mypy: Turn on return value checks

Its a shame GvR is married to "return None"
https://github.com/python/mypy/issues/7511

kittens/broadcast/main.py

@@ -106,6 +106,7 @@ def main(args: List[str]) -> Optional[Dict[str, Any]]:
     loop = Loop()
     handler = Broadcast(opts, items)
     loop.loop(handler)
+    return None
 
 
 if __name__ == '__main__':

kittens/diff/patch.py

@@ -24,6 +24,7 @@ def find_differ() -> Optional[str]:
         return GIT_DIFF
     if shutil.which('diff'):
         return DIFF_DIFF
+    return None
 
 
 def set_diff_command(opt: str) -> None:

kittens/hints/main.py

@@ -688,6 +688,7 @@ def main(args: List[str]) -> Optional[Dict[str, Any]]:
         import traceback
         traceback.print_exc()
         input(_('Press Enter to quit'))
+    return None
 
 
 def linenum_handle_result(args: List[str], data: Dict[str, Any], target_window_id: int, boss: BossType, extra_cli_args: Sequence[str], *a: Any) -> None:

kittens/remote_file/main.py

@@ -132,7 +132,7 @@ class ControlMaster:
             self.dest = os.path.join(self.tdir, os.path.basename(self.remote_path))
         return self
 
-    def __exit__(self, *a: Any) -> bool:
+    def __exit__(self, *a: Any) -> None:
         subprocess.Popen(
             self.batch_cmd_prefix + ['-O', 'exit', self.conn_data.hostname],
             stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, stdin=subprocess.DEVNULL
@@ -215,6 +215,7 @@ def main(args: List[str]) -> Result:
         import traceback
         traceback.print_exc()
         show_error('Failed with unhandled exception')
+    return None
 
 
 def save_as(conn_data: SSHConnectionData, remote_path: str, cli_opts: RemoteFileCLIOptions) -> None:
@@ -312,6 +313,7 @@ def handle_action(action: str, cli_opts: RemoteFileCLIOptions) -> Result:
     elif action == 'save':
         print('Saving', cli_opts.path, 'from', cli_opts.hostname)
         save_as(conn_data, remote_path, cli_opts)
+    return None
 
 
 @result_handler()

kittens/themes/main.py

@@ -203,6 +203,7 @@ class ThemesHandler(Handler):
             col = color_as_sharp(color_from_int(o.color_table[i]))
             cmds.append(f'{i};{col}')
         self.print(end='\033]4;' + ';'.join(cmds) + '\033\\')
+        return True
 
     def redraw_after_category_change(self) -> None:
         self.themes_list.update_themes(self.all_themes.filtered(self.filter_map[self.current_category]))

kittens/transfer/send.py

@@ -312,6 +312,7 @@ class SendManager:
             ans = self.files[self.active_idx]
             if ans.state is FileState.transmitting:
                 return ans
+        return None
 
     def activate_next_ready_file(self) -> Optional[File]:
         if self.active_idx is not None:
@@ -325,6 +326,7 @@ class SendManager:
                 return f
         self.active_idx = None
         self.update_collective_statuses()
+        return None
 
     def update_collective_statuses(self) -> None:
         found_not_started = found_not_done = False

kittens/tui/handler.py

@@ -83,6 +83,7 @@ class Handler:
         for sc, action in self._key_shortcuts.items():
             if key_event.matches(sc):
                 return action
+        return None
 
     def __enter__(self) -> None:
         if self._image_manager is not None:

kittens/tui/path_completer.py

@@ -132,6 +132,7 @@ class PathCompleter:
             options = self.cache[text] = tuple(find_completions(text))
         if options and state < len(options):
             return options[state]
+        return None
 
     def __exit__(self, *a: Any) -> bool:
         import readline
@@ -143,6 +144,7 @@ class PathCompleter:
     def input(self) -> str:
         with self:
             return input(self.prompt)
+        return ''
 
 
 def develop() -> None:

kittens/unicode_input/main.py

@@ -157,6 +157,7 @@ class Table:
     def current_codepoint(self) -> Optional[int]:
         if self.codepoints:
             return self.codepoints[self.current_idx]
+        return None
 
     def set_codepoints(self, codepoints: List[int], mode: str = HEX, current_idx: int = 0) -> None:
         self.codepoints = codepoints

kitty/boss.py

@@ -9,8 +9,8 @@ from contextlib import suppress
 from functools import partial
 from gettext import gettext as _
 from typing import (
-    Any, Callable, Dict, Generator, Iterable, List, Optional, Tuple, Union,
+    Any, Callable, Dict, Iterable, Iterator, List, Optional, Tuple,
-    cast
+    Union, cast
 )
 from weakref import WeakValueDictionary
 
