Do not pick up the placeholder as selection in filtering-multiselect. F…

…ixes #2807

app/assets/javascripts/rails_admin/ra.filtering-multiselect.js

@@ -118,7 +118,7 @@
 
       /* Add all to selection */
       this.addAll.click(function(e){
-        widget._select($('option', widget.collection));
+        widget._select($('option:not(:disabled)', widget.collection));
         e.preventDefault();
         widget.selection.trigger('change');
       });

spec/integration/widgets/filtering_multi_select_spec.rb

@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+describe 'FilteringMultiSelect widget', type: :request, js: true do
+  subject { page }
+
+  describe 'Choose all button' do
+    let(:team) { FactoryBot.create :team }
+    let!(:players) { FactoryBot.create_list :player, 2 }
+    before do
+      RailsAdmin.config Team do
+        field :players
+      end
+    end
+
+    it 'picks all available items' do
+      visit edit_path(model_name: 'team', id: team.id)
+      click_link 'Choose all'
+      expect(all(:css, '#team_player_ids option', visible: false).map(&:value)).to match_array players.map(&:id).map(&:to_s)
+    end
+
+    context 'when associated_collection_cache_all is false' do
+      before do
+        RailsAdmin.config Team do
+          field(:players) { associated_collection_cache_all false }
+        end
+      end
+
+      it "does not pick the placeholder for selection" do
+        visit edit_path(model_name: 'team', id: team.id)
+        click_link 'Choose all'
+        expect(page).not_to have_css('#team_player_ids option', visible: false)
+        expect(page).not_to have_css('.ra-multiselect-selection option')
+      end
+
+      it 'picks all available items' do
+        visit edit_path(model_name: 'team', id: team.id)
+        find('input.ra-multiselect-search').set('P')
+        page.execute_script("$('input.ra-multiselect-search').trigger('focus')")
+        page.execute_script("$('input.ra-multiselect-search').trigger('keydown')")
+        expect(page).to have_css('.ra-multiselect-collection option', text: /Player/)
+        click_link 'Choose all'
+        expect(all(:css, '#team_player_ids option', visible: false).map(&:value)).to match_array players.map(&:id).map(&:to_s)
+      end
+    end
+  end
+end