refactor: Move type-only imports to type-checking blocks (TC001)

- Standardise type-checking imports to `from typing import TYPE_CHECKING`

Unused imports add a performance overhead at runtime, and risk creating
import cycles. If an import is only used in typing-only contexts, it can
instead be imported conditionally under an if TYPE_CHECKING: block to
minimize runtime overhead.

https://docs.astral.sh/ruff/rules/typing-only-first-party-import/#why-is-this-bad

Author: kieran-ryan

pyproject.toml

@@ -61,13 +61,14 @@ build-backend = "poetry.core.masonry.api"
 line-length = 120
 target-version = "py39"
 lint.select = [
-    "B",  # flake8-bugbear
-    "E4",  # pycodestyle - error - import
-    "E7",  # pycodestyle - error - statement
-    "E9",  # pycodestyle - error - runtime
-    "F",  # pyflakes
-    "I",  # isort
-    "UP",  # pyupgrade
+    "B",     # flake8-bugbearBugbear
+    "E4",    # pycodestyle - error - import
+    "E7",    # pycodestyle - error - statement
+    "E9",    # pycodestyle - error - runtime
+    "F",     # pyflakes
+    "I",     # isort
+    "TC",    # flake8-type-checking
+    "UP",    # pyupgrade
 ]
 lint.isort.required-imports = [
     "from __future__ import annotations",

src/pytest_bdd/compat.py

@@ -1,12 +1,16 @@
 from __future__ import annotations
 
-from collections.abc import Sequence
 from importlib.metadata import version
+from typing import TYPE_CHECKING
 
 from _pytest.fixtures import FixtureDef, FixtureManager, FixtureRequest
-from _pytest.nodes import Node
 from packaging.version import parse as parse_version
 
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+    from _pytest.nodes import Node
+
 pytest_version = parse_version(version("pytest"))
 
 __all__ = ["getfixturedefs", "inject_fixture"]

src/pytest_bdd/feature.py

@@ -28,10 +28,13 @@
 
 import glob
 import os.path
-from collections.abc import Iterable
+from typing import TYPE_CHECKING
 
 from .parser import Feature, FeatureParser
 
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
 # Global features dictionary
 features: dict[str, Feature] = {}
 

src/pytest_bdd/generation.py

@@ -12,7 +12,6 @@
 
 from .compat import getfixturedefs
 from .feature import get_features
-from .parser import Feature, ScenarioTemplate, Step
 from .scenario import (
     inject_fixturedefs_for_step,
     make_python_docstring,
@@ -32,6 +31,8 @@
     from _pytest.main import Session
     from _pytest.nodes import Node
 
+    from .parser import Feature, ScenarioTemplate, Step
+
 
 template_lookup = TemplateLookup(directories=[os.path.join(os.path.dirname(__file__), "templates")])
 

src/pytest_bdd/gherkin_parser.py

@@ -3,17 +3,17 @@
 import linecache
 import re
 import textwrap
-import typing
-from collections.abc import Mapping, Sequence
 from dataclasses import dataclass, field
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 from gherkin.errors import CompositeParserException  # type: ignore
 from gherkin.parser import Parser  # type: ignore
 
 from . import exceptions
 
-if typing.TYPE_CHECKING:
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+
     from typing_extensions import Self
 
 

src/pytest_bdd/gherkin_terminal_reporter.py

@@ -1,12 +1,12 @@
 from __future__ import annotations
 
-import typing
+from typing import TYPE_CHECKING
 
 from _pytest.terminal import TerminalReporter
 
 from .reporting import test_report_context_registry
 
-if typing.TYPE_CHECKING:
+if TYPE_CHECKING:
     from _pytest.config import Config
     from _pytest.config.argparsing import Parser
     from _pytest.reports import TestReport

src/pytest_bdd/hooks.py

@@ -1,11 +1,15 @@
 from __future__ import annotations
 
-from collections.abc import Callable
+from typing import TYPE_CHECKING
 
 import pytest
-from _pytest.fixtures import FixtureRequest
 
-from pytest_bdd.parser import Feature, Scenario, Step
+if TYPE_CHECKING:
+    from collections.abc import Callable
+
+    from _pytest.fixtures import FixtureRequest
+
+    from pytest_bdd.parser import Feature, Scenario, Step
 
 """Pytest-bdd pytest hooks."""
 

src/pytest_bdd/parser.py

@@ -5,8 +5,8 @@
 import re
 import textwrap
 from collections import OrderedDict
-from collections.abc import Generator, Iterable, Mapping, Sequence
 from dataclasses import dataclass, field
+from typing import TYPE_CHECKING
 
 from .exceptions import StepError
 from .gherkin_parser import Background as GherkinBackground
@@ -18,6 +18,9 @@
 from .gherkin_parser import Tag as GherkinTag
 from .types import STEP_TYPE_BY_PARSER_KEYWORD
 
+if TYPE_CHECKING:
+    from collections.abc import Generator, Iterable, Mapping, Sequence
+
 PARAM_RE = re.compile(r"<(.+?)>")
 
 

src/pytest_bdd/plugin.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-from collections.abc import Generator
 from typing import TYPE_CHECKING, Callable, TypeVar, cast
 
 import pytest
@@ -12,6 +11,8 @@
 from .utils import CONFIG_STACK
 
 if TYPE_CHECKING:
+    from collections.abc import Generator
+
     from _pytest.config import Config, PytestPluginManager
     from _pytest.config.argparsing import Parser
     from _pytest.fixtures import FixtureRequest

src/pytest_bdd/scenario.py

@@ -17,7 +17,6 @@
 import logging
 import os
 import re
-from collections.abc import Iterable, Iterator
 from inspect import signature
 from typing import TYPE_CHECKING, Callable, TypeVar, cast
 from weakref import WeakKeyDictionary
@@ -39,6 +38,8 @@
 )
 
 if TYPE_CHECKING:
+    from collections.abc import Iterable, Iterator
+
     from _pytest.mark.structures import ParameterSet
     from _pytest.nodes import Node