fixes 'Cannot set property '_renderItem' of undefined' when adding a nested resource

[tmesquita]

Fixes #2722

[mshibuya]

Spec is failing, can you take a look?

[tmesquita]

I'm looking into, it looks like it fails when using Capybara >=2.10.0. I haven't used Capybara much so it's taking me a little while trying to figure out what in that update is causing the test to no longer pass.

FWIW I'm also seeing the same thing happening on the master branch

[tmesquita]

I think the test that is failing is a bum test

From what I can tell, the block for have_selector was not getting run prior to Capybara v2.1.0 which was released about a week ago (2016-10-05) since that functionality wasn't implemented until that version (teamcapybara/capybara@b5655e9#diff-5b48908a3d2bd3374aaef7b6394f1912R39)

# https://github.com/sferik/rails_admin/blob/master/spec/integration/basic/edit/rails_admin_basic_edit_spec.rb#L76
describe 'edit with has-and-belongs-to-many association' do
    before do
      @teams = FactoryGirl.create_list(:team, 3)
      @fan = FactoryGirl.create :fan, teams: [@teams[0]]
      visit edit_path(model_name: 'fan', id: @fan.id)
    end

    it 'shows associated objects' do      
      is_expected.to have_selector '#fan_team_ids' do |select|         
        # This block doesn't seem to run prior to Capybara v2.1.0
        expect(select[0]).to have_selector 'option[selected="selected"]'
        expect(select[1]).not_to have_selector 'option[selected="selected"]'
        expect(select[2]).not_to have_selector 'option[selected="selected"]'
      end
    end
end

[benhutton]

@tmesquita thank you! 👍

[kubudubu]

When can we expect integration with master? ;)

[mshibuya]

Awesome, thanks!