Ignore invalid pre-release specifiers when checking for updates (#121)

* add test to reproduce issue120

* ignore invalid pre-release specifiers (fixes #120)

src/tufup/client.py

@@ -153,7 +153,11 @@ def check_for_updates(
 
  If `patch` is `False`, a full update is enforced.
  """
- included = {None: '', '': '', 'a': 'abrc', 'b': 'brc', 'rc': 'rc'}
+ # invalid pre-release specifiers are ignored, with a warning
+ pre_map = dict(a='abrc', b='brc', rc='rc')
+ prereleases = pre_map.get(pre, '')
+ if pre and not prereleases:
+ logger.warning(f'ignoring invalid pre-release specifier: "{pre}"')
  # refresh top-level metadata (root -> timestamp -> snapshot -> targets)
  try:
  self.refresh()
@@ -177,7 +181,7 @@ def check_for_updates(
  item
  for item in all_new_targets.items()
  if item[0].is_archive
- and (not item[0].version.pre or item[0].version.pre[0] in included[pre])
+ and (not item[0].version.pre or item[0].version.pre[0] in prereleases)
  )
  new_archive_meta = None
  if new_archives:

tests/test_client.py

@@ -150,16 +150,18 @@ def test_download_and_apply_update(self):
 
  def test_check_for_updates(self):
  # expectations (based on targets in tests/data/repository):
- # - pre=None: only full releases are included, so finds 2.0 patch
+ # - pre=None, '', or 'invalid': only full releases are included, finds 2.0 patch
  # - pre='a': finds all, but total patch size exceeds archive size
  # - pre='b': there is no 'b' release, so this finds same as 'rc'
  # - pre='rc': finds 2.0 and 3.0rc0, total patch size smaller than archive
  client = self.get_refreshed_client()
  with patch.object(client, 'refresh', Mock()):
- for pre, expected in [(None, 1), ('a', 1), ('b', 2), ('rc', 2)]:
+ for pre, expected in [
+ (None, 1), ('', 1), ('a', 1), ('b', 2), ('rc', 2), ('invalid', 1)
+ ]:
  with self.subTest(msg=pre):
  target_meta = client.check_for_updates(pre=pre)
- self.assertTrue(target_meta)
+ self.assertTrue(expected and target_meta)
  self.assertEqual(expected, len(client.new_targets))
  if pre == 'a':
  self.assertTrue(