@@ -27,16 +27,16 @@ from .constants import (
 )
 from .fast_data_types import (
     CLOSE_BEING_CONFIRMED, GLFW_MOD_ALT, GLFW_MOD_CONTROL, GLFW_MOD_SHIFT,
-    GLFW_MOD_SUPER, IMPERATIVE_CLOSE_REQUESTED, NO_CLOSE_REQUESTED,
+    GLFW_MOD_SUPER, GLFW_MOUSE_BUTTON_LEFT, GLFW_PRESS,
-    ChildMonitor, KeyEvent, add_timer, apply_options_update,
+    IMPERATIVE_CLOSE_REQUESTED, NO_CLOSE_REQUESTED, ChildMonitor, KeyEvent,
-    background_opacity_of, change_background_opacity, change_os_window_state,
+    add_timer, apply_options_update, background_opacity_of,
-    cocoa_set_menubar_title, create_os_window, GLFW_PRESS, GLFW_MOUSE_BUTTON_LEFT,
+    change_background_opacity, change_os_window_state, cocoa_set_menubar_title,
-    current_application_quit_request, current_os_window, destroy_global_data,
+    create_os_window, current_application_quit_request, current_os_window,
-    focus_os_window, get_clipboard_string, get_options, get_os_window_size,
+    destroy_global_data, focus_os_window, get_clipboard_string, get_options,
-    global_font_size, mark_os_window_for_close, os_window_font_size,
+    get_os_window_size, global_font_size, mark_os_window_for_close,
-    patch_global_colors, redirect_mouse_handling, ring_bell, safe_pipe,
+    os_window_font_size, patch_global_colors, redirect_mouse_handling,
-    set_application_quit_request, set_background_image, set_boss,
+    ring_bell, safe_pipe, set_application_quit_request, set_background_image,
-    set_clipboard_string, set_in_sequence_mode, set_options,
+    set_boss, set_clipboard_string, set_in_sequence_mode, set_options,
     set_os_window_size, thread_write, toggle_fullscreen, toggle_maximized
 )
 from .key_encoding import get_name_to_functional_number_map
@@ -234,7 +234,7 @@ class Boss:
         self.os_window_map[os_window_id] = tm
         return os_window_id
 
-    def list_os_windows(self, self_window: Optional[Window] = None) -> Generator[OSWindowDict, None, None]:
+    def list_os_windows(self, self_window: Optional[Window] = None) -> Iterator[OSWindowDict]:
         with cached_process_data():
             active_tab, active_window = self.active_tab, self.active_window
             active_tab_manager = self.active_tab_manager
@@ -249,20 +249,20 @@ class Boss:
                 }
 
     @property
-    def all_tab_managers(self) -> Generator[TabManager, None, None]:
+    def all_tab_managers(self) -> Iterator[TabManager]:
         yield from self.os_window_map.values()
 
     @property
-    def all_tabs(self) -> Generator[Tab, None, None]:
+    def all_tabs(self) -> Iterator[Tab]:
         for tm in self.all_tab_managers:
             yield from tm
 
     @property
-    def all_windows(self) -> Generator[Window, None, None]:
+    def all_windows(self) -> Iterator[Window]:
         for tab in self.all_tabs:
             yield from tab
 
-    def match_windows(self, match: str) -> Generator[Window, None, None]:
+    def match_windows(self, match: str) -> Iterator[Window]:
         try:
             field, exp = match.split(':', 1)
         except ValueError:
@@ -305,8 +305,9 @@ class Boss:
             for w in tab:
                 if w.id == window.id:
                     return tab
+        return None
 
