Fix Russia calendar: non-working days shifted to MON when they happen…

… on the week-end

refs #589

Changelog.md

@@ -2,7 +2,7 @@
 
 ## master (unreleased)
 
-Nothing here yet.
+- Fix Russia calendar: non-working days are shifted to the next MON when they happen on the week-end (#589).
 
 ## v13.0.0 (2020-11-13)
 

workalendar/europe/russia.py

@@ -1,11 +1,10 @@
-from ..core import OrthodoxCalendar
+from ..core import OrthodoxCalendar, MON
 from ..registry_tools import iso_register
 
 
 @iso_register('RU')
 class Russia(OrthodoxCalendar):
     'Russia'
-
     shift_new_years_day = True
 
     # Civil holidays
@@ -20,3 +19,15 @@ class Russia(OrthodoxCalendar):
         (6, 12, "National Day"),
         (11, 4, "Day of Unity"),
     )
+
+    def get_calendar_holidays(self, year):
+        holidays = super().get_calendar_holidays(year)
+        shifts = []
+        for day, label in holidays:
+            if day.weekday() in self.get_weekend_days():
+                shifts.append((
+                    self.get_first_weekday_after(day, MON),
+                    label + " shift"
+                ))
+        holidays.extend(shifts)
+        return holidays

workalendar/tests/test_europe.py

@@ -1410,6 +1410,33 @@ def test_year_2018(self):
         self.assertIn(date(2018, 6, 12), holidays)  # National Day
         self.assertIn(date(2018, 11, 4), holidays)  # Independence Day
 
+    def test_year_2020_shift(self):
+        holidays = dict(self.cal.holidays(2020))
+        # Defender of the Fatherland Day
+        self.assertIn(date(2020, 2, 23), holidays)
+        # SUN => Shift to MON
+        self.assertIn(date(2020, 2, 24), holidays)
+        self.assertEqual(
+            holidays[date(2020, 2, 24)],
+            "Defendence of the Fatherland shift"
+        )
+        # International Women's Day
+        self.assertIn(date(2020, 3, 8), holidays)
+        # SUN => Shift to MON
+        self.assertIn(date(2020, 3, 9), holidays)
+        self.assertEqual(
+            holidays[date(2020, 3, 9)],
+            "International Women's Day shift"
+        )
+        # Victory Day
+        self.assertIn(date(2020, 5, 9), holidays)
+        # SAT => Shift to MON
+        self.assertIn(date(2020, 5, 11), holidays)
+        self.assertEqual(
+            holidays[date(2020, 5, 11)],
+            "Victory Day shift"
+        )
+
 
 class UkraineTest(GenericCalendarTest):
     cal_class = Ukraine