachable]
     shared_libs.has_been_updated_this_run = False  # reset for next run
     assert run_pipx_cli(["upgrade-shared", "-v", "--pip-args=pip==23.3.2"]) == 0
     assert shared_libs.is_valid is True