Update turbo views to update partial

app/views/events/_registration_section.html.erb

@@ -0,0 +1,30 @@
+<% registered = event.event_registrations.exists?(registrant_id: current_user&.id) %>
+<%= tag.div id: dom_id(event.object, :registration_section), class: "registration-section flex flex-col gap-4 mb-6" do %>
+  <!-- ⭐ BUTTONS -->
+  <div class="flex flex-wrap items-center gap-3">
+    <% if registered %>
+      <%= button_to "De-register",
+                    event_registrant_registration_path(event_id: event),
+                    method: :delete,
+                    data: { turbo_confirm: "Are you sure?" },
+                    class: "btn btn-secondary-outline" %>
+    <% elsif event.registerable? %>
+      <%= button_to "Register",
+                    event_registrant_registration_path(event_id: event),
+                    class: "btn btn-primary-outline" %>
+    <% else %>
+      <span class="text-sm text-gray-500 italic">Registration closed</span>
+    <% end %>
+
+    <% if registered %>
+      <span class="text-xs bg-green-100 text-green-700 px-2 py-0.5 rounded-full">
+        You are registered!
+      </span>
+    <% end %>
+  </div>
+
+  <!-- ⭐ CALENDAR LINKS -->
+  <% if registered %>
+    <div class="flex gap-2 items-center text-sm text-gray-700"><%= event.calendar_links %></div>
+  <% end %>
+<% end %>

app/views/events/registrations/create.turbo_stream.erb

@@ -1,2 +1,3 @@
-<%= turbo_stream.replace dom_id(@event, :card), partial: "events/card", locals: {event: @event} %>
+<%= turbo_stream.replace dom_id(@event, :card), partial: "events/card", locals: { event: @event } %>
+<%= turbo_stream.replace dom_id(@event, :registration_section), partial: "events/registration_section", locals: { event: @event.decorate } %>
 <%= turbo_stream.replace "flash_now", partial: "shared/flash_messages" %>

app/views/events/registrations/destroy.turbo_stream.erb

@@ -1,2 +1,3 @@
-<%= turbo_stream.replace dom_id(@event, :card), partial: "events/card", locals: {event: @event} %>
+<%= turbo_stream.replace dom_id(@event, :card), partial: "events/card", locals: { event: @event } %>
+<%= turbo_stream.replace dom_id(@event, :registration_section), partial: "events/registration_section", locals: { event: @event.decorate } %>
 <%= turbo_stream.replace "flash_now", partial: "shared/flash_messages" %>

app/views/events/show.html.erb

@@ -34,38 +34,7 @@
                 <div><%= @event.labelled_cost %></div>
               <% end %>
 
-              <div class="registration-section flex flex-col gap-4 mb-6">
-                <!-- ⭐ BUTTONS -->
-                <div class="flex flex-wrap items-center gap-3">
-                  <% registered = @event.event_registrations.exists?(registrant_id: current_user&.id) %>
-
-                  <% if registered %>
-                    <%= button_to "De-register",
-                    event_registrant_registration_path(event_id: @event),
-                    method: :delete,
-                    data: {
-                      turbo_confirm: "Are you sure?",
-                    },
-                    class: "btn btn-secondary-outline" %>
-                  <% elsif @event.registerable? %>
-                    <%= button_to "Register",
-                    event_registrant_registration_path(event_id: @event),
-                    class: "btn btn-primary-outline" %>
-                  <% else %>
-                    <span class="text-sm text-gray-500 italic">Registration closed</span>
-                  <% end %>
-
-                  <% if registered %>
-                    <span class="text-xs bg-green-100 text-green-700 px-2 py-0.5 rounded-full">
-                      You are registered!
-                    </span>
-                  <% end %>
-                </div>
-                <!-- ⭐ CALENDAR LINKS -->
-                <% if registered %>
-                  <div class="flex gap-2 items-center text-sm text-gray-700"><%= @event.calendar_links %></div>
-                <% end %>
-              </div>
+              <%= render "events/registration_section", event: @event %>
 
               <% if @event.registration_close_date %>
                 <div>

spec/system/events_show_spec.rb

@@ -130,6 +130,47 @@
     end
   end
 
+  # --------------------------------------------------
+  # REGISTRATION BUTTON UPDATES VIA TURBO
+  # --------------------------------------------------
+
+  describe "registration button updates via Turbo", js: true do
+    before { driven_by(:selenium_chrome_headless) }
+
+    it "updates Register to De-register and shows badge without full page reload" do
+      sign_in(user)
+      visit event_path(event)
+
+      expect(page).to have_button("Register")
+      expect(page).not_to have_text("You are registered!")
+
+      click_button "Register"
+
+      # Turbo stream replaces the registration section; we stay on the event page
+      expect(page).to have_current_path(event_path(event))
+      expect(page).to have_button("De-register")
+      expect(page).to have_text("You are registered!")
+      expect(page).not_to have_button("Register")
+    end
+
+    it "updates De-register back to Register after de-registering" do
+      create(:event_registration, event: event, registrant: user)
+
+      sign_in(user)
+      visit event_path(event)
+
+      expect(page).to have_button("De-register")
+      accept_confirm do
+        click_button "De-register"
+      end
+
+      expect(page).to have_current_path(event_path(event))
+      expect(page).to have_button("Register")
+      expect(page).not_to have_button("De-register")
+      expect(page).not_to have_text("You are registered!")
+    end
+  end
+
   # --------------------------------------------------
   # REGISTRATION CLOSE DATE SECTION
   # --------------------------------------------------