-    def match_tabs(self, match: str) -> Generator[Tab, None, None]:
+    def match_tabs(self, match: str) -> Iterator[Tab]:
         try:
             field, exp = match.split(':', 1)
         except ValueError:
@@ -359,6 +360,7 @@ class Boss:
                         if switch_os_window_if_needed and current_os_window() != os_window_id:
                             focus_os_window(os_window_id, True)
                         return os_window_id
+        return None
 
     def _new_os_window(self, args: Union[SpecialWindowInstance, Iterable[str]], cwd_from: Optional[int] = None) -> int:
         if isinstance(args, SpecialWindowInstance):
@@ -377,6 +379,7 @@ class Boss:
         t = self.active_tab
         if t is not None:
             return t.active_window_for_cwd
+        return None
 
     @ac('win', 'New OS Window with the same working directory as the currently active window')
     def new_os_window_with_cwd(self, *args: str) -> None:
@@ -595,7 +598,7 @@ class Boss:
             run_update_check(get_options().update_check_interval * 60 * 60)
             self.update_check_started = True
 
-    def handle_click_on_tab(self, os_window_id: int, x: int, button: int, modifiers: int, action: int) -> int:
+    def handle_click_on_tab(self, os_window_id: int, x: int, button: int, modifiers: int, action: int) -> None:
         tm = self.os_window_map.get(os_window_id)
         if tm is not None:
             tm.handle_click_on_tab(x, button, modifiers, action)
@@ -751,20 +754,17 @@ class Boss:
     @property
     def active_tab_manager(self) -> Optional[TabManager]:
         os_window_id = current_os_window()
-        if os_window_id is not None:
+        return None if os_window_id is None else self.os_window_map.get(os_window_id)
-            return self.os_window_map.get(os_window_id)
 
     @property
     def active_tab(self) -> Optional[Tab]:
         tm = self.active_tab_manager
-        if tm is not None:
+        return None if tm is None else tm.active_tab
-            return tm.active_tab
 
     @property
     def active_window(self) -> Optional[Window]:
         t = self.active_tab
-        if t is not None:
+        return None if t is None else t.active_window
-            return t.active_window
 
     def set_pending_sequences(self, sequences: SubSequenceMap, default_pending_action: Optional[KeyAction] = None) -> None:
         self.pending_sequences = sequences
@@ -783,6 +783,7 @@ class Boss:
                 return True
         elif isinstance(key_action, KeyAction):
             return self.dispatch_action(key_action)
+        return False
 
     def clear_pending_sequences(self) -> None:
         self.pending_sequences = self.default_pending_action = None
@@ -1530,7 +1531,7 @@ class Boss:
         else:
             subprocess.Popen(cmd, env=env, cwd=cwd)
 
-    def pipe(self, source: str, dest: str, exe: str, *args: str) -> Window:
+    def pipe(self, source: str, dest: str, exe: str, *args: str) -> Optional[Window]:
         cmd = [exe] + list(args)
         window = self.active_window
         cwd_from = window.child.pid_for_cwd if window else None
@@ -1559,6 +1560,7 @@ class Boss:
         else:
             env, stdin = self.process_stdin_source(stdin=source, window=window)
             self.run_background_process(cmd, cwd_from=cwd_from, stdin=stdin, env=env)
+        return None
 
     def args_to_special_window(self, args: Iterable[str], cwd_from: Optional[int] = None) -> SpecialWindowInstance:
         args = list(args)
@@ -1591,6 +1593,7 @@ class Boss:
         tm = self.active_tab_manager
         if tm is not None:
             return tm.new_tab(special_window=special_window, cwd_from=cwd_from, as_neighbor=as_neighbor)
+        return None
 
     def _create_tab(self, args: List[str], cwd_from: Optional[int] = None) -> None:
         as_neighbor = False
@@ -1615,21 +1618,22 @@ class Boss:
 
