fix: use interface in logic, not concrete dal type (#607)

Author: ran-isenberg

poetry.lock

@@ -1,5 +1,5 @@
 import uuid
-
+from functools import lru_cache
 import boto3
 from botocore.exceptions import ClientError
 from cachetools import TTLCache, cached
@@ -40,3 +40,8 @@ def create_order_in_db(self, customer_name: str, order_item_count: int) -> Order
 
         logger.info('finished create order', extra={'order_id': order_id, 'order_item_count': order_item_count, 'customer_name': customer_name})
         return entry
+
+
+@lru_cache
+def get_dal_handler(table_name: str) -> DalHandler:
+    return DynamoDalHandler(table_name)

service/dal/dynamo_dal_handler.py

@@ -1,18 +1,12 @@
-from functools import lru_cache
-
-from service.dal.dynamo_dal_handler import DynamoDalHandler
+from service.dal.db_handler import DalHandler
+from service.dal.dynamo_dal_handler import get_dal_handler
 from service.dal.schemas.db import OrderEntry
 from service.handlers.schemas.dynamic_configuration import FeatureFlagsNames
 from service.handlers.utils.dynamic_configuration import get_dynamic_configuration_store
 from service.handlers.utils.observability import logger, tracer
 from service.schemas.output import CreateOrderOutput
 
 
-@lru_cache
-def get_dynamodb_dal_handler(table_name: str) -> DynamoDalHandler:
-    return DynamoDalHandler(table_name)
-
-
 @tracer.capture_method(capture_response=False)
 def handle_create_request(customer_name: str, order_item_count: int, table_name: str) -> CreateOrderOutput:
     logger.info('starting to handle create request', extra={'order_item_count': order_item_count, 'customer_name': customer_name})
@@ -31,7 +25,7 @@ def handle_create_request(customer_name: str, order_item_count: int, table_name:
         default=False,
     )
     logger.debug('premium feature flag value', extra={'premium': premium})
-    dal_handler: DynamoDalHandler = get_dynamodb_dal_handler(table_name)
+    dal_handler: DalHandler = get_dal_handler(table_name)
     order: OrderEntry = dal_handler.create_order_in_db(customer_name, order_item_count)
     # convert from db entry to output, they won't always be the same
     return CreateOrderOutput(customer_name=order.customer_name, order_item_count=order.order_item_count, order_id=order.order_id)