atom timestamps: fully convert to RFC 3339

for #126, #127

granary/atom.py

@@ -401,9 +401,13 @@ def _prepare_activity(a, reader=True):
   # make sure published and updated are strict RFC 3339 timestamps
   for prop in 'published', 'updated':
     val = obj.get(prop)
-    if val and '+' not in val and not val.endswith('Z'):
-      obj[prop] += 'Z'
-
+    if val:
+      obj[prop] = util.maybe_iso8601_to_rfc3339(val)
+      # Atom timestamps are even stricter than RFC 3339: they can't be naive ie
+      # time zone unaware. They must have either an offset or the Z suffix.
+      # https://www.feedvalidator.org/docs/error/InvalidRFC3339Date.html
+      if not util.TIMEZONE_OFFSET_RE.search(obj[prop]):
+        obj[prop] += 'Z'
 
 def _remove_query_params(url):
   parsed = list(urlparse.urlparse(url))

granary/test/test_atom.py

@@ -366,12 +366,15 @@ def test_render_missing_object_type_and_verb(self):
 
   def test_updated_defaults_to_published(self):
     activities = [
-      {'object': {'published': '2013-12-27T17:25:55+00:00'}},
-      {'object': {'published': '2014-12-27T17:25:55+00:00'}},
+      {'object': {'published': '2013-12-27T17:25:55+02:00'}},
+      {'object': {'published': '2014-12-27 17:25:55-0800'}},
+      {'object': {'published': '2015-12-27 17:25:55'}},
     ]
 
     out = atom.activities_to_atom(activities, test_twitter.ACTOR, title='my title')
-    self.assert_multiline_in('<updated>2014-12-27T17:25:55+00:00</updated>', out)
+    self.assert_multiline_in('<updated>2013-12-27T17:25:55+02:00</updated>', out)
+    self.assert_multiline_in('<updated>2014-12-27T17:25:55-08:00</updated>', out)
+    self.assert_multiline_in('<updated>2015-12-27T17:25:55Z</updated>', out)
 
   def test_escape_urls(self):
     url = 'http://foo/bar?baz&baj'