     def _new_window(self, args: List[str], cwd_from: Optional[int] = None) -> Optional[Window]:
         tab = self.active_tab
-        if tab is not None:
+        if tab is None:
-            allow_remote_control = False
+            return None
-            location = None
+        allow_remote_control = False
-            if args and args[0].startswith('!'):
+        location = None
-                location = args[0][1:].lower()
+        if args and args[0].startswith('!'):
-                args = args[1:]
+            location = args[0][1:].lower()
-            if args and args[0] == '@':
+            args = args[1:]
-                args = args[1:]
+        if args and args[0] == '@':
-                allow_remote_control = True
+            args = args[1:]
-            if args:
+            allow_remote_control = True
-                return tab.new_special_window(
+        if args:
-                    self.args_to_special_window(args, cwd_from=cwd_from),
+            return tab.new_special_window(
-                    location=location, allow_remote_control=allow_remote_control)
+                self.args_to_special_window(args, cwd_from=cwd_from),
-            else:
+                location=location, allow_remote_control=allow_remote_control)
-                return tab.new_window(cwd_from=cwd_from, location=location, allow_remote_control=allow_remote_control)
+        else:
+            return tab.new_window(cwd_from=cwd_from, location=location, allow_remote_control=allow_remote_control)
 
     @ac('win', 'Create a new window')
     def new_window(self, *args: str) -> None:

kitty/child.py

@@ -333,6 +333,7 @@ class Child:
         with suppress(Exception):
             assert self.pid is not None
             return cwd_of_process(self.pid)
+        return None
 
     @property
     def pid_for_cwd(self) -> Optional[int]:
@@ -349,6 +350,7 @@ class Child:
         with suppress(Exception):
             assert self.pid_for_cwd is not None
             return cwd_of_process(self.pid_for_cwd) or None
+        return None
 
     @property
     def foreground_environ(self) -> Dict[str, str]:

kitty/file_transmission.py

@@ -951,3 +951,4 @@ class TestFileTransmission(FileTransmission):
 
     def callback_after(self, callback: Callable[[Optional[int]], None], timeout: float = 0) -> Optional[int]:
         callback(None)
+        return None

kitty/fonts/box_drawing.py

@@ -10,7 +10,7 @@ import math
 from functools import partial as p, wraps
 from itertools import repeat
 from typing import (
-    Any, Callable, Dict, Generator, Iterable, List, MutableSequence, Optional,
+    Any, Callable, Dict, Iterable, Iterator, List, MutableSequence, Optional,
     Sequence, Tuple, cast
 )
 
@@ -314,6 +314,7 @@ def mid_lines(buf: SSByteArray, width: int, height: int, level: int = 1, pts: It
             return width - 1, mid_y
         if p == 'b':
             return mid_x, height - 1
+        raise KeyError(f'Unknown p: {p}')
 
     for x in pts:
         p1, p2 = map(pt_to_coords, x)
@@ -353,7 +354,7 @@ def find_bezier_for_D(width: int, height: int) -> int:
         cx += 1
 
 
-def get_bezier_limits(bezier_x: ParameterizedFunc, bezier_y: ParameterizedFunc) -> Generator[Tuple[float, float], None, int]:
+def get_bezier_limits(bezier_x: ParameterizedFunc, bezier_y: ParameterizedFunc) -> Iterator[Tuple[float, float]]:
     start_x = int(bezier_x(0))
     max_x = int(bezier_x(0.5))
     last_t, t_limit = 0., 0.5
@@ -1043,8 +1044,9 @@ def render_missing_glyph(buf: BufType, width: int, height: int) -> None:
 
 def test_char(ch: str, sz: int = 48) -> None:
     # kitty +runpy "from kitty.fonts.box_drawing import test_char; test_char('XXX')"
-    from .render import display_bitmap, setup_for_testing
     from kitty.fast_data_types import concat_cells, set_send_sprite_to_gpu
+
+    from .render import display_bitmap, setup_for_testing
     with setup_for_testing('monospace', sz) as (_, width, height):
         buf = bytearray(width * height)
         try:
@@ -1062,9 +1064,10 @@ def test_char(ch: str, sz: int = 48) -> None:
 
 
 def test_drawing(sz: int = 48, family: str = 'monospace', start: int = 0x2500, num_rows: int = 10, num_cols: int = 16) -> None:
-    from .render import display_bitmap, setup_for_testing
     from kitty.fast_data_types import concat_cells, set_send_sprite_to_gpu
 
