[IMPR] move to assertRaisesRegex

Bug: T154281
Change-Id: I837ba0d511814d8ae4c247f548ed9421ee869066
---
M tests/pagegenerators_tests.py
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tests/pagegenerators_tests.py b/tests/pagegenerators_tests.py
index 09a6d26..51bbd7a 100755
--- a/tests/pagegenerators_tests.py
+++ b/tests/pagegenerators_tests.py
@@ -548,14 +548,16 @@
 
     def test_start_0(self):
         """Test for day page generator with startMonth 0."""
-        with self.assertRaises(
-                calendar.IllegalMonthError):
+        with self.assertRaisesRegex(
+                calendar.IllegalMonthError,
+                'bad month number 0; must be 1-12'):
             self._run_test(0)
 
     def test_end_13(self):
         """Test for day page generator with endMonth 13."""
-        with self.assertRaises(
-                calendar.IllegalMonthError):
+        with self.assertRaisesRegex(
+                calendar.IllegalMonthError,
+                'bad month number 13; must be 1-12'):
             self._run_test(12, 13)
 
 

