chore: Enable Ruff's PERF checks and apply minor refactorings

pyproject.toml

@@ -243,7 +243,8 @@ select = [
     "C4",   # flake8-comprehensions
     "DTZ",  # flake8-datetimezs
     "T10",  # flake8-debugger
-    "EM",   # flake8-error-message
+    "EM",   # flake8-errmsg
+    "FA",   # flake8-future-annotations
     "ISC",  # flake8-implicit-str-concat
     "ICN",  # flake8-import-conventions
     "G",    # flake8-logging-format
@@ -254,6 +255,7 @@ select = [
     "Q",    # flake8-quotes
     "RSE",  # flake8-raise
     "RET",  # flake8-return
+    # "SLF",  # flake8-self
     "SIM",  # flake8-simplify
     "TID",  # flake8-tidy-imports
     "TCH",  # flake8-type-checking
@@ -265,6 +267,7 @@ select = [
     "PLE",  # pylint (error)
     "PLR",  # pylint (refactor)
     "PLW",  # pylint (warning)
+    "PERF", # perflint
     "RUF",  # ruff
 ]
 src = ["samples", "singer_sdk", "tests"]

singer_sdk/tap_base.py

@@ -408,7 +408,7 @@ def load_state(self, state: dict[str, t.Any]) -> None:
 
     def _reset_state_progress_markers(self) -> None:
         """Clear prior jobs' progress markers at beginning of sync."""
-        for _, state in self.state.get("bookmarks", {}).items():
+        for state in self.state.get("bookmarks", {}).values():
             _state.reset_state_progress_markers(state)
             for partition_state in state.get("partitions", []):
                 _state.reset_state_progress_markers(partition_state)
@@ -667,14 +667,11 @@ def discover_streams(self) -> list[Stream]:
         Returns:
             List of discovered Stream objects.
         """
-        result: list[Stream] = []
-        for catalog_entry in self.catalog_dict["streams"]:
-            result.append(
-                self.default_stream_class(
-                    tap=self,
-                    catalog_entry=catalog_entry,
-                    connector=self.tap_connector,
-                ),
+        return [
+            self.default_stream_class(
+                tap=self,
+                catalog_entry=catalog_entry,
+                connector=self.tap_connector,
             )
-
-        return result
+            for catalog_entry in self.catalog_dict["streams"]
+        ]

singer_sdk/testing/tap_tests.py

@@ -185,12 +185,12 @@ def test(self) -> None:
         Raises:
             AssertionError: if value cannot be parsed as a datetime.
         """
-        for v in self.non_null_attribute_values:
-            try:
+        try:
+            for v in self.non_null_attribute_values:
                 error_message = f"Unable to parse value ('{v}') with datetime parser."
                 assert parser.parse(v), error_message
-            except parser.ParserError as e:
-                raise AssertionError(error_message) from e
+        except parser.ParserError as e:
+            raise AssertionError(error_message) from e
 
     @classmethod
     def evaluate(

singer_sdk/typing.py

@@ -58,7 +58,10 @@
 import typing as t
 
 import sqlalchemy
-from jsonschema import ValidationError, Validator, validators
+from jsonschema import ValidationError, validators
+
+if t.TYPE_CHECKING:
+    from jsonschema.protocols import Validator
 
 from singer_sdk.helpers._typing import (
     JSONSCHEMA_ANNOTATION_SECRET,