Pass current_user to merge_request.closes_issues in API ans streamline MR API specs

lib/api/merge_requests.rb

@@ -310,7 +310,7 @@ module API
         #   GET /projects/:id/merge_requests/:merge_request_id/closes_issues
         get "#{path}/closes_issues" do
           merge_request = user_project.merge_requests.find(params[:merge_request_id])
-          issues = ::Kaminari.paginate_array(merge_request.closes_issues)
+          issues = ::Kaminari.paginate_array(merge_request.closes_issues(current_user))
           present paginate(issues), with: Entities::Issue
         end
       end

spec/factories/merge_requests.rb

@@ -73,12 +73,6 @@ FactoryGirl.define do
       merge_user author
     end
-    trait :with_closes_issues do
-      source_branch "markdown"
-      target_branch "master"
-      state :opened
-    end
-
     factory :closed_merge_request, traits: [:closed]
     factory :reopened_merge_request, traits: [:reopened]
     factory :merge_request_with_diffs, traits: [:with_diffs]

spec/requests/api/merge_requests_spec.rb

@@ -448,25 +448,21 @@ describe API::API, api: true  do
     end
   end
-  describe "GET :id/merge_requests/:merge_request_id/closes_issues" do
-    let(:merge_request_with_closes_issues) { create(:merge_request, :with_closes_issues, author: user, assignee: user, source_project: project, target_project: project, title: "Closed ##{issue.id}", created_at: base_time + 3.seconds, description: "This should close ##{issue.iid}") }
-    let(:issue) do
-      create :issue,
-        author: user,
-        assignee: user,
-        project: project,
-        milestone: nil
-    end
-    it "should return the issues that will be closed on merge" do
-      get api("/projects/#{project.id}/merge_requests/#{merge_request_with_closes_issues.id}/closes_issues", user)
+  describe 'GET :id/merge_requests/:merge_request_id/closes_issues' do
+    it 'returns the issue that will be closed on merge' do
+      issue = create(:issue, project: project)
+      mr = merge_request.tap do |mr|
+        mr.update_attribute(:description, "Closes #{issue.to_reference(mr.project)}")
+      end
+      get api("/projects/#{project.id}/merge_requests/#{mr.id}/closes_issues", user)
       expect(response.status).to eq(200)
       expect(json_response).to be_an Array
       expect(json_response.length).to eq(1)
       expect(json_response.first['id']).to eq(issue.id)
     end
-    it "should return an empty array when there are no issues to be closed" do
+    it 'returns an empty array when there are no issues to be closed' do
       get api("/projects/#{project.id}/merge_requests/#{merge_request.id}/closes_issues", user)
       expect(response.status).to eq(200)
       expect(json_response).to be_an Array