Create success notification and amend tabs behaviour with js controller

app/controllers/merge_requests_controller.rb

@@ -54,7 +54,8 @@ class MergeRequestsController < ApplicationController
 
   def delete
     @merge_request.discard!
-    redirect_to organisations_path(anchor: "merge-requests")
+    flash[:notice] = "The merge request has been deleted"
+    redirect_to organisations_path(tab: "merge-requests")
   end
 
   def merging_organisations

app/frontend/controllers/index.js

@@ -14,9 +14,13 @@ import GovukfrontendController from './govukfrontend_controller.js'
 import NumericQuestionController from './numeric_question_controller.js'
 
 import FilterLayoutController from './filter_layout_controller.js'
+
+import TabsController from './tabs_controller.js'
+
 application.register('accessible-autocomplete', AccessibleAutocompleteController)
 application.register('conditional-filter', ConditionalFilterController)
 application.register('conditional-question', ConditionalQuestionController)
 application.register('govukfrontend', GovukfrontendController)
 application.register('numeric-question', NumericQuestionController)
 application.register('filter-layout', FilterLayoutController)
+application.register('tabs', TabsController)

app/frontend/controllers/tabs_controller.js

@@ -0,0 +1,30 @@
+document.addEventListener("DOMContentLoaded", function() {
+  const urlParams = new URLSearchParams(window.location.search);
+  const tab = urlParams.get("tab");
+
+  function activateTab(tabId) {
+    const tabElement = document.getElementById(tabId);
+    if (tabElement) {
+      tabElement.click();
+    }
+    history.replaceState(null, null, `${window.location.pathname}?${urlParams.toString()}`);
+  }
+
+  function handleTabClick(event) {
+    event.preventDefault();
+    const targetId = this.getAttribute('href').substring(1);
+    activateTab(targetId);
+    urlParams.set("tab", targetId);
+    history.replaceState(null, null, `${window.location.pathname}?${urlParams.toString()}`);
+  }
+
+  if (tab) {
+    activateTab(`tab_${tab}`);
+  }
+
+  window.scrollTo(0, 0);
+
+  document.querySelectorAll('.govuk-tabs__tab').forEach(tabElement => {
+    tabElement.addEventListener('click', handleTabClick);
+  });
+});

app/helpers/merge_requests_helper.rb

@@ -59,7 +59,7 @@ module MergeRequestsHelper
 
     case page
     when "absorbing_organisation"
-      organisations_path(anchor: "merge-requests")
+      organisations_path(tab: "merge-requests")
     when "merging_organisations"
       absorbing_organisation_merge_request_path(merge_request)
     when "merge_date"

app/views/layouts/application.html.erb

@@ -126,7 +126,8 @@
           <%= govuk_notification_banner(
             title_text: "Success",
             success: true, title_heading_level: 3,
-            title_id: "flash-notice"
+            title_id: "flash-notice",
+            role: "alert",
           ) do |notification_banner|
             notification_banner.with_heading(text: flash.notice.html_safe)
             if flash[:notification_banner_body]

app/views/merge_requests/show.html.erb

@@ -1,7 +1,7 @@
 <% content_for :before_content do %>
   <% title = "Merge details: #{@merge_request.absorbing_organisation_name}" %>
   <% content_for :title, title %>
-  <%= govuk_back_link href: organisations_path(anchor: "merge-requests") %>
+  <%= govuk_back_link href: organisations_path(tab: "merge-requests") %>
 <% end %>
 
 <%= render partial: "notification_banners" %>

app/views/organisations/index.html.erb

@@ -5,7 +5,7 @@
 
 <%= render partial: "organisations/headings", locals: request.path == organisations_path ? { main: "Organisations", sub: nil } : { main: @organisation.name, sub: "Organisations" } %>
 
-<div class="app-tab__list-view">
+<div class="app-tab__list-view" data-controller="tabs">
   <%= govuk_tabs(title: "Collection resources", classes: %w[app-tab__large-headers]) do |c| %>
     <% c.with_tab(label: "All organisations") do %>
       <%= govuk_button_link_to "Create a new organisation", new_organisation_path, html: { method: :get } %>

spec/requests/merge_request_spec.rb

@@ -20,7 +20,7 @@ RSpec.describe MergeRequest, type: :request do
 
     it "redirects to the merge request list" do
       delete delete_merge_request_path(merge_request)
-      expect(response).to redirect_to(organisations_path(anchor: "merge-requests"))
+      expect(response).to redirect_to(organisations_path(tab: "merge-requests"))
       follow_redirect!
       expect(page).to have_content("Merge requests")
     end

spec/requests/merge_requests_controller_spec.rb

@@ -202,7 +202,7 @@ RSpec.describe MergeRequestsController, type: :request do
       end
 
       it "has the correct back button" do
-        expect(page).to have_link("Back", href: organisations_path(anchor: "merge-requests"))
+        expect(page).to have_link("Back", href: organisations_path(tab: "merge-requests"))
       end
     end