Move type-only imports into TYPE_CHECKING blocks

.gitignore

@@ -1,4 +1,5 @@
 # caches
+.DS_Store
 __pycache__
 .mypy_cache
 

pyproject.toml

@@ -21,7 +21,8 @@ build-backend = "hatchling.build"
 lint = [
     "pydocstyle>=6.3.0",
     "ruff>=0.17.1",
-    "sublime-text-stubs>=1.4200.0",
+    "sublime-text-stubs>=4200.1",
+    "typing-extensions>=4.13.2",
 ]
 
 [tool.hatch.build.targets.sdist]
@@ -59,3 +60,10 @@ exclude = [
 ]
 line-length = 100
 target-version = "py38"
+
+[tool.ruff.lint]
+extend-select = ["TC"]
+
+[tool.ruff.lint.flake8-type-checking]
+# `sublime` and `sublime_plugin` are always available at runtime.
+exempt-modules = ["typing", "sublime", "sublime_plugin"]

sublime_lib/activity_indicator.py

@@ -3,14 +3,18 @@
 from abc import ABCMeta, abstractmethod
 from enum import IntEnum
 from threading import Lock
-from types import TracebackType
+from typing import TYPE_CHECKING
 from uuid import uuid4
 
 import sublime
-from typing_extensions import Self
 
 from ._util.weak_method import weak_method
 
+if TYPE_CHECKING:
+    from types import TracebackType
+
+    from typing_extensions import Self
+
 __all__ = ["ActivityIndicator"]
 
 

sublime_lib/flags.py

@@ -33,17 +33,19 @@
 import re
 from enum import EnumMeta, IntEnum, IntFlag
 from inspect import cleandoc, getdoc
-from typing import Callable
+from typing import TYPE_CHECKING, Callable
 
 import sublime
-from typing_extensions import Self
 
 from ._util.enum import (
     ExtensibleConstructorMeta,
     construct_union,
     construct_with_alternatives,
 )
 
+if TYPE_CHECKING:
+    from typing_extensions import Self
+
 __all__ = [
     "CompletionOptions",
     "DialogResult",

sublime_lib/resource_path.py

@@ -4,13 +4,16 @@
 import posixpath
 from abc import ABCMeta, abstractmethod
 from collections import OrderedDict
-from collections.abc import Iterable
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import sublime
 
 from ._util.glob import get_glob_matcher
 
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
 __all__ = ["ResourcePath"]
 
 

sublime_lib/view_stream.py

@@ -1,15 +1,17 @@
 from __future__ import annotations
 
-from collections.abc import Generator
 from contextlib import contextmanager
 from io import SEEK_CUR, SEEK_END, SEEK_SET
-from typing import Any, TextIO
+from typing import TYPE_CHECKING, Any, TextIO
 
 import sublime
 from sublime import Region
 
 from ._util.guard import define_guard
 
+if TYPE_CHECKING:
+    from collections.abc import Generator
+
 
 @define_guard
 @contextmanager