Add endpoint for fetching diverging commit countsid-stale-branches

Extract diverging_commit_counts into a service class

1 files changed, 52 insertions, 0 deletions

diff --git a/spec/services/branches/diverging_commit_counts_service_spec.rb b/spec/services/branches/diverging_commit_counts_service_spec.rb
new file mode 100644
index 00000000000..bfdbebdb7c1
--- /dev/null
+++ b/spec/services/branches/diverging_commit_counts_service_spec.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Branches::DivergingCommitCountsService do
+  let(:project) { create(:project, :repository) }
+  let(:repository) { project.repository }
+
+  describe '#call' do
+    let(:diverged_branch) { repository.find_branch('fix') }
+    let(:root_ref_sha) { repository.raw_repository.commit(repository.root_ref).id }
+    let(:diverged_branch_sha) { diverged_branch.dereferenced_target.sha }
+
+    let(:service) { described_class.new(repository) }
+
+    it 'returns the commit counts behind and ahead of default branch' do
+      result = service.call(diverged_branch)
+
+      expect(result).to eq(behind: 29, ahead: 2)
+    end
+
+    context 'when gitaly_count_diverging_commits_no_max is enabled' do
+      before do
+        stub_feature_flags(gitaly_count_diverging_commits_no_max: true)
+      end
+
+      it 'calls diverging_commit_count without max count' do
+        expect(repository.raw_repository)
+          .to receive(:diverging_commit_count)
+          .with(root_ref_sha, diverged_branch_sha)
+          .and_return([29, 2])
+
+        service.call(diverged_branch)
+      end
+    end
+
+    context 'when gitaly_count_diverging_commits_no_max is disabled' do
+      before do
+        stub_feature_flags(gitaly_count_diverging_commits_no_max: false)
+      end
+
+      it 'calls diverging_commit_count with max count' do
+        expect(repository.raw_repository)
+          .to receive(:diverging_commit_count)
+          .with(root_ref_sha, diverged_branch_sha, max_count: Repository::MAX_DIVERGING_COUNT)
+          .and_return([29, 2])
+
+        service.call(diverged_branch)
+      end
+    end
+  end
+end