Metadata API: Remove 3 'update' methods + tests

Remove ambiguous, unspecific, opinionated and trivial 'update'
methods, which can be replaced by feasible one-liners that assign
values directly to the object attribute to be *updated*. (see #1627
for details).

Reasons to have these methods would be increased usability in terms of
- reduced work
- immediate feedback on invalid assignments

However, given above described issues, the reasons against the
methods as they are now seem to outweigh the reasons for them.
Furthermore, it seems easier to re-add similar methods, which
addressed these issues, after the upcoming 1.0.0 release than to
remove or modify them.

This patch also removes the corresponding tests as they become
irrelevant (there is no need to test object assignment).  In the
case of the timestamp test, the removal also includes redundant
test logic, which is already tested in `test_metadata_base`.

Signed-off-by: Lukas Puehringer <[email protected]>

Author: lukpueh

tests/test_api.py

@@ -32,7 +32,6 @@
     Delegations,
     Key,
     Metadata,
-    MetaFile,
     Root,
     Snapshot,
     TargetFile,
@@ -297,56 +296,6 @@ def test_metadata_base(self) -> None:
         with self.assertRaises(ValueError):
             Metadata.from_dict(data)
 
-    def test_metadata_snapshot(self) -> None:
-        snapshot_path = os.path.join(self.repo_dir, "metadata", "snapshot.json")
-        snapshot = Metadata[Snapshot].from_file(snapshot_path)
-
-        # Create a MetaFile instance representing what we expect
-        # the updated data to be.
-        hashes = {
-            "sha256": "c2986576f5fdfd43944e2b19e775453b96748ec4fe2638a6d2f32f1310967095"
-        }
-        fileinfo = MetaFile(2, 123, hashes)
-
-        self.assertNotEqual(
-            snapshot.signed.meta["role1.json"].to_dict(), fileinfo.to_dict()
-        )
-        snapshot.signed.update("role1", fileinfo)
-        self.assertEqual(
-            snapshot.signed.meta["role1.json"].to_dict(), fileinfo.to_dict()
-        )
-
-    def test_metadata_timestamp(self) -> None:
-        timestamp_path = os.path.join(
-            self.repo_dir, "metadata", "timestamp.json"
-        )
-        timestamp = Metadata[Timestamp].from_file(timestamp_path)
-
-        self.assertEqual(timestamp.signed.version, 1)
-        timestamp.signed.bump_version()
-        self.assertEqual(timestamp.signed.version, 2)
-
-        self.assertEqual(timestamp.signed.expires, datetime(2030, 1, 1, 0, 0))
-        timestamp.signed.bump_expiration()
-        self.assertEqual(timestamp.signed.expires, datetime(2030, 1, 2, 0, 0))
-        timestamp.signed.bump_expiration(timedelta(days=365))
-        self.assertEqual(timestamp.signed.expires, datetime(2031, 1, 2, 0, 0))
-
-        # Create a MetaFile instance representing what we expect
-        # the updated data to be.
-        hashes = {
-            "sha256": "0ae9664468150a9aa1e7f11feecb32341658eb84292851367fea2da88e8a58dc"
-        }
-        fileinfo = MetaFile(2, 520, hashes)
-
-        self.assertNotEqual(
-            timestamp.signed.snapshot_meta.to_dict(), fileinfo.to_dict()
-        )
-        timestamp.signed.update(fileinfo)
-        self.assertEqual(
-            timestamp.signed.snapshot_meta.to_dict(), fileinfo.to_dict()
-        )
-
     def test_metadata_verify_delegate(self) -> None:
         root_path = os.path.join(self.repo_dir, "metadata", "root.json")
         root = Metadata[Root].from_file(root_path)
@@ -505,30 +454,6 @@ def test_is_target_in_pathpattern(self) -> None:
                 DelegatedRole._is_target_in_pathpattern(targetpath, pathpattern)
             )
 
-    def test_metadata_targets(self) -> None:
-        targets_path = os.path.join(self.repo_dir, "metadata", "targets.json")
-        targets = Metadata[Targets].from_file(targets_path)
-
-        # Create a fileinfo dict representing the expected updated data.
-        filename = "file2.txt"
-        hashes = {
-            "sha256": "141f740f53781d1ca54b8a50af22cbf74e44c21a998fa2a8a05aaac2c002886b",
-            "sha512": "ef5beafa16041bcdd2937140afebd485296cd54f7348ecd5a4d035c09759608de467a7ac0eb58753d0242df873c305e8bffad2454aa48f44480f15efae1cacd0",
-        }
-
-        fileinfo = TargetFile(length=28, hashes=hashes, path=filename)
-
-        # Assert that data is not aleady equal
-        self.assertNotEqual(
-            targets.signed.targets[filename].to_dict(), fileinfo.to_dict()
-        )
-        # Update an already existing fileinfo
-        targets.signed.update(fileinfo)
-        # Verify that data is updated
-        self.assertEqual(
-            targets.signed.targets[filename].to_dict(), fileinfo.to_dict()
-        )
-
     def test_targets_key_api(self) -> None:
         targets_path = os.path.join(self.repo_dir, "metadata", "targets.json")
         targets: Targets = Metadata[Targets].from_file(targets_path).signed

tuf/api/metadata.py

@@ -993,11 +993,6 @@ def to_dict(self) -> Dict[str, Any]:
         res_dict["meta"] = {"snapshot.json": self.snapshot_meta.to_dict()}
         return res_dict
 
-    # Modification.
-    def update(self, snapshot_meta: MetaFile) -> None:
-        """Assigns passed info about snapshot metadata."""
-        self.snapshot_meta = snapshot_meta
-
 
 class Snapshot(Signed):
     """A container for the signed part of snapshot metadata.
@@ -1049,12 +1044,6 @@ def to_dict(self) -> Dict[str, Any]:
         snapshot_dict["meta"] = meta_dict
         return snapshot_dict
 
-    # Modification.
-    def update(self, rolename: str, role_info: MetaFile) -> None:
-        """Assigns passed (delegated) targets role info to meta dict."""
-        metadata_fn = f"{rolename}.json"
-        self.meta[metadata_fn] = role_info
-
 
 class DelegatedRole(Role):
     """A container with information about a delegated role.
@@ -1463,11 +1452,6 @@ def to_dict(self) -> Dict[str, Any]:
             targets_dict["delegations"] = self.delegations.to_dict()
         return targets_dict
 
-    # Modification.
-    def update(self, fileinfo: TargetFile) -> None:
-        """Assigns passed target file info to meta dict."""
-        self.targets[fileinfo.path] = fileinfo
-
     def add_key(self, role: str, key: Key) -> None:
         """Adds new signing key for delegated role 'role'.