Fix filtering select widget options being empty on browser back

Author: mshibuya

spec/integration/widgets/filtering_select_spec.rb

@@ -99,6 +99,18 @@
     expect(all(:css, 'input.ra-filtering-select-input').count).to eq 1
   end
 
+  it 'does not lose options on browser back' do
+    visit edit_path(model_name: 'player', id: player.id)
+    find('.team_field .dropdown-toggle').click
+    find('li.ui-menu-item a', text: /Clear/).click
+    click_link 'Show'
+    is_expected.to have_content 'Details for Player'
+    page.go_back
+    find('.team_field input.ra-filtering-select-input').set('Los')
+    page.execute_script("document.querySelector('.team_field input.ra-filtering-select-input').dispatchEvent(new KeyboardEvent('keydown'))")
+    is_expected.to have_selector('ul.ui-autocomplete li.ui-menu-item a', text: 'Los Angeles Dodgers')
+  end
+
   context 'when using remote requests' do
     before do
       RailsAdmin.config Player do

src/rails_admin/filtering-select.js

@@ -216,11 +216,20 @@ import I18n from "./i18n";
         minLength: this.options.minLength,
         source: this._getSourceFunction(this.options.source),
         select: function (event, ui) {
-          var option = $("<option>")
-            .attr("value", ui.item.id)
-            .attr("selected", "selected")
-            .text(ui.item.value);
-          self.element.html(option).trigger("change", ui.item.id);
+          var option = self.element.find(
+            `option[value="${CSS.escape(ui.item.id)}"]`
+          );
+          self.element.find("option[selected]").attr("selected", false);
+          if (option.length > 0) {
+            option.attr("selected", "selected");
+          } else {
+            option = $("<option>")
+              .attr("value", ui.item.id)
+              .attr("selected", true)
+              .text(ui.item.value);
+            self.element.append(option);
+          }
+          self.element.trigger("change", ui.item.id);
           self._trigger("selected", event, {
             item: option,
           });