+    from .render import display_bitmap, setup_for_testing
+
     with setup_for_testing(family, sz) as (_, width, height):
         space = bytearray(width * height)
 

kitty/layout/base.py

@@ -69,6 +69,7 @@ def idx_for_id(win_id: int, windows: Iterable[WindowType]) -> Optional[int]:
     for i, w in enumerate(windows):
         if w.id == win_id:
             return i
+    return None
 
 
 def set_layout_options(opts: Options) -> None:

kitty/layout/grid.py

@@ -81,6 +81,7 @@ class Grid(Layout):
                 if idx == window_idx:
                     return row_num, col_num
                 row_num += 1
+            return 0, 0
 
         row_num, col_num = position_for_window_idx(idx)
 

kitty/layout/splits.py

@@ -86,6 +86,7 @@ class Pair:
         for q in root.self_and_descendants():
             if q.one is self or q.two is self:
                 return q
+        return None
 
     def remove_windows(self, window_ids: Collection[int]) -> None:
         if isinstance(self.one, int) and self.one in window_ids:
@@ -548,6 +549,7 @@ class Splits(Layout):
                     if swap:
                         pair.one, pair.two = pair.two, pair.one
                     return True
+        return None
 
     def layout_state(self) -> Dict[str, Any]:
 

kitty/layout/tall.py

@@ -203,6 +203,7 @@ class Tall(Layout):
             if self.layout_opts.full_size > 1:
                 self.layout_opts.full_size -= 1
                 return True
+        return None
 
     def minimal_borders(self, all_windows: WindowList) -> Generator[BorderLine, None, None]:
         num = all_windows.num_groups

kitty/notify.py

@@ -218,3 +218,4 @@ def handle_notification_cmd(
         cmd = parse_osc_777(raw_data)
         notify_with_command(cmd, window_id, notify_implementation)
         return cmd
+    return None

kitty/options/utils.py

@@ -764,7 +764,7 @@ def kitten_alias(val: str) -> Iterable[Tuple[str, List[str]]]:
 def symbol_map(val: str) -> Iterable[Tuple[Tuple[int, int], str]]:
     parts = val.split()
 
-    def abort() -> Dict[Tuple[int, int], str]:
+    def abort() -> None:
         log_error(f'Symbol map: {val} is invalid, ignoring')
 
     if len(parts) < 2:

kitty/rc/close_tab.py

@@ -35,6 +35,7 @@ If specified close the tab of the window this command is run in, rather than the
         for tab in self.tabs_for_match_payload(boss, window, payload_get):
             if tab:
                 boss.close_tab_no_confirm(tab)
+        return None
 
 
 close_tab = CloseTab()

kitty/rc/close_window.py

@@ -34,6 +34,7 @@ If specified close the window this command is run in, rather than the active win
         for window in self.windows_for_match_payload(boss, window, payload_get):
             if window:
                 boss.close_window(window)
+        return None
 
 
 close_window = CloseWindow()

kitty/rc/create_marker.py

@@ -45,6 +45,7 @@ If specified apply marker to the window this command is run in, rather than the
         args = payload_get('marker_spec')
         for window in self.windows_for_match_payload(boss, window, payload_get):
             window.set_marker(args)
+        return None
 
 
 create_marker = CreateMarker()

kitty/rc/detach_tab.py

@@ -57,6 +57,7 @@ If specified detach the tab this command is run in, rather than the active tab.
 
         for tab in tabs:
             boss._move_tab_to(tab=tab, **kwargs)
+        return None
 
 
 detach_tab = DetachTab()

kitty/rc/detach_window.py

@@ -53,6 +53,7 @@ If specified detach the window this command is run in, rather than the active wi
         kwargs = {'target_os_window_id': newval} if target_tab_id is None else {'target_tab_id': target_tab_id}
         for window in windows:
             boss._move_window_to(window=window, **kwargs)
+        return None
 
 
 detach_window = DetachWindow()

kitty/rc/disable_ligatures.py

@@ -52,6 +52,7 @@ cause ligatures to be changed in all windows.
     def response_from_kitty(self, boss: Boss, window: Optional[Window], payload_get: PayloadGetType) -> ResponseType:
         windows = self.windows_for_payload(boss, window, payload_get)
         boss.disable_ligatures_in(windows, payload_get('strategy'))
+        return None
 # }}}
 
