Avoid full clones when already at the tip of a branch

dependabot · Nov 4, 2022 · 95c6f95 · 95c6f95
1 parent 389ae99
commit 95c6f95
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Showing 3 changed files with 24 additions and 8 deletions.
diff --git a/common/lib/dependabot/git_commit_checker.rb b/common/lib/dependabot/git_commit_checker.rb
@@ -70,6 +70,11 @@ def pinned_ref_looks_like_commit_sha?
       ref_looks_like_commit_sha?(ref)
     end
 
+    def head_commit_for_pinned_ref
+      ref = dependency_source_details.fetch(:ref)
+      local_repo_git_metadata_fetcher.head_commit_for_ref_sha(ref)
+    end
+
     def ref_looks_like_commit_sha?(ref)
       return false unless ref&.match?(/^[0-9a-f]{6,40}$/)
 

diff --git a/common/lib/dependabot/git_metadata_fetcher.rb b/common/lib/dependabot/git_metadata_fetcher.rb
@@ -44,6 +44,12 @@ def head_commit_for_ref(ref)
         commit_sha
     end
 
+    def head_commit_for_ref_sha(ref)
+      refs_for_upload_pack.
+        find { |r| r.ref_sha == ref }&.
+        commit_sha
+    end
+
     private
 
     attr_reader :url, :credentials

diff --git a/github_actions/lib/dependabot/github_actions/update_checker.rb b/github_actions/lib/dependabot/github_actions/update_checker.rb
@@ -84,18 +84,23 @@ def fetch_latest_version_for_git_dependency
 
       def latest_commit_for_pinned_ref
         @latest_commit_for_pinned_ref ||= begin
-          url = dependency_source_details[:url]
-          source = Source.from_url(url)
+          head_commit_for_ref_sha = git_commit_checker.head_commit_for_pinned_ref
+          if head_commit_for_ref_sha
+            head_commit_for_ref_sha
+          else
+            url = dependency_source_details[:url]
+            source = Source.from_url(url)
 
-          SharedHelpers.in_a_temporary_directory(File.dirname(source.repo)) do |temp_dir|
-            repo_contents_path = File.join(temp_dir, File.basename(source.repo))
+            SharedHelpers.in_a_temporary_directory(File.dirname(source.repo)) do |temp_dir|
+              repo_contents_path = File.join(temp_dir, File.basename(source.repo))
 
-            SharedHelpers.run_shell_command("git clone --no-recurse-submodules #{url} #{repo_contents_path}")
+              SharedHelpers.run_shell_command("git clone --no-recurse-submodules #{url} #{repo_contents_path}")
 
-            Dir.chdir(repo_contents_path) do
-              ref_branch = find_container_branch(dependency_source_details[:ref])
+              Dir.chdir(repo_contents_path) do
+                ref_branch = find_container_branch(dependency_source_details[:ref])
 
-              git_commit_checker.head_commit_for_local_branch(ref_branch)
+                git_commit_checker.head_commit_for_local_branch(ref_branch)
+              end
             end
           end
         end