Migration to add international letter rates

New rows giving the prices of letters with a post_class of `europe` and
`rest-of-world` have been added to the `letter_rates` table. All rates
are currently the same for international letters.

tests/app/celery/test_reporting_tasks.py

@@ -243,6 +243,22 @@ def test_create_nightly_billing_for_day_different_letter_postage(
         billable_units=2,
         postage='second'
     )
+    create_notification(
+        created_at=yesterday,
+        template=sample_letter_template,
+        status='delivered',
+        sent_by='dvla',
+        billable_units=1,
+        postage='europe'
+    )
+    create_notification(
+        created_at=yesterday,
+        template=sample_letter_template,
+        status='delivered',
+        sent_by='dvla',
+        billable_units=3,
+        postage='rest-of-world'
+    )
 
     records = FactBilling.query.all()
     assert len(records) == 0
@@ -251,18 +267,31 @@ def test_create_nightly_billing_for_day_different_letter_postage(
     create_nightly_billing_for_day(yesterday_str)
 
     records = FactBilling.query.order_by('postage').all()
-    assert len(records) == 2
+    assert len(records) == 4
+
     assert records[0].notification_type == LETTER_TYPE
     assert records[0].bst_date == datetime.date(yesterday)
-    assert records[0].postage == 'first'
-    assert records[0].notifications_sent == 2
-    assert records[0].billable_units == 4
+    assert records[0].postage == 'europe'
+    assert records[0].notifications_sent == 1
+    assert records[0].billable_units == 1
 
     assert records[1].notification_type == LETTER_TYPE
     assert records[1].bst_date == datetime.date(yesterday)
-    assert records[1].postage == 'second'
-    assert records[1].notifications_sent == 1
-    assert records[1].billable_units == 2
+    assert records[1].postage == 'first'
+    assert records[1].notifications_sent == 2
+    assert records[1].billable_units == 4
+
+    assert records[2].notification_type == LETTER_TYPE
+    assert records[2].bst_date == datetime.date(yesterday)
+    assert records[2].postage == 'rest-of-world'
+    assert records[2].notifications_sent == 1
+    assert records[2].billable_units == 3
+
+    assert records[3].notification_type == LETTER_TYPE
+    assert records[3].bst_date == datetime.date(yesterday)
+    assert records[3].postage == 'second'
+    assert records[3].notifications_sent == 1
+    assert records[3].billable_units == 2
 
 
 def test_create_nightly_billing_for_day_letter(

tests/app/dao/test_ft_billing_dao.py

@@ -326,10 +326,12 @@ def test_get_rates_for_billing(notify_db_session):
     create_rate(start_date=datetime.utcnow(), value=33, notification_type='email')
     create_letter_rate(start_date=datetime.utcnow(), rate=0.66, post_class='first')
     create_letter_rate(start_date=datetime.utcnow(), rate=0.33, post_class='second')
+    create_letter_rate(start_date=datetime.utcnow(), rate=0.84, post_class='europe')
+    create_letter_rate(start_date=datetime.utcnow(), rate=0.84, post_class='rest-of-world')
     non_letter_rates, letter_rates = get_rates_for_billing()
 
     assert len(non_letter_rates) == 3
-    assert len(letter_rates) == 2
+    assert len(letter_rates) == 4
 
 
 @freeze_time('2017-06-01 12:00')
@@ -353,10 +355,17 @@ def test_get_rate(notify_db_session):
     assert letter_rate == Decimal('0.3')
 
 
-@pytest.mark.parametrize("letter_post_class,expected_rate", [("first", "0.61"), ("second", "0.35")])
+@pytest.mark.parametrize("letter_post_class,expected_rate", [
+    ("first", "0.61"),
+    ("second", "0.35"),
+    ("europe", "0.92"),
+    ("rest-of-world", "1.05"),
+])
 def test_get_rate_filters_letters_by_post_class(notify_db_session, letter_post_class, expected_rate):
     create_letter_rate(start_date=datetime(2017, 5, 30, 23, 0), sheet_count=2, rate=0.61, post_class='first')
     create_letter_rate(start_date=datetime(2017, 5, 30, 23, 0), sheet_count=2, rate=0.35, post_class='second')
+    create_letter_rate(start_date=datetime(2017, 5, 30, 23, 0), sheet_count=2, rate=0.92, post_class='europe')
+    create_letter_rate(start_date=datetime(2017, 5, 30, 23, 0), sheet_count=2, rate=1.05, post_class='rest-of-world')
 
     non_letter_rates, letter_rates = get_rates_for_billing()
     rate = get_rate(non_letter_rates, letter_rates, "letter", datetime(2018, 10, 1), True, 2, letter_post_class)