 

kitty/rc/env.py

@@ -43,6 +43,7 @@ class Env(RemoteCommand):
             else:
                 env.pop(k, None)
         set_default_env(env)
+        return None
 
 
 env = Env()

kitty/rc/focus_tab.py

@@ -41,6 +41,7 @@ using this option means that you will not be notified of failures.
             if tab:
                 boss.set_active_tab(tab)
                 break
+        return None
 
 
 focus_tab = FocusTab()

kitty/rc/focus_window.py

@@ -43,6 +43,7 @@ the command will exit with a success code.
                 if os_window_id:
                     focus_os_window(os_window_id, True)
                 break
+        return None
 
 
 focus_window = FocusWindow()

kitty/rc/goto_layout.py

@@ -47,6 +47,7 @@ class GotoLayout(RemoteCommand):
                     tab.goto_layout(payload_get('layout'), raise_exception=True)
                 except ValueError:
                     raise UnknownLayout('The layout {} is unknown or disabled'.format(payload_get('layout')))
+        return None
 
 
 goto_layout = GotoLayout()

kitty/rc/kitten.py

@@ -51,6 +51,7 @@ class Kitten(RemoteCommand):
                 break
         if isinstance(retval, (str, bool)):
             return retval
+        return None
 
 
 kitten = Kitten()

kitty/rc/last_used_layout.py

@@ -45,6 +45,7 @@ the command will exit with a success code.
         for tab in self.tabs_for_match_payload(boss, window, payload_get):
             if tab:
                 tab.last_used_layout()
+        return None
 
 
 last_used_layout = LastUsedLayout()

kitty/rc/remove_marker.py

@@ -34,6 +34,7 @@ If specified apply marker to the window this command is run in, rather than the
     def response_from_kitty(self, boss: Boss, window: Optional[Window], payload_get: PayloadGetType) -> ResponseType:
         for window in self.windows_for_match_payload(boss, window, payload_get):
             window.remove_marker()
+        return None
 
 
 remove_marker = RemoveMarker()

kitty/rc/resize_os_window.py

@@ -96,6 +96,7 @@ using this option means that you will not be notified of failures.
                     boss.toggle_fullscreen(os_window_id)
                 elif ac == 'toggle-maximized':
                     boss.toggle_maximized(os_window_id)
+        return None
 
 
 resize_os_window = ResizeOSWindow()

kitty/rc/scroll_window.py

@@ -69,6 +69,7 @@ class ScrollWindow(RemoteCommand):
                         func = getattr(window, f'scroll_{unit}_{direction}')
                         for i in range(abs(amt)):
                             func()
+        return None
 
 
 scroll_window = ScrollWindow()

kitty/rc/send_text.py

@@ -161,6 +161,7 @@ Do not send text to the active window, even if it is one of the matched windows.
                             window.write_to_child(kdata)
                     else:
                         window.write_to_child(data)
+        return None
 
 
 send_text = SendText()

kitty/rc/set_background_image.py

@@ -124,6 +124,7 @@ failed, the command will exit with a success code.
         except ValueError as err:
             err.hide_traceback = True  # type: ignore
             raise
+        return None
 
 
 set_background_image = SetBackgroundImage()

kitty/rc/set_background_opacity.py

@@ -53,6 +53,7 @@ cause colors to be changed in all windows.
         windows = self.windows_for_payload(boss, window, payload_get)
         for os_window_id in {w.os_window_id for w in windows}:
             boss._set_os_window_background_opacity(os_window_id, payload_get('opacity'))
+        return None
 
 
 set_background_opacity = SetBackgroundOpacity()

kitty/rc/set_colors.py

@@ -107,6 +107,7 @@ this option, any color arguments are ignored and --configured and --all are impl
             if default_bg_changed:
                 boss.default_bg_changed_for(w.id)
             w.refresh()
+        return None
 
 
 set_colors = SetColors()

kitty/rc/set_enabled_layouts.py

@@ -64,6 +64,7 @@ as well.
         for tab in tabs:
             if tab:
                 tab.set_enabled_layouts(layouts)
+        return None
 
 
 set_enabled_layouts = SetEnabledLayouts()

kitty/rc/set_font_size.py

@@ -49,6 +49,7 @@ the font size for any newly created OS Windows in the future.
         boss.change_font_size(
             payload_get('all'),
             payload_get('increment_op'), payload_get('size'))
+        return None
 
 
 set_font_size = SetFontSize()

kitty/rc/set_spacing.py

@@ -119,6 +119,7 @@ windows).
 
