chore: Enable TCH Ruff checks (#1514)

pyproject.toml

@@ -239,6 +239,7 @@ select = [
     "RSE",  # flake8-raise
     "RET",  # flake8-return
     "SIM",  # flake8-simplify
+    "TCH",  # flake8-type-checking
 ]
 src = ["samples", "singer_sdk", "tests"]
 target-version = "py37"

samples/sample_mapper/mapper.py

@@ -2,15 +2,17 @@
 
 from __future__ import annotations
 
-from pathlib import PurePath
-from typing import Generator
+from typing import TYPE_CHECKING, Generator
 
 import singer_sdk._singerlib as singer
 import singer_sdk.typing as th
 from singer_sdk.helpers._util import utc_now
 from singer_sdk.mapper import PluginMapper
 from singer_sdk.mapper_base import InlineMapper
 
+if TYPE_CHECKING:
+    from pathlib import PurePath
+
 
 class StreamTransform(InlineMapper):
     """A map transformer which implements the Stream Maps capability."""

singer_sdk/_singerlib/messages.py

@@ -6,11 +6,13 @@
 import sys
 import typing as t
 from dataclasses import asdict, dataclass, field
-from datetime import datetime
 
 import pytz
 import simplejson as json
 
+if t.TYPE_CHECKING:
+    from datetime import datetime
+
 
 class SingerMessageType(str, enum.Enum):
     """Singer specification message types."""

singer_sdk/authenticators.py

@@ -3,11 +3,10 @@
 from __future__ import annotations
 
 import base64
-import logging
 import math
 from datetime import datetime, timedelta
 from types import MappingProxyType
-from typing import Any, Mapping
+from typing import TYPE_CHECKING, Any, Mapping
 from urllib.parse import parse_qs, urlencode, urlsplit, urlunsplit
 
 import jwt
@@ -16,7 +15,11 @@
 from cryptography.hazmat.primitives import serialization
 
 from singer_sdk.helpers._util import utc_now
-from singer_sdk.streams import Stream as RESTStreamBase
+
+if TYPE_CHECKING:
+    import logging
+
+    from singer_sdk.streams import Stream as RESTStreamBase
 
 
 def _add_parameters(initial_url: str, extra_parameters: dict) -> str:

singer_sdk/connectors/sql.py

@@ -7,16 +7,18 @@
 from contextlib import contextmanager
 from datetime import datetime
 from functools import lru_cache
-from typing import Any, Iterable, Iterator, cast
+from typing import TYPE_CHECKING, Any, Iterable, Iterator, cast
 
 import sqlalchemy
 from sqlalchemy.engine import Engine
-from sqlalchemy.engine.reflection import Inspector
 
 from singer_sdk import typing as th
 from singer_sdk._singerlib import CatalogEntry, MetadataMapping, Schema
 from singer_sdk.exceptions import ConfigValidationError
 
+if TYPE_CHECKING:
+    from sqlalchemy.engine.reflection import Inspector
+
 
 class SQLConnector:
     """Base class for SQLAlchemy-based connectors.

singer_sdk/exceptions.py

@@ -2,7 +2,10 @@
 
 from __future__ import annotations
 
-import requests
+import typing as t
+
+if t.TYPE_CHECKING:
+    import requests
 
 
 class ConfigValidationError(Exception):

singer_sdk/helpers/_catalog.py

@@ -3,14 +3,17 @@
 from __future__ import annotations
 
 from copy import deepcopy
-from logging import Logger
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 from memoization import cached
 
-from singer_sdk._singerlib import Catalog, SelectionMask
 from singer_sdk.helpers._typing import is_object_type
 
+if TYPE_CHECKING:
+    from logging import Logger
+
+    from singer_sdk._singerlib import Catalog, SelectionMask
+
 _MAX_LRU_CACHE = 500
 
