Enrich commits with full data in CommitCollection

Allow incomplete commit records to load their full data from gitaly.

Commits can be based on a Hash of data retrieved from PostgreSQL, and
this data can be intentionally incomplete in order to save space.

A new method #gitaly? has been added to Gitlab::Git::Commit, which
returns true if the underlying data source of the Commit is a
Gitaly::GitCommit.

CommitCollection now has a method #enrich which replaces non-gitaly
commits in place with commits from gitaly.

CommitCollection#without_merge_commits has been updated to call this
method, as in order to determine a merge commit we need to have parent
data.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/58805

1 files changed, 14 insertions, 19 deletions

diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index 42c49e330cc..c487ae45ceb 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -84,32 +84,27 @@ describe MergeRequest do
 
   describe '#default_squash_commit_message' do
     let(:project) { subject.project }
-
-    def commit_collection(commit_hashes)
-      raw_commits = commit_hashes.map { |raw| Commit.from_hash(raw, project) }
-
-      CommitCollection.new(project, raw_commits)
-    end
+    let(:is_multiline) { -> (c) { c.description.present? } }
+    let(:multiline_commits) { subject.commits.select(&is_multiline) }
+    let(:singleline_commits) { subject.commits.reject(&is_multiline) }
 
     it 'returns the oldest multiline commit message' do
-      commits = commit_collection([
-        { message: 'Singleline', parent_ids: [] },
-        { message: "Second multiline\nCommit message", parent_ids: [] },
-        { message: "First multiline\nCommit message", parent_ids: [] }
-      ])
-
-      expect(subject).to receive(:commits).and_return(commits)
-
-      expect(subject.default_squash_commit_message).to eq("First multiline\nCommit message")
+      expect(subject.default_squash_commit_message).to eq(multiline_commits.last.message)
     end
 
     it 'returns the merge request title if there are no multiline commits' do
-      commits = commit_collection([
-        { message: 'Singleline', parent_ids: [] }
-      ])
+      expect(subject).to receive(:commits).and_return(
+        CommitCollection.new(project, singleline_commits)
+      )
+
+      expect(subject.default_squash_commit_message).to eq(subject.title)
+    end
 
-      expect(subject).to receive(:commits).and_return(commits)
+    it 'does not return commit messages from multiline merge commits' do
+      collection = CommitCollection.new(project, multiline_commits).enrich!
 
+      expect(collection.commits).to all( receive(:merge_commit?).and_return(true) )
+      expect(subject).to receive(:commits).and_return(collection)
       expect(subject.default_squash_commit_message).to eq(subject.title)
     end
   end