Use naive datetimes for format_delta math

app/formatters.py

@@ -9,7 +9,6 @@ from numbers import Number
 import ago
 import dateutil
 import humanize
-import pytz
 from flask import Markup, current_app, url_for
 from notifications_utils.field import Field
 from notifications_utils.formatters import make_quotes_smart
@@ -166,11 +165,12 @@ def naturaltime_without_indefinite_article(date):
 
 
 def format_delta(date):
+    # This method assumes that date is in UTC
     date = parse_naive_dt(date)
     delta = (
-        datetime.now(timezone.utc)
+        datetime.utcnow()
     ) - (
-        convert_utc_to_local_timezone(date).replace(tzinfo=pytz.utc)
+        date
     )
     if delta < timedelta(seconds=30):
         return "just now"
@@ -180,9 +180,9 @@ def format_delta(date):
 
 
 def format_delta_days(date):
+    # This method assumes that date is in UTC
     date = parse_naive_dt(date)
-    now = datetime.now(timezone.utc)
-    date = convert_utc_to_local_timezone(date).replace(tzinfo=pytz.utc)
+    now = datetime.utcnow()
     if date.strftime('%Y-%m-%d') == now.strftime('%Y-%m-%d'):
         return "today"
     if date.strftime('%Y-%m-%d') == (now - timedelta(days=1)).strftime('%Y-%m-%d'):

tests/app/main/test_formatters.py

@@ -1,3 +1,4 @@
+from datetime import datetime
 from functools import partial
 
 import pytest
@@ -7,6 +8,7 @@ from freezegun import freeze_time
 from app.formatters import (
     email_safe,
     format_datetime_relative,
+    format_delta,
     format_notification_status_as_url,
     format_number_in_pounds_as_currency,
     round_to_significant_figures,
@@ -129,3 +131,8 @@ def test_round_to_significant_figures(value, significant_figures, expected_resul
 ])
 def test_email_safe_return_dot_separated_email_domain(service_name, safe_email):
     assert email_safe(service_name) == safe_email
+
+
+def test_format_delta():
+    naive_now_utc = datetime.utcnow().isoformat()
+    assert format_delta(naive_now_utc) == "just now"

tests/app/main/views/test_dashboard.py

@@ -230,7 +230,7 @@ def test_inbound_messages_shows_count_of_messages_when_there_are_messages(
     banner = page.select('a.banner-dashboard')[1]
     assert normalize_spaces(
         banner.text
-    ) == '9,999 text messages received latest message 5 hours ago'
+    ) == '9,999 text messages received latest message just now'
     assert banner['href'] == url_for(
         'main.inbox', service_id=SERVICE_ONE_ID
     )
@@ -264,14 +264,14 @@ def test_inbound_messages_shows_count_of_messages_when_there_are_no_messages(
 
 
 @pytest.mark.parametrize('index, expected_row', enumerate([
-    '07900 900000 message-1 6 hours ago',
-    '07900 900000 message-2 6 hours ago',
-    '07900 900000 message-3 6 hours ago',
-    '07900 900002 message-4 8 hours ago',
-    '+33 1 12 34 56 78 message-5 10 hours ago',
-    '+1 202-555-0104 message-6 12 hours ago',
-    '+1 202-555-0104 message-7 14 hours ago',
-    '+682 12345 message-8 14 hours ago',
+    '07900 900000 message-1 1 hour ago',
+    '07900 900000 message-2 1 hour ago',
+    '07900 900000 message-3 1 hour ago',
+    '07900 900002 message-4 3 hours ago',
+    '+33 1 12 34 56 78 message-5 5 hours ago',
+    '+1 202-555-0104 message-6 7 hours ago',
+    '+1 202-555-0104 message-7 9 hours ago',
+    '+682 12345 message-8 9 hours ago',
 ]))
 def test_inbox_showing_inbound_messages(
     client_request,

tests/app/main/views/test_find_users.py

@@ -121,7 +121,7 @@ def test_user_information_page_shows_information_about_user(
         'test@gsa.gov',
         '+447700900986',
         'Text message code',
-        'Last logged in 5 hours ago',
+        'Last logged in just now',
     ]
 
     assert '0 failed login attempts' not in page.text

tests/app/main/views/test_templates.py

@@ -1867,7 +1867,7 @@ def test_should_show_delete_template_page_with_time_block(
     mocker.patch('app.template_statistics_client.get_last_used_date_for_template',
                  return_value='2012-01-01 12:00:00')
 
-    with freeze_time('2012-01-01 7:10:00'):
+    with freeze_time('2012-01-01 12:10:00'):
         page = client_request.get(
             '.delete_service_template',
             service_id=SERVICE_ONE_ID,