chore: use Git object to get commit

Signed-off-by: Ben Selwyn-Smith <benselwynsmith@googlemail.com>

src/macaron/repo_finder/repo_finder.py

@@ -107,7 +107,7 @@ def find_repo(purl: PackageURL, check_latest_version: bool = True) -> tuple[str,
         return found_repo, outcome
 
     # Try to find the latest version repo.
-    logger.error("Could not find repo for PURL: %s", purl)
+    logger.debug("Could not find repo for PURL: %s", purl)
     latest_version_purl = get_latest_purl_if_different(purl)
     if not latest_version_purl:
         logger.debug("Could not find newer PURL than provided: %s", purl)
@@ -217,13 +217,17 @@ def find_source(purl_string: str, input_repo: str | None, latest_version_fallbac
     # Disable other loggers for cleaner output.
     logging.getLogger("macaron.slsa_analyzer.analyzer").disabled = True
 
+    digest = ""
     if defaults.getboolean("repofinder", "find_source_should_clone"):
         # Clone the repo to retrieve the tags.
         logger.debug("Preparing repo: %s", found_repo)
         repo_dir = os.path.join(global_config.output_path, GIT_REPOS_DIR)
         logging.getLogger("macaron.slsa_analyzer.git_url").disabled = True
         # The prepare_repo function will also check the latest version of the artifact if required.
-        _, _, digest = prepare_repo(repo_dir, found_repo, purl=purl, latest_version_fallback=not checked_latest_purl)
+        git_obj, _ = prepare_repo(repo_dir, found_repo, purl=purl, latest_version_fallback=not checked_latest_purl)
+
+        if git_obj:
+            digest = git_obj.get_head().hash
 
         if not digest:
             return False
@@ -380,7 +384,7 @@ def prepare_repo(
     digest: str = "",
     purl: PackageURL | None = None,
     latest_version_fallback: bool = True,
-) -> tuple[Git | None, CommitFinderInfo, str]:
+) -> tuple[Git | None, CommitFinderInfo]:
     """Prepare the target repository for analysis.
 
     If ``repo_path`` is a remote path, the target repo is cloned to ``{target_dir}/{unique_path}``.
@@ -408,9 +412,8 @@ def prepare_repo(
 
     Returns
     -------
-    tuple[Git | None, CommitFinderInfo, str]
-            The pydriller.Git object of the repository or None if error; the outcome of the Commit Finder; and the final
-            digest.
+    tuple[Git | None, CommitFinderInfo]
+            The pydriller.Git object of the repository or None if error, and the outcome of the Commit Finder.
     """
     # TODO: separate the logic for handling remote and local repos instead of putting them into this method.
     logger.info(
@@ -428,7 +431,7 @@ def prepare_repo(
         resolved_remote_path = get_remote_vcs_url(repo_path)
         if not resolved_remote_path:
             logger.error("The provided path to repo %s is not a valid remote path.", repo_path)
-            return None, commit_finder_outcome, digest
+            return None, commit_finder_outcome
 
         git_service = get_git_service(resolved_remote_path)
         repo_unique_path = get_repo_dir_name(resolved_remote_path)
@@ -438,7 +441,7 @@ def prepare_repo(
             git_service.clone_repo(resolved_local_path, resolved_remote_path)
         except CloneError as error:
             logger.error("Cannot clone %s: %s", resolved_remote_path, str(error))
-            return None, commit_finder_outcome, digest
+            return None, commit_finder_outcome
     else:
         logger.info("Checking if the path to repo %s is a local path.", repo_path)
         resolved_local_path = resolve_local_path(get_local_repos_path(), repo_path)
@@ -448,29 +451,29 @@ def prepare_repo(
             git_obj = Git(resolved_local_path)
         except InvalidGitRepositoryError:
             logger.error("No git repo exists at %s.", resolved_local_path)
-            return None, commit_finder_outcome, digest
+            return None, commit_finder_outcome
     else:
         logger.error("Error happened while preparing the repo.")
-        return None, commit_finder_outcome, digest
+        return None, commit_finder_outcome
 
     if is_empty_repo(git_obj):
         logger.error("The target repository does not have any commit.")
-        return None, commit_finder_outcome, digest
+        return None, commit_finder_outcome
 
     # Find the digest if a version has been specified.
     if not digest and purl and purl.version:
         found_digest, commit_finder_outcome = find_commit(git_obj, purl)
         if not found_digest:
             logger.error("Could not map the input purl string to a specific commit in the corresponding repository.")
             if not latest_version_fallback:
-                return None, commit_finder_outcome, digest
+                return None, commit_finder_outcome
             # If the commit could not be found, check if the latest version of the artifact has a different repository.
             latest_purl = get_latest_purl_if_different(purl)
             if not latest_purl:
-                return None, commit_finder_outcome, digest
+                return None, commit_finder_outcome
             latest_repo = get_latest_repo_if_different(latest_purl, repo_path)
             if not latest_repo:
-                return None, commit_finder_outcome, digest
+                return None, commit_finder_outcome
             return prepare_repo(latest_repo, latest_repo, target_dir, latest_version_fallback=False)
 
         digest = found_digest
@@ -492,15 +495,15 @@ def prepare_repo(
             # ``git_url.check_out_repo_target``.
             if not check_out_repo_target(git_obj, branch_name, digest, not is_remote):
                 logger.error("Cannot checkout the specific branch or commit of the target repo.")
-                return None, commit_finder_outcome, digest
+                return None, commit_finder_outcome
 
-            return git_obj, commit_finder_outcome, digest
+            return git_obj, commit_finder_outcome
 
     try:
         git_service.check_out_repo(git_obj, branch_name, digest, not is_remote)
     except RepoCheckOutError as error:
         logger.error("Failed to check out repository at %s", resolved_local_path)
         logger.error(error)
-        return None, commit_finder_outcome, digest
+        return None, commit_finder_outcome
 
-    return git_obj, commit_finder_outcome, digest
+    return git_obj, commit_finder_outcome

src/macaron/slsa_analyzer/analyzer.py

@@ -382,13 +382,15 @@ def run_single(
         commit_finder_outcome = CommitFinderInfo.NOT_USED
         final_digest = analysis_target.digest
         if analysis_target.repo_path:
-            git_obj, commit_finder_outcome, final_digest = prepare_repo(
+            git_obj, commit_finder_outcome = prepare_repo(
                 os.path.join(self.output_path, GIT_REPOS_DIR),
                 analysis_target.repo_path,
                 analysis_target.branch,
                 analysis_target.digest,
                 analysis_target.parsed_purl,
             )
+            if git_obj:
+                final_digest = git_obj.get_head().hash
 
         repo_finder_metadata = RepoFinderMetadata(
             repo_finder_outcome=analysis_target.repo_finder_outcome,