Upgrade to govuk frontend 5.1.0

Gemfile.lock

@@ -189,7 +189,7 @@ GEM
     govuk_personalisation (0.16.0)
       plek (>= 1.9.0)
       rails (>= 6, < 8)
-    govuk_publishing_components (39.2.5)
+    govuk_publishing_components (40.0.0)
       govuk_app_config
       govuk_personalisation (>= 0.7.0)
       kramdown

app/assets/config/manifest.js

@@ -1,6 +1,7 @@
 //= link_tree ../images
 //= link application.js
 //= link test-dependencies.js
+//= link es6-components.js
 //= link live_search.js
 
-//= link_tree ../builds
+//= link_tree ../builds

app/assets/javascripts/analytics-ga4/ga4-finder-tracker.js

@@ -1,4 +1,4 @@
-//= require govuk/vendor/polyfills/Element/prototype/closest.js
+//= require govuk_publishing_components/vendor/polyfills-govuk-frontend-v4/Element/prototype/closest.js
 ;(function (global) {
   'use strict'
 

app/assets/javascripts/application.js

@@ -10,13 +10,10 @@
 // Read Sprockets README (https://github.com/sstephenson/sprockets#sprockets-directives) for details
 // about supported directives.
 //= require govuk_publishing_components/lib
-//= require govuk_publishing_components/components/checkboxes
-//= require govuk_publishing_components/components/error-summary
 //= require govuk_publishing_components/components/govspeak
 //= require govuk_publishing_components/components/intervention
 //= require govuk_publishing_components/components/metadata
 //= require govuk_publishing_components/components/option-select
-//= require govuk_publishing_components/components/radio
 //= require govuk_publishing_components/analytics/explicit-cross-domain-links
 //
 //= require support

app/assets/javascripts/es6-components.js

@@ -0,0 +1,12 @@
+// These modules from govuk_publishing_components
+// depend on govuk-frontend modules. govuk-frontend
+// now targets browsers that support `type="module"`.
+//
+// To gracefully prevent execution of these scripts
+// on browsers that don't support ES6, this script
+// should be included in a `type="module"` script tag
+// which will ensure they are never loaded.
+
+//= require govuk_publishing_components/components/checkboxes
+//= require govuk_publishing_components/components/error-summary
+//= require govuk_publishing_components/components/radio

app/assets/stylesheets/application.scss

@@ -1,8 +1,3 @@
-$govuk-compatibility-govuktemplate: false;
-$govuk-use-legacy-palette: false;
-$govuk-new-link-styles: true;
-$govuk-use-legacy-font: false;
-
 // This flag stops the font from being included in this application's
 // stylesheet - the font is being served by Static across all of GOV.UK, so is
 // not needed here.

app/views/layouts/development_layout.html.erb

@@ -16,6 +16,7 @@
       render_component_stylesheets
     %>
     <%= javascript_include_tag "application", integrity: false %>
+    <%= javascript_include_tag 'es6-components', integrity: false, type: "module" %>
     <meta name="robots" content="noindex">
   </head>
 

app/views/layouts/finder_layout.html.erb