 

singer_sdk/helpers/_resources.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import sys
-from types import ModuleType
-from typing import cast
+from typing import TYPE_CHECKING, cast
+
+if TYPE_CHECKING:
+    from types import ModuleType
 
 if sys.version_info < (3, 9):
     import importlib_resources

singer_sdk/helpers/_state.py

@@ -2,12 +2,14 @@
 
 from __future__ import annotations
 
-import datetime
-from typing import Any, Callable, cast
+from typing import TYPE_CHECKING, Any, Callable, cast
 
 from singer_sdk.exceptions import InvalidStreamSortException
 from singer_sdk.helpers._typing import to_json_compatible
 
+if TYPE_CHECKING:
+    import datetime
+
 PROGRESS_MARKERS = "progress_markers"
 PROGRESS_MARKER_NOTE = "Note"
 SIGNPOST_MARKER = "replication_key_signpost"

singer_sdk/helpers/_typing.py

@@ -4,13 +4,15 @@
 
 import copy
 import datetime
-import logging
 from enum import Enum
 from functools import lru_cache
-from typing import Any, cast
+from typing import TYPE_CHECKING, Any, cast
 
 import pendulum
 
+if TYPE_CHECKING:
+    import logging
+
 _MAX_TIMESTAMP = "9999-12-31 23:59:59.999999"
 _MAX_TIME = "23:59:59.999999"
 JSONSCHEMA_ANNOTATION_SECRET = "secret"

singer_sdk/helpers/jsonpath.py

@@ -2,12 +2,14 @@
 
 from __future__ import annotations
 
-from typing import Any, Generator
+from typing import TYPE_CHECKING, Any, Generator
 
-import jsonpath_ng
 import memoization
 from jsonpath_ng.ext import parse
 
+if TYPE_CHECKING:
+    import jsonpath_ng
+
 
 def extract_jsonpath(expression: str, input: dict | list) -> Generator[Any, None, None]:
     """Extract records from an input based on a JSONPath expression.

singer_sdk/mapper.py

@@ -10,10 +10,8 @@
 import datetime
 import hashlib
 import logging
-import sys
-from typing import Any, Callable, Dict, Union
+from typing import TYPE_CHECKING, Any, Callable, Dict, Union
 
-from singer_sdk._singerlib.catalog import Catalog
 from singer_sdk.exceptions import MapExpressionError, StreamMapConfigError
 from singer_sdk.helpers import _simpleeval as simpleeval
 from singer_sdk.helpers._catalog import get_selected_schema
@@ -33,10 +31,15 @@
     StringType,
 )
 
-if sys.version_info >= (3, 10):
-    from typing import TypeAlias
-else:
-    from typing_extensions import TypeAlias
+if TYPE_CHECKING:
+    import sys
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
+
+    from singer_sdk._singerlib.catalog import Catalog
 
 
 MAPPER_ELSE_OPTION = "__else__"

singer_sdk/mapper_base.py

@@ -3,8 +3,7 @@
 from __future__ import annotations
 
 import abc
-from io import FileIO
-from typing import Callable, Iterable
+from typing import TYPE_CHECKING, Callable, Iterable
 
 import click
 
@@ -16,6 +15,9 @@
 from singer_sdk.io_base import SingerReader
 from singer_sdk.plugin_base import PluginBase
 
+if TYPE_CHECKING:
+    from io import FileIO
+
 
 class InlineMapper(PluginBase, SingerReader, metaclass=abc.ABCMeta):
     """Abstract base class for inline mappers."""

singer_sdk/metrics.py

@@ -11,13 +11,15 @@
 from dataclasses import asdict, dataclass, field
 from pathlib import Path
 from time import time
-from types import TracebackType
-from typing import Any, Generic, Mapping, TypeVar
+from typing import TYPE_CHECKING, Any, Generic, Mapping, TypeVar
 
 import yaml
 
 from singer_sdk.helpers._resources import Traversable, get_package_files
 
+if TYPE_CHECKING:
+    from types import TracebackType
+
 DEFAULT_LOG_INTERVAL = 60.0
 METRICS_LOGGER_NAME = __name__
 METRICS_LOG_LEVEL_SETTING = "metrics_log_level"

singer_sdk/pagination.py

@@ -4,18 +4,19 @@
 
 import sys
 from abc import ABCMeta, abstractmethod
-from typing import Any, Generic, Iterable, Optional, TypeVar
+from typing import TYPE_CHECKING, Any, Generic, Iterable, Optional, TypeVar
 from urllib.parse import ParseResult, urlparse
 
