master:

add test for patch update from previously patched archive

tests/test_client.py

@@ -1,3 +1,5 @@
+import filecmp
+import gzip
 import logging
 import os
 import pathlib
@@ -208,6 +210,40 @@ def test_check_for_updates_failed_patch(self):
  self.assertTrue(target_meta.is_archive)
  self.assertIn('aborting', ''.join(logs.output))
 
+ def test_check_for_updates_after_patch(self):
+ """
+ Our patching process ensures that the reconstructed uncompressed .tar archive
+ is identical to the uncompressed original. However, the gzip compressed
+ archives are likely to be different (gzip output is not guaranteed to be
+ identical, between implementations, even for identical input). This means the
+ hash of a *reconstructed* .tar.gz file most likely does not match the hash of
+ the original .tar.gz file (as found in the tuf metadata). This test verifies
+ that the tuf target hash mismatch does not impede the patch update process.
+ """
+ client = self.get_refreshed_client()
+ # copy current compressed archive for reference
+ original_gz = client.current_archive_local_path.with_name('original.tar.gz')
+ shutil.copy(src=client.current_archive_local_path, dst=original_gz)
+ # decompress and recompress archive, as if it were reconstructed from patch
+ with gzip.open(original_gz, 'rb') as src:
+ with gzip.open(client.current_archive_local_path, 'wb') as dst:
+ dst.write(src.read())
+ # verify that the two .tar.gz files are indeed different (even though the
+ # uncompressed .tar content is identical)
+ self.assertFalse(
+ filecmp.cmp(original_gz, client.current_archive_local_path, shallow=False)
+ )
+ # test: even though the .tar.gz hash does not match the one in the tuf
+ # metadata, a patch update should be scheduled
+ with patch.object(client, 'refresh', Mock()):
+ archive_meta = client.check_for_updates()
+ # check_for_updates always returns *archive* meta (or None), even if the
+ # actual update is a *patch*
+ self.assertTrue(archive_meta)
+ # verify that the update is a *patch*
+ target_meta = next(iter(client.new_targets.keys()))
+ self.assertTrue(target_meta.is_patch)
+
  def test__download_updates(self):
  client = Client(**self.client_kwargs)
  client.new_targets = {Mock(): Mock()}