Fixes next() and previous() hanging when passed an invalid input

Author: sdispater

pendulum/date.py

@@ -848,6 +848,9 @@ def next(self, day_of_week=None):
         if day_of_week is None:
             day_of_week = self.day_of_week
 
+        if day_of_week < SUNDAY or day_of_week > SATURDAY:
+            raise ValueError('Invalid day of week')
+
         dt = self.add(days=1)
         while dt.day_of_week != day_of_week:
             dt = dt.add(days=1)
@@ -869,6 +872,9 @@ def previous(self, day_of_week=None):
         if day_of_week is None:
             day_of_week = self.day_of_week
 
+        if day_of_week < SUNDAY or day_of_week > SATURDAY:
+            raise ValueError('Invalid day of week')
+
         dt = self.subtract(days=1)
         while dt.day_of_week != day_of_week:
             dt = dt.subtract(days=1)

pendulum/pendulum.py

@@ -17,7 +17,8 @@
     YEARS_PER_CENTURY, YEARS_PER_DECADE,
     MONTHS_PER_YEAR,
     MINUTES_PER_HOUR, SECONDS_PER_MINUTE,
-    SECONDS_PER_DAY
+    SECONDS_PER_DAY,
+    SUNDAY, SATURDAY
 )
 
 
@@ -1434,6 +1435,9 @@ def next(self, day_of_week=None, keep_time=False):
         if day_of_week is None:
             day_of_week = self.day_of_week
 
+        if day_of_week < SUNDAY or day_of_week > SATURDAY:
+            raise ValueError('Invalid day of week')
+
         if keep_time:
             dt = self
         else:
@@ -1463,6 +1467,9 @@ def previous(self, day_of_week=None, keep_time=False):
         if day_of_week is None:
             day_of_week = self.day_of_week
 
+        if day_of_week < SUNDAY or day_of_week > SATURDAY:
+            raise ValueError('Invalid day of week')
+
         if keep_time:
             dt = self
         else:

tests/date_tests/test_day_of_week_modifiers.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+import pytest
+
 import pendulum
 from pendulum import Date
 from pendulum.exceptions import PendulumException
@@ -67,6 +69,12 @@ def test_next_saturday(self):
         d = Date(1975, 5, 21).next(6)
         self.assertDate(d, 1975, 5, 24)
 
+    def test_next_invalid(self):
+        dt = pendulum.date(1975, 5, 21)
+
+        with pytest.raises(ValueError):
+            dt.next(7)
+
     def test_previous(self):
         d = Date(1975, 5, 21).previous()
         self.assertDate(d, 1975, 5, 14)
@@ -79,6 +87,12 @@ def test_previous_saturday(self):
         d = Date(1975, 5, 21).previous(6)
         self.assertDate(d, 1975, 5, 17)
 
+    def test_previous_invalid(self):
+        dt = pendulum.date(1975, 5, 21)
+
+        with pytest.raises(ValueError):
+            dt.previous(7)
+
     def test_first_day_of_month(self):
         d = Date(1975, 11, 21).first_of('month', )
         self.assertDate(d, 1975, 11, 1)

tests/pendulum_tests/test_day_of_week_modifiers.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+import pytest
+
 import pendulum
 from pendulum import Pendulum
 from pendulum.exceptions import PendulumException
@@ -83,6 +85,12 @@ def test_next_keep_time(self):
         d = Pendulum.create(1975, 5, 21, 12).next(keep_time=True)
         self.assertPendulum(d, 1975, 5, 28, 12, 0, 0)
 
+    def test_next_invalid(self):
+        dt = pendulum.create(1975, 5, 21, 12)
+
+        with pytest.raises(ValueError):
+            dt.next(7)
+
     def test_previous(self):
         d = Pendulum.create(1975, 5, 21).previous()
         self.assertPendulum(d, 1975, 5, 14, 0, 0, 0)
@@ -102,6 +110,12 @@ def test_previous_keep_time(self):
         d = Pendulum.create(1975, 5, 21, 12).previous(keep_time=True)
         self.assertPendulum(d, 1975, 5, 14, 12, 0, 0)
 
+    def test_previous_invalid(self):
+        dt = pendulum.create(1975, 5, 21, 12)
+
+        with pytest.raises(ValueError):
+            dt.previous(7)
+
     def test_first_day_of_month(self):
         d = Pendulum.create(1975, 11, 21).first_of('month', )
         self.assertPendulum(d, 1975, 11, 1, 0, 0, 0)