Fix the month boundary calculation in monthly reports

Fixes: #497

CHANGELOG.md

@@ -17,6 +17,7 @@ All notable changes to this project will be documented in this file.
 - Fix sendalerts to clear Profile.next_nag_date if all checks up
 - Fix the pause action to clear Profile.next_nag_date if all checks up
 - Fix the "Email Reports" screen to clear Profile.next_nag_date if all checks up
+- Fix the month boundary calculation in monthly reports (#497)
 
 ## v1.19.0 - 2021-02-03
 

hc/accounts/models.py

@@ -195,6 +195,10 @@ class Profile(models.Model):
             "List-Unsubscribe-Post": "List-Unsubscribe=One-Click",
         }
 
+        boundaries = month_boundaries(months=3)
+        # throw away the current month, keep two previous months
+        boundaries.pop()
+
         ctx = {
             "checks": checks,
             "sort": self.sort,
@@ -204,7 +208,7 @@ class Profile(models.Model):
             "nag": nag,
             "nag_period": self.nag_period.total_seconds(),
             "num_down": num_down,
-            "month_boundaries": month_boundaries(),
+            "month_boundaries": boundaries,
         }
 
         emails.report(self.user.email, ctx, headers)

hc/accounts/tests/test_profile_model.py

@@ -1,12 +1,17 @@
-from datetime import timedelta as td
+from datetime import datetime, timedelta as td
+from unittest.mock import Mock, patch
 
 from django.core import mail
-from django.utils.timezone import now
+from django.utils.timezone import now, utc
 from hc.test import BaseTestCase
 from hc.api.models import Check
 
+CURRENT_TIME = datetime(2020, 1, 15, tzinfo=utc)
+MOCK_NOW = Mock(return_value=CURRENT_TIME)
+
 
 class ProfileModelTestCase(BaseTestCase):
+    @patch("hc.lib.date.timezone.now", MOCK_NOW)
     def test_it_sends_report(self):
         check = Check(project=self.project, name="Test Check")
         check.last_ping = now()
@@ -22,6 +27,12 @@ class ProfileModelTestCase(BaseTestCase):
         self.assertEqual(message.subject, "Monthly Report")
         self.assertIn("Test Check", message.body)
 
+        html, _ = message.alternatives[0]
+        self.assertNotIn("Jan. 2020", html)
+        self.assertIn("Dec. 2019", html)
+        self.assertIn("Nov. 2019", html)
+        self.assertNotIn("Oct. 2019", html)
+
     def test_it_skips_report_if_no_pings(self):
         check = Check(project=self.project, name="Test Check")
         check.save()