chore: Enable TCH Ruff rule (#444)

Author: edgarrmondragon

pyproject.toml

@@ -96,6 +96,7 @@ select = [
   "ICN",  # flake8-import-conventions
   "RET",  # flake8-return
   "SIM",  # flake8-simplify
+  "TCH",  # flake8-type-checking
   "PERF", # Perflint
   "RUF",  # ruff
 ]

target_postgres/connector.py

@@ -375,7 +375,7 @@ def create_empty_table(  # type: ignore[override]
 
         Args:
             table_name: the target table name.
-            meta: the SQLAchemy metadata object.
+            meta: the SQLAlchemy metadata object.
             schema: the JSON schema for the new table.
             connection: the database connection.
             primary_keys: list of key properties.
@@ -574,7 +574,7 @@ def _adapt_column_type(  # type: ignore[override]
             return
 
         # Not the same type, generic type or compatible types
-        # calling merge_sql_types for assistnace
+        # calling merge_sql_types for assistance
         compatible_sql_type = self.merge_sql_types([current_type, sql_type])
 
         if str(compatible_sql_type) == str(current_type):

target_postgres/sinks.py

@@ -8,13 +8,13 @@
 
 import sqlalchemy as sa
 from singer_sdk.sinks import SQLSink
-from sqlalchemy.sql import Executable
 from sqlalchemy.sql.expression import bindparam
 
 from target_postgres.connector import PostgresConnector
 
 if t.TYPE_CHECKING:
     from singer_sdk.connectors.sql import FullyQualifiedName
+    from sqlalchemy.sql import Executable
 
 
 class PostgresSink(SQLSink):
@@ -52,10 +52,8 @@ def setup(self) -> None:
         This method is called on Sink creation, and creates the required Schema and
         Table entities in the target database.
         """
-        if self.key_properties is None or self.key_properties == []:
-            self.append_only = True
-        else:
-            self.append_only = False
+        self.append_only = self.key_properties is None or self.key_properties == []
+
         if self.schema_name:
             self.connector.prepare_schema(self.schema_name)
         with self.connector._connect() as connection, connection.begin():
@@ -165,7 +163,7 @@ def bulk_insert_records(  # type: ignore[override]
                 for column in columns:
                     insert_record[column.name] = record.get(column.name)
                 # No need to check for a KeyError here because the SDK already
-                # guaruntees that all key properties exist in the record.
+                # guarantees that all key properties exist in the record.
                 primary_key_value = "".join([str(record[key]) for key in primary_keys])
                 insert_records[primary_key_value] = insert_record
             data_to_insert = list(insert_records.values())
@@ -296,7 +294,7 @@ def schema_name(self) -> str | None:
         Returns:
             The target schema name.
         """
-        # Look for a default_target_scheme in the configuraion fle
+        # Look for a default_target_scheme in the configuration fle
         default_target_schema: str = self.config.get("default_target_schema", None)
         parts = self.stream_name.split("-")
 

target_postgres/target.py

@@ -2,13 +2,16 @@
 
 from __future__ import annotations
 
-from pathlib import PurePath
+import typing as t
 
 from singer_sdk import typing as th
 from singer_sdk.target_base import SQLTarget
 
 from target_postgres.sinks import PostgresSink
 
+if t.TYPE_CHECKING:
+    from pathlib import PurePath
+
 
 class TargetPostgres(SQLTarget):
     """Target for Postgres."""