shared_examples 'update invalid issuable' do |klass|
  let(:params) do
    {
      namespace_id: project.namespace.path,
      project_id: project.path,
      id: issuable.iid
    }
  end

  let(:issuable) do
    klass == Issue ? issue : merge_request
  end

  before do
    if klass == Issue
      params.merge!(issue: { title: "any" })
    else
      params.merge!(merge_request: { title: "any" })
    end
  end

  context 'when updating causes conflicts' do
    before do
      allow_any_instance_of(issuable.class).to receive(:save)
        .and_raise(ActiveRecord::StaleObjectError.new(issuable, :save))
    end

    if klass == MergeRequest
      it 'renders edit when format is html' do
        put :update, params

        expect(response).to render_template(:edit)
        expect(assigns[:conflict]).to be_truthy
      end
    end

    it 'renders json error message when format is json' do
      params[:format] = "json"

      put :update, params

      expect(response.status).to eq(409)
      expect(JSON.parse(response.body)).to have_key('errors')
    end
  end

  if klass == MergeRequest
    context 'when updating an invalid issuable' do
      before do
        params[:merge_request][:title] = ""
      end

      it 'renders edit when merge request is invalid' do
        put :update, params

        expect(response).to render_template(:edit)
      end
    end
  end
end