ngclient: Improve dosctrings and error messages

Signed-off-by: Jussi Kukkonen <[email protected]>

Author: Jussi Kukkonen

tuf/ngclient/_internal/trusted_metadata_set.py

@@ -353,8 +353,8 @@ def update_snapshot(self, data: bytes):  # pylint: disable=too-many-branches
             != self.timestamp.signed.meta["snapshot.json"].version
         ):
             raise exceptions.BadVersionNumberError(
-                f"Expected snapshot version"
-                f"{self.timestamp.signed.meta['snapshot.json'].version},"
+                f"Expected snapshot version "
+                f"{self.timestamp.signed.meta['snapshot.json'].version}, "
                 f"got {new_snapshot.signed.version}"
             )
 
@@ -373,8 +373,8 @@ def update_snapshot(self, data: bytes):  # pylint: disable=too-many-branches
                 # Prevent rollback of any metadata versions
                 if new_fileinfo.version < fileinfo.version:
                     raise exceptions.BadVersionNumberError(
-                        f"Expected {filename} version"
-                        f"{new_fileinfo.version}, got {fileinfo.version}"
+                        f"Expected {filename} version "
+                        f"{new_fileinfo.version}, got {fileinfo.version}."
                     )
 
         if new_snapshot.signed.is_expired(self.reference_time):
@@ -403,7 +403,7 @@ def update_delegated_targets(
         Args:
             data: unverified new metadata as bytes
             role_name: The role name of the new metadata
-            delegator_name: The name of the role delegating the new metadata
+            delegator_name: The name of the role delegating to the new metadata
 
         Raises:
             RepositoryError: Metadata failed to load or verify. The actual
@@ -452,8 +452,8 @@ def update_delegated_targets(
 
         if new_delegate.signed.version != meta.version:
             raise exceptions.BadVersionNumberError(
-                f"Expected {role_name} version"
-                f"{meta.version}, got {new_delegate.signed.version}"
+                f"Expected {role_name} version "
+                f"{meta.version}, got {new_delegate.signed.version}."
             )
 
         if new_delegate.signed.is_expired(self.reference_time):

tuf/ngclient/updater.py

@@ -32,7 +32,6 @@
 
 logger = logging.getLogger(__name__)
 
-# Classes
 class Updater:
     """
     An implemetation of the TUF client workflow.
@@ -79,7 +78,7 @@ def __init__(
     def refresh(self) -> None:
         """
         This method downloads, verifies, and loads metadata for the top-level
-        roles in a specific order (root -> timestamp -> snapshot -> targets)
+        roles in the specified order (root -> timestamp -> snapshot -> targets)
         The expiration time for downloaded metadata is also verified.
 
         The metadata for delegated roles are not refreshed by this method, but
@@ -104,8 +103,8 @@ def get_one_valid_targetinfo(self, target_path: str) -> Dict:
         """
         Returns the target information for a target identified by target_path.
 
-        As a side-effect this method downloads all the metadata it needs to
-        return the target information.
+        As a side-effect this method downloads all the additional (delegate
+        targets) metadata required to return the target information.
 
         Args:
             target_path: A target identifier that is a path-relative-URL string