Add test-letters bucket for precompiled test keys

- uses moto to mock out boto3 for testing

app/letters/utils.py

@@ -5,13 +5,14 @@ from flask import current_app
 
 from notifications_utils.s3 import s3upload
 
+from app.models import KEY_TYPE_TEST
 from app.variables import Retention
 
 
 LETTERS_PDF_FILE_LOCATION_STRUCTURE = \
     '{folder}NOTIFY.{reference}.{duplex}.{letter_class}.{colour}.{crown}.{date}.pdf'
 
-PRECOMPILED_BUCKET_PREFIX = '{folder}/NOTIFY.{reference}'
+PRECOMPILED_BUCKET_PREFIX = '{folder}NOTIFY.{reference}'
 
 
 def get_folder_name(_now, is_test_letter):
@@ -41,9 +42,10 @@ def get_letter_pdf_filename(reference, crown, is_test_letter=False):
     return upload_file_name
 
 
-def get_bucket_prefix_for_notification(notification):
+def get_bucket_prefix_for_notification(notification, is_test_letter=False):
     upload_file_name = PRECOMPILED_BUCKET_PREFIX.format(
-        folder=notification.created_at.date(),
+        folder='' if is_test_letter else
+               '{}/'.format(notification.created_at.date()),
         reference=notification.reference
     ).upper()
 
@@ -75,12 +77,16 @@ def upload_letter_pdf(notification, pdf_data, is_test_letter=False):
 
 
 def get_letter_pdf(notification):
-    bucket_name = current_app.config['LETTERS_PDF_BUCKET_NAME']
+    is_test_letter = notification.key_type == KEY_TYPE_TEST and notification.template.is_precompiled_letter
+    if is_test_letter:
+        bucket_name = current_app.config['TEST_LETTERS_BUCKET_NAME']
+    else:
+        bucket_name = current_app.config['LETTERS_PDF_BUCKET_NAME']
 
     s3 = boto3.resource('s3')
     bucket = s3.Bucket(bucket_name)
 
-    for item in bucket.objects.filter(Prefix=get_bucket_prefix_for_notification(notification)):
+    for item in bucket.objects.filter(Prefix=get_bucket_prefix_for_notification(notification, is_test_letter)):
         obj = s3.Object(
             bucket_name=bucket_name,
             key=item.key