-from requests import Response
-
 from singer_sdk.helpers.jsonpath import extract_jsonpath
 
 if sys.version_info >= (3, 8):
     from typing import Protocol
 else:
     from typing_extensions import Protocol
 
+if TYPE_CHECKING:
+    from requests import Response
+
 T = TypeVar("T")
 TPageToken = TypeVar("TPageToken")
 

singer_sdk/plugin_base.py

@@ -9,7 +9,7 @@
 from collections import OrderedDict
 from pathlib import PurePath
 from types import MappingProxyType
-from typing import Any, Callable, Mapping, cast
+from typing import TYPE_CHECKING, Any, Callable, Mapping, cast
 
 import click
 from jsonschema import Draft7Validator
@@ -27,9 +27,11 @@
     CapabilitiesEnum,
     PluginCapabilities,
 )
-from singer_sdk.mapper import PluginMapper
 from singer_sdk.typing import extend_validator_with_defaults
 
+if TYPE_CHECKING:
+    from singer_sdk.mapper import PluginMapper
+
 SDK_PACKAGE_NAME = "singer_sdk"
 
 

singer_sdk/sinks/core.py

@@ -8,9 +8,8 @@
 import time
 from gzip import GzipFile
 from gzip import open as gzip_open
-from logging import Logger
 from types import MappingProxyType
-from typing import IO, Any, Mapping, Sequence
+from typing import IO, TYPE_CHECKING, Any, Mapping, Sequence
 
 from dateutil import parser
 from jsonschema import Draft7Validator, FormatChecker
@@ -27,7 +26,11 @@
     get_datelike_property_type,
     handle_invalid_timestamp_in_record,
 )
-from singer_sdk.plugin_base import PluginBase
+
+if TYPE_CHECKING:
+    from logging import Logger
+
+    from singer_sdk.plugin_base import PluginBase
 
 JSONSchemaValidator = Draft7Validator
 

singer_sdk/sinks/sql.py

@@ -6,19 +6,22 @@
 from collections import defaultdict
 from copy import copy
 from textwrap import dedent
-from typing import Any, Iterable
+from typing import TYPE_CHECKING, Any, Iterable
 
 import sqlalchemy
 from pendulum import now
-from sqlalchemy.sql import Executable
 from sqlalchemy.sql.expression import bindparam
 
 from singer_sdk.connectors import SQLConnector
 from singer_sdk.exceptions import ConformedNameClashException
 from singer_sdk.helpers._conformers import replace_leading_digit
-from singer_sdk.plugin_base import PluginBase
 from singer_sdk.sinks.batch import BatchSink
 
+if TYPE_CHECKING:
+    from sqlalchemy.sql import Executable
+
+    from singer_sdk.plugin_base import PluginBase
+
 
 class SQLSink(BatchSink):
     """SQL-type sink type."""

singer_sdk/streams/core.py

@@ -8,11 +8,19 @@
 import gzip
 import itertools
 import json
-import logging
 from os import PathLike
 from pathlib import Path
 from types import MappingProxyType
-from typing import Any, Generator, Iterable, Iterator, Mapping, TypeVar, cast
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Generator,
+    Iterable,
+    Iterator,
+    Mapping,
+    TypeVar,
+    cast,
+)
 from uuid import uuid4
 
 import pendulum
@@ -46,7 +54,11 @@
 )
 from singer_sdk.helpers._util import utc_now
 from singer_sdk.mapper import RemoveRecordTransform, SameRecordTransform, StreamMap
-from singer_sdk.plugin_base import PluginBase as TapBaseClass
+
+if TYPE_CHECKING:
+    import logging
+
+    from singer_sdk.plugin_base import PluginBase as TapBaseClass
 
 # Replication methods
 REPLICATION_FULL_TABLE = "FULL_TABLE"