Replaced magic time constants with understandable constant names

Previous calculation of "seconds per year" assumed 365 days á 24 * 60 *
60 seconds, while we actually want 12 months á 31 days á 24 * 60 * 60
seconds

Author: MarkusH

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 5.2.0 (under development)
 
-* ...
+* Added constants outlining expiration and duration time bases for purchases
 
 ## 5.1.0
 

laterpay/__init__.py

@@ -19,7 +19,7 @@
 import six
 from six.moves.urllib.parse import quote_plus
 
-from . import signing, utils
+from . import constants, signing, utils
 
 
 _logger = logging.getLogger(__name__)
@@ -89,12 +89,17 @@ def __init__(self, item_id, pricing, url, title, expiry=None, sub_id=None, perio
                     "uppercase ASCII characters, digits, underscore and hyphen, the length of "
                     "which is between 1 and 128 characters." % sub_id
                 )
-            if isinstance(period, int) and 3600 <= period <= 31536000:
+            if (
+                isinstance(period, int) and
+                constants.EXPIRY_SECONDS_FOR_HOUR <= period <= constants.EXPIRY_SECONDS_FOR_YEAR
+            ):
                 self.data['period'] = period
             else:
                 raise InvalidItemDefinition(
                     "Period not set or invalid value '%s' for period. The subscription period "
-                    "must be an int in the range [3600, 31536000] (including)." % period
+                    "must be an int in the range [%d, %d] (including)." % (
+                        period, constants.EXPIRY_SECONDS_FOR_HOUR, constants.EXPIRY_SECONDS_FOR_YEAR,
+                    )
                 )
 
 

laterpay/constants.py

@@ -0,0 +1,13 @@
+EXPIRY_SECONDS_FOR_HOUR = 60 * 60
+EXPIRY_SECONDS_FOR_DAY = 60 * 60 * 24
+EXPIRY_SECONDS_FOR_WEEK = 60 * 60 * 24 * 7
+EXPIRY_SECONDS_FOR_MONTH = 60 * 60 * 24 * 31
+EXPIRY_SECONDS_FOR_YEAR = 60 * 60 * 24 * 31 * 12
+
+EXPIRY_SECONDS_FOR_TIME_UNITS = {
+    'h': EXPIRY_SECONDS_FOR_HOUR,
+    'd': EXPIRY_SECONDS_FOR_DAY,
+    'w': EXPIRY_SECONDS_FOR_WEEK,
+    'm': EXPIRY_SECONDS_FOR_MONTH,
+    'y': EXPIRY_SECONDS_FOR_YEAR,
+}

tests/test_client.py

@@ -37,9 +37,9 @@ def test_invalid_sub_id(self):
 
     def test_invalid_period(self):
         with self.assertRaisesRegexp(InvalidItemDefinition, r'Period not set or invalid value'):
-            ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=3599)
+            ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=60 * 60 - 1)
         with self.assertRaisesRegexp(InvalidItemDefinition, r'Period not set or invalid value'):
-            ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=31536001)
+            ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=60 * 60 * 24 * 31 * 12 + 1)
         with self.assertRaisesRegexp(InvalidItemDefinition, r'Period not set or invalid value'):
             ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period='12345')
 
@@ -55,8 +55,8 @@ def test_item_definition(self):
 
     def test_sub_id(self):
         # Test sub_id_bounds
-        ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=3600)
-        ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a' * 128, period=31536000)
+        ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a', period=60 * 60)
+        ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='a' * 128, period=60 * 60 * 24 * 31 * 12)
 
         it = ItemDefinition(1, 'EUR20', 'http://example.com/t', 'title', sub_id='abc', period=12345)
         self.assertEqual(it.data, {