         for tab in dirtied_tabs.values():
             tab.relayout()
+        return None
 
 
 set_spacing = SetSpacing()

kitty/rc/set_tab_color.py

@@ -76,6 +76,7 @@ If specified close the tab this command is run in, rather than the active tab.
                 for k, v in s.items():
                     setattr(tab, k, v)
                 tab.mark_tab_bar_dirty()
+        return None
 
 
 set_tab_color = SetTabColor()

kitty/rc/set_tab_title.py

@@ -37,6 +37,7 @@ class SetTabTitle(RemoteCommand):
         for tab in self.tabs_for_match_payload(boss, window, payload_get):
             if tab:
                 tab.set_title(payload_get('title'))
+        return None
 
 
 set_tab_title = SetTabTitle()

kitty/rc/set_window_title.py

@@ -57,6 +57,7 @@ want to allow other programs to change it afterwards, use this option.
                     window.title_changed(payload_get('title'))
                 else:
                     window.set_title(payload_get('title'))
+        return None
 
 
 set_window_title = SetWindowTitle()

kitty/rc/signal_child.py

@@ -47,6 +47,7 @@ class SignalChild(RemoteCommand):
         for window in windows:
             if window:
                 window.signal_child(*signals)
+        return None
 
 
 signal_child = SignalChild()

kitty/shell_integration.py

@@ -61,7 +61,7 @@ def setup_bash_integration() -> None:
     setup_integration('bash', os.path.expanduser('~/.bashrc'))
 
 
-def atomic_symlink(destination: str, in_directory: str) -> str:
+def atomic_symlink(destination: str, in_directory: str) -> None:
     os.makedirs(in_directory, exist_ok=True)
     name = os.path.basename(destination)
     tmpname = os.path.join(in_directory, f'{name}-{os.getpid()}-{time.monotonic()}')
@@ -97,6 +97,7 @@ def get_supported_shell_name(path: str) -> Optional[str]:
     name = os.path.basename(path).split('.')[0].lower()
     if name in SUPPORTED_SHELLS:
         return name
+    return None
 
 
 @run_once

kitty/tab_bar.py

@@ -578,3 +578,4 @@ class TabBar:
             for i, (a, b) in enumerate(self.cell_ranges):
                 if a <= x <= b:
                     return i
+        return None

kitty/tabs.py

@@ -500,6 +500,7 @@ class Tab:  # {{{
     def get_nth_window(self, n: int) -> Optional[Window]:
         if self.windows:
             return self.current_layout.nth_window(self.windows, n)
+        return None
 
     @ac('win', '''
         Focus the nth window if positive or the previously active windows if negative
@@ -541,6 +542,7 @@ class Tab:  # {{{
 
         if groups:
             return groups[0]
+        return None
 
     def nth_active_window_id(self, n: int = 0) -> int:
         if n <= 0:
@@ -553,6 +555,7 @@ class Tab:  # {{{
         candidates = neighbors.get(which)
         if candidates:
             return self.most_recent_group(candidates)
+        return None
 
     @ac('win', '''
         Focus the neighboring window in the current tab
@@ -794,6 +797,7 @@ class TabManager:  # {{{
             delta = -1 if loc == 'left' else 1
             idx = (len(self.tabs) + self.active_tab_idx + delta) % len(self.tabs)
             return self.tabs[idx]
+        return None
 
     def goto_tab(self, tab_num: int) -> None:
         if tab_num >= len(self.tabs):
@@ -856,6 +860,7 @@ class TabManager:  # {{{
         t = self.active_tab
         if t is not None:
             return t.active_window
+        return None
 
