fix: Use built-in RecordsWithoutSchemaException (#207)

Instead of using a generic exception and relying on an error message,
use the built-in RecordsWithoutSchemaException for when a record message
arrives before its stream's schema message.

Closes #148

target_postgres/target.py

@@ -3,7 +3,6 @@
 
 from pathlib import PurePath
 
-import jsonschema
 from singer_sdk import typing as th
 from singer_sdk.target_base import SQLTarget
 
@@ -320,20 +319,3 @@ def max_parallelism(self) -> int:
         """
         # https://github.com/MeltanoLabs/target-postgres/issues/3
         return 1
-
-    def _process_record_message(self, message_dict: dict) -> None:
-        """Process a RECORD message.
-
-        Args:
-            message_dict: TODO
-        """
-        stream_name = message_dict["stream"]
-        if self.mapper.stream_maps.get(stream_name) is None:
-            raise Exception(f"Schema message has not been sent for {stream_name}")
-        try:
-            super()._process_record_message(message_dict)
-        except jsonschema.exceptions.ValidationError as e:
-            self.logger.error(
-                f"Exception is being thrown for stream_name: {stream_name}"
-            )
-            raise e

target_postgres/tests/test_standard_target.py

@@ -198,16 +198,6 @@ def test_aapl_to_postgres(postgres_config):
     sync_end_to_end(tap, target)
 
 
-def test_record_before_schema(postgres_target):
-    with pytest.raises(Exception) as e:
-        file_name = "record_before_schema.singer"
-        singer_file_to_target(file_name, postgres_target)
-
-    assert (
-        str(e.value) == "Schema message has not been sent for test_record_before_schema"
-    )
-
-
 def test_invalid_schema(postgres_target):
     with pytest.raises(Exception) as e:
         file_name = "invalid_schema.singer"