feat: replace Member.all with TomSelect in meeting invitations

- Replace Chosen.js dropdown with TomSelect for member lookup
- Load members dynamically via /admin/members/search endpoint
- Add select_from_tom_select helper for Capybara tests
- Update tests for remote data loading
- Exclude #meeting_invitations_member from Chosen.js initialization

Reuses /admin/members/search endpoint from PR #2562.
Fixes performance issue loading 28k+ members on every page render.

Author: mroderick

app/assets/javascripts/application.js

@@ -70,13 +70,42 @@ $(function() {
     });
   }
 
-  // Chosen for all other selects (exclude #member_lookup_id)
+  // TomSelect for meeting invitation member lookup
+  if ($('#meeting_invitations_member').length) {
+    new TomSelect('#meeting_invitations_member', {
+      placeholder: 'Type to search members...',
+      valueField: 'id',
+      labelField: 'full_name',
+      searchField: ['full_name', 'email'],
+      create: false,
+      loadThrottle: 300,
+      shouldLoad: function(query) {
+        return query.length >= 3;
+      },
+      load: function(query, callback) {
+        fetch('/admin/members/search?q=' + encodeURIComponent(query))
+          .then(response => response.json())
+          .then(json => callback(json))
+          .catch(() => callback());
+      },
+      render: {
+        option: function(item, escape) {
+          return '<div>' + escape(item.full_name) + ' <small class="text-muted">' + escape(item.email) + '</small></div>';
+        },
+        no_results: function(data, escape) {
+          return '<div class="no-results">No members found</div>';
+        }
+      }
+    });
+  }
+
+  // Chosen for all other selects (exclude TomSelect fields)
   // Chosen hides inputs and selects, which becomes problematic when they are
   // required: browser validation doesn't get shown to the user.
   // This fix places "the original input behind the Chosen input, matching the
   // height and width so that the warning appears in the correct position."
   // https://github.com/harvesthq/chosen/issues/515#issuecomment-474588057
-  $('select').not('#member_lookup_id').on('chosen:ready', function () {
+  $('select').not('#member_lookup_id, #meeting_invitations_member').on('chosen:ready', function () {
     var height = $(this).next('.chosen-container').height();
     var width = $(this).next('.chosen-container').width();
 
@@ -88,7 +117,7 @@ $(function() {
     }).show();
   });
 
-  $('select').not('#member_lookup_id').chosen({
+  $('select').not('#member_lookup_id, #meeting_invitations_member').chosen({
     allow_single_deselect: true,
     no_results_text: 'No results matched'
   });

app/views/admin/meetings/_invitation_management.html.haml

@@ -3,15 +3,13 @@
     .card.bg-white.border-success
       .card-body
         %p.mb-0
-          <strong>#{@invitations.count}</strong> members have RSVP'd to this event.
+          %strong #{@invitations.count}
+          members have RSVP'd to this event.
 
 = simple_form_for :meeting_invitations, url: admin_meeting_invitations_path do |f|
   .row
     .col-6
-      = f.select :member,
-                  Member.all.map { |u| ["#{u.full_name}", u.id] },
-                  { include_blank: true }, { class: 'chosen-select', required: true,
-                  data: { placeholder: t('messages.invitations.select_a_member_to_rsvp') } }
+      = f.select :member, [], { include_blank: true }, { class: 'tom-select', required: true, data: { placeholder: t('messages.invitations.select_a_member_to_rsvp') } }
       = f.hidden_field :meeting_id, value: @meeting.slug
     .col
       = f.button :button, 'Add', class: 'btn btn-sm btn-primary mb-0 me-2'

app/views/admin/meetings/show.html.haml

@@ -54,6 +54,9 @@
       = sanitize(@meeting.description)
 
 - if @invitations.any?
+  - content_for :head do
+    %link{ href: 'https://cdn.jsdelivr.net/npm/tom-select@2.4.3/dist/css/tom-select.bootstrap5.min.css', rel: 'stylesheet', type: 'text/css' }
+    %script{ src: 'https://cdn.jsdelivr.net/npm/tom-select@2.4.3/dist/js/tom-select.complete.min.js' }
   .py-4.py-lg-5.bg-light
     .container#invitations
       = render partial: 'invitation_management'

spec/features/admin/managing_meeting_invitations_spec.rb

@@ -8,25 +8,27 @@
   end
 
   describe 'creating a new meeting invitation' do
-    scenario 'for a member that is not already attending' do
+    scenario 'for a member that is not already attending', :js do
       Fabricate(:attending_meeting_invitation, meeting: meeting)
       member = Fabricate(:member)
 
       visit admin_meeting_path(meeting)
-      select member.name
+
+      select_from_tom_select(member.full_name, from: 'meeting_invitations_member')
       click_on 'Add'
 
       expect(page).to have_content("#{member.full_name} has been successfully added and notified via email")
     end
 
-    scenario 'for a member that is already attending' do
+    scenario 'for a member that is already attending', :js do
       meeting = Fabricate(:meeting)
       attending_member = Fabricate(:member)
       Fabricate(:attending_meeting_invitation, meeting: meeting)
       Fabricate(:attending_meeting_invitation, meeting: meeting, member: attending_member)
 
       visit admin_meeting_path(meeting)
-      select attending_member.name
+
+      select_from_tom_select(attending_member.full_name, from: 'meeting_invitations_member')
       click_on 'Add'
 
       expect(page).to have_content("#{attending_member.full_name} is already on the list!")
@@ -35,11 +37,9 @@
 
   scenario 'Updating the attendance of an invitation' do
     meeting = Fabricate(:meeting, date_and_time: 1.day.ago)
-    member = Fabricate(:member)
     Fabricate(:attending_meeting_invitation, meeting: meeting)
 
     visit admin_meeting_path(meeting)
-
     find('.verify-attendance').click
 
     expect(page).to have_content('Updated attendance')

spec/support/select_from_tom_select.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Helper for interacting with TomSelect dropdowns in Capybara feature tests
+# Similar to select_from_chosen but for TomSelect remote data loading
+module SelectFromTomSelect
+  # Select an item from a TomSelect dropdown
+  # @param item_text [String] The text to select
+  # @param from [String, Symbol] The field ID (for documentation purposes)
+  def select_from_tom_select(item_text, from: nil)
+    # Wait for TomSelect to initialize
+    expect(page).to have_css('.ts-wrapper', wait: 5)
+
+    # Open dropdown and type search query
+    find('.ts-control').click
+    input = find('.ts-control input')
+
+    # Type first 3 characters to trigger search (shouldLoad requires >= 3)
+    input.send_keys(item_text[0, 3])
+
+    # Wait for debounce (300ms) and network request
+    sleep 0.5
+
+    # Type the rest if item_text is longer than 3 characters
+    input.send_keys(item_text[3..]) if item_text.length > 3
+
+    # Wait for results (includes debounce + network)
+    expect(page).to have_css('.ts-dropdown .option', wait: 5)
+
+    # Click the matching option
+    find('.ts-dropdown .option', text: item_text, match: :prefer_exact).click
+  end
+end
+
+RSpec.configure do |config|
+  config.include SelectFromTomSelect, type: :feature
+end