     @property
     def number_of_windows_with_running_programs(self) -> int:
@@ -875,6 +880,7 @@ class TabManager:  # {{{
         for t in self.tabs:
             if t.id == tab_id:
                 return t
+        return None
 
     def move_tab(self, delta: int = 1) -> None:
         if len(self.tabs) > 1:

kitty/utils.py

@@ -61,6 +61,7 @@ def platform_window_id(os_window_id: int) -> Optional[int]:
         from .fast_data_types import x11_window_id
         with suppress(Exception):
             return x11_window_id(os_window_id)
+    return None
 
 
 def load_shaders(name: str, vertex_name: str = '', fragment_name: str = '') -> Tuple[str, str]:
@@ -284,6 +285,7 @@ def init_startup_notification(window_handle: Optional[int], startup_id: Optional
     except Exception:
         import traceback
         traceback.print_exc()
+    return None
 
 
 def end_startup_notification(ctx: Optional['StartupCtx']) -> None:
@@ -500,6 +502,7 @@ def resolve_editor_cmd(editor: str, shell_env: Mapping[str, str]) -> Optional[st
         q = shutil.which(editor_exe, path=shell_env['PATH'])
         if q:
             return patched(q)
+    return None
 
 
 def get_editor_from_env(env: Mapping[str, str]) -> Optional[str]:
@@ -509,6 +512,7 @@ def get_editor_from_env(env: Mapping[str, str]) -> Optional[str]:
             editor = resolve_editor_cmd(editor, env)
             if editor:
                 return editor
+    return None
 
 
 def get_editor_from_env_vars(opts: Optional[Options] = None) -> List[str]:

kitty/window.py

@@ -594,6 +594,7 @@ class Window:
         if not text:
             return True
         self.write_to_child(text)
+        return False
 
     @ac('debug', 'Show a dump of the current lines in the scrollback + screen with their line attributes')
     def dump_lines_with_attrs(self) -> None:

kitty/window_list.py

@@ -108,6 +108,7 @@ class WindowGroup:
         if self.windows:
             w: WindowType = self.windows[-1]
             return w.geometry
+        return None
 
     @property
     def is_visible_in_layout(self) -> bool:
@@ -195,6 +196,7 @@ class WindowList:
         for i, gr in enumerate(self.groups):
             if gr.id == group_id:
                 return self.set_active_group_idx(i)
+        return False
 
     def change_tab(self, tab: TabType) -> None:
         self.tabref = weakref.ref(tab)
@@ -241,32 +243,38 @@ class WindowList:
         for g in self.groups:
             if q in g:
                 return g
+        return None
 
     def group_idx_for_window(self, x: WindowOrId) -> Optional[int]:
         q = self.id_map[x] if isinstance(x, int) else x
         for i, g in enumerate(self.groups):
             if q in g:
                 return i
+        return None
 
     def windows_in_group_of(self, x: WindowOrId) -> Iterator[WindowType]:
         g = self.group_for_window(x)
         if g is not None:
             return iter(g)
+        return iter(())
 
     @property
     def active_group(self) -> Optional[WindowGroup]:
         with suppress(Exception):
             return self.groups[self.active_group_idx]
+        return None
 
     @property
     def active_window(self) -> Optional[WindowType]:
         with suppress(Exception):
             return self.id_map[self.groups[self.active_group_idx].active_window_id]
+        return None
 
     @property
     def active_group_base(self) -> Optional[WindowType]:
         with suppress(Exception):
             return self.id_map[self.groups[self.active_group_idx].base_window_id]
+        return None
 
     def set_active_window_group_for(self, x: WindowOrId) -> None:
         try:
@@ -350,6 +358,7 @@ class WindowList:
             n = max(0, min(n, self.num_groups - 1))
         if 0 <= n < self.num_groups:
             return self.id_map.get(self.groups[n].active_window_id)
+        return None
 
     def activate_next_window_group(self, delta: int) -> None:
         self.set_active_group_idx(wrap_increment(self.active_group_idx, self.num_groups, delta))

setup.cfg

@@ -22,7 +22,6 @@ warn_redundant_casts = True
 warn_unused_ignores = True
 warn_return_any = True
 warn_unreachable = True
-warn_no_return = False
 warn_unused_configs = True
 check_untyped_defs = True
 disallow_untyped_defs = True