Add tests

spec/features/merge_requests/cherry_pick_spec.rb

+require 'spec_helper'
+
+describe 'Cherry-pick Merge Requests' do
+  let(:user) { create(:user) }
+  let(:project) { create(:project) }
+  let(:merge_request) { create(:merge_request_with_diffs, source_project: project, author: user) }
+
+  before do
+    login_as user
+    project.team << [user, :master]
+  end
+
+  context "Viewing a merged merge request" do
+    before do
+      service = MergeRequests::MergeService.new(project, user)
+
+      perform_enqueued_jobs do
+        service.execute(merge_request)
+      end
+    end
+
+    # Fast-forward merge, or merged before GitLab 8.5.
+    context "Without a merge commit" do
+      before do
+        merge_request.merge_commit_sha = nil
+        merge_request.save
+      end
+
+      it "doesn't show a Cherry-pick button" do
+        visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+
+        expect(page).not_to have_link "Cherry-pick"
+      end
+    end
+
+    context "With a merge commit" do
+      it "shows a Cherry-pick button" do
+        visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+
+        expect(page).to have_link "Cherry-pick"
+      end
+    end
+  end
+end