feat(lint): enable ruff TCH (flake8-type-checking) rules (#1125)

disnake/ext/commands/common_bot_base.py

@@ -4,6 +4,7 @@
 
 import asyncio
 import collections.abc
+import importlib.machinery
 import importlib.util
 import logging
 import os
@@ -19,8 +20,6 @@
 from .cog import Cog
 
 if TYPE_CHECKING:
-    import importlib.machinery
-
     from ._types import CoroFunc
     from .bot import AutoShardedBot, AutoShardedInteractionBot, Bot, InteractionBot
     from .help import HelpCommand

docs/extensions/attributetable.py

@@ -14,12 +14,13 @@
 from sphinx.util.docutils import SphinxDirective
 
 if TYPE_CHECKING:
-    from _types import SphinxExtensionMeta
     from sphinx.application import Sphinx
     from sphinx.environment import BuildEnvironment
     from sphinx.util.typing import OptionSpec
     from sphinx.writers.html import HTMLTranslator
 
+    from ._types import SphinxExtensionMeta
+
 
 class attributetable(nodes.General, nodes.Element):
     pass

docs/extensions/builder.py

@@ -8,12 +8,13 @@
 from sphinx.environment.adapters.indexentries import IndexEntries
 
 if TYPE_CHECKING:
-    from _types import SphinxExtensionMeta
     from docutils import nodes
     from sphinx.application import Sphinx
     from sphinx.config import Config
     from sphinx.writers.html5 import HTML5Translator
 
+    from ._types import SphinxExtensionMeta
+
 if TYPE_CHECKING:
     translator_base = HTML5Translator
 else:

docs/extensions/exception_hierarchy.py

@@ -7,10 +7,11 @@
 from docutils.parsers.rst import Directive
 
 if TYPE_CHECKING:
-    from _types import SphinxExtensionMeta
     from sphinx.application import Sphinx
     from sphinx.writers.html import HTMLTranslator
 
+    from ._types import SphinxExtensionMeta
+
 
 class exception_hierarchy(nodes.General, nodes.Element):
     pass

docs/extensions/fulltoc.py

@@ -31,7 +31,6 @@
 
 from typing import TYPE_CHECKING, List, cast
 
-from _types import SphinxExtensionMeta
 from docutils import nodes
 from sphinx import addnodes
 
@@ -40,6 +39,8 @@
     from sphinx.builders.html import StandaloneHTMLBuilder
     from sphinx.environment import BuildEnvironment
 
+    from ._types import SphinxExtensionMeta
+
 # {prefix: index_doc} mapping
 # Any document that matches `prefix` will use `index_doc`'s toctree instead.
 GROUPED_SECTIONS = {"api/": "api/index", "ext/commands/api/": "ext/commands/api/index"}

docs/extensions/nitpick_file_ignorer.py

@@ -7,9 +7,10 @@
 from sphinx.util import logging as sphinx_logging
 
 if TYPE_CHECKING:
-    from _types import SphinxExtensionMeta
     from sphinx.application import Sphinx
 
+    from ._types import SphinxExtensionMeta
+
 
 class NitpickFileIgnorer(logging.Filter):
     def __init__(self, app: Sphinx) -> None:

docs/extensions/redirects.py

@@ -1,13 +1,16 @@
 # SPDX-License-Identifier: MIT
+from __future__ import annotations
 
 import json
 from pathlib import Path
-from typing import Dict
+from typing import TYPE_CHECKING, Dict
 
-from _types import SphinxExtensionMeta
 from sphinx.application import Sphinx
 from sphinx.util.fileutil import copy_asset_file
 
+if TYPE_CHECKING:
+    from ._types import SphinxExtensionMeta
+
 SCRIPT_PATH = "_templates/api_redirect.js_t"
 
