Bitbucket Server importer: Eliminate most idle-in-transaction issues

Just like with the GitHub importer, the Bitbucket Server importer can hit the
default 60 s idle-in-transaction timeouts if it takes too long to create the
merge request. We solve this by using the same approach as the GitHub importer:

1. Bypass all validation and hooks in creating a merge request
2. Insert the Git data in a separate transaction

Part of #50021

1 files changed, 43 insertions, 0 deletions

diff --git a/spec/lib/gitlab/import/merge_request_creator_spec.rb b/spec/lib/gitlab/import/merge_request_creator_spec.rb
new file mode 100644
index 00000000000..cd3359da341
--- /dev/null
+++ b/spec/lib/gitlab/import/merge_request_creator_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Import::MergeRequestCreator do
+  let(:project) { create(:project, :repository) }
+
+  subject { described_class.new(project) }
+
+  describe '#execute' do
+    context 'merge request already exists' do
+      let(:merge_request) { create(:merge_request, target_project: project, source_project: project) }
+      let(:commits) { merge_request.merge_request_diffs.first.commits }
+      let(:attributes) { HashWithIndifferentAccess.new(merge_request.attributes) }
+
+      it 'updates the data' do
+        commits_count = commits.count
+        merge_request.merge_request_diffs.destroy_all # rubocop: disable DestroyAll
+
+        expect(merge_request.merge_request_diffs.count).to eq(0)
+
+        subject.execute(attributes)
+
+        expect(merge_request.reload.merge_request_diffs.count).to eq(1)
+        expect(merge_request.reload.merge_request_diffs.first.commits.count).to eq(commits_count)
+      end
+    end
+
+    context 'new merge request' do
+      let(:merge_request) { build(:merge_request, target_project: project, source_project: project) }
+      let(:attributes) { HashWithIndifferentAccess.new(merge_request.attributes) }
+
+      it 'creates a new merge request' do
+        attributes.delete(:id)
+
+        expect { subject.execute(attributes) }.to change { MergeRequest.count }.by(1)
+
+        new_mr = MergeRequest.last
+        expect(new_mr.merge_request_diffs.count).to eq(1)
+      end
+    end
+  end
+end