 

docs/extensions/resourcelinks.py

@@ -10,12 +10,13 @@
 from sphinx.util.nodes import split_explicit_title
 
 if TYPE_CHECKING:
-    from _types import SphinxExtensionMeta
     from docutils.nodes import Node, system_message
     from docutils.parsers.rst.states import Inliner
     from sphinx.application import Sphinx
     from sphinx.util.typing import RoleFunction
 
+    from ._types import SphinxExtensionMeta
+
 
 def make_link_role(resource_links: Dict[str, str]) -> RoleFunction:
     def role(

pyproject.toml

@@ -149,7 +149,7 @@ select = [
     # "RET", # flake8-return
     # "SIM", # flake8-simplify
     "TID251", # flake8-tidy-imports, replaces S404
-    # "TCH", # flake8-type-checking
+    "TCH",    # flake8-type-checking
     "RUF",    # ruff specific exceptions
     "PT",     # flake8-pytest-style
     "Q",      # flake8-quotes
@@ -198,6 +198,13 @@ ignore = [
     # outer loop variables are overwritten by inner assignment target, these are mostly intentional
     "PLW2901",
 
+    # ignore imports that could be moved into type-checking blocks
+    # (no real advantage other than possibly avoiding cycles,
+    # but can be dangerous in places where we need to parse signatures)
+    "TCH001",
+    "TCH002",
+    "TCH003",
+
     # temporary disables, to fix later
     "D205",   # blank line required between summary and description
     "D401",   # first line of docstring should be in imperative mood

tests/ext/commands/test_core.py

@@ -1,20 +1,10 @@
 # SPDX-License-Identifier: MIT
 
-from typing import TYPE_CHECKING
+from typing_extensions import assert_type
 
 from disnake.ext import commands
 from tests.helpers import reveal_type
 
-if TYPE_CHECKING:
-    from typing_extensions import assert_type
-
-    # NOTE: using undocumented `expected_text` parameter of pyright instead of `assert_type`,
-    # as `assert_type` can't handle bound ParamSpecs
-    reveal_type(
-        42,  # type: ignore
-        expected_text="str",  # type: ignore
-    )
-
 
 class CustomContext(commands.Context):
     ...

tests/helpers.py

@@ -16,6 +16,15 @@ def reveal_type(*args, **kwargs) -> None:
         raise RuntimeError
 
 
+if TYPE_CHECKING:
+    # NOTE: using undocumented `expected_text` parameter of pyright instead of `assert_type`,
+    # as `assert_type` can't handle bound ParamSpecs
+    reveal_type(
+        42,  # type: ignore  # suppress "revealed type is ..." output
+        expected_text="str",  # type: ignore  # ensure the functionality we want still works as expected
+    )
+
+
 CallableT = TypeVar("CallableT", bound=Callable)
 
 

tests/ui/test_action_row.py

@@ -4,17 +4,20 @@
 from unittest import mock
 
 import pytest
+from typing_extensions import assert_type
 
 import disnake
-from disnake.ui import ActionRow, Button, StringSelect, TextInput, WrappedComponent
+from disnake.ui import (
+    ActionRow,
+    Button,
+    MessageUIComponent,
+    ModalUIComponent,
+    StringSelect,
+    TextInput,
+    WrappedComponent,
+)
 from disnake.ui.action_row import components_to_dict, components_to_rows
 
-if TYPE_CHECKING:
-    from typing_extensions import assert_type
-
-    from disnake.ui import MessageUIComponent, ModalUIComponent
-
-
 button1 = Button()
 button2 = Button()
 button3 = Button()
@@ -133,9 +136,8 @@ def test_with_components(self) -> None:
         row_msg = ActionRow.with_message_components()
         assert list(row_msg.children) == []
 
-        if TYPE_CHECKING:
-            assert_type(row_modal, ActionRow[ModalUIComponent])
-            assert_type(row_msg, ActionRow[MessageUIComponent])
+        assert_type(row_modal, ActionRow[ModalUIComponent])
+        assert_type(row_msg, ActionRow[MessageUIComponent])
 
     def test_rows_from_message(self) -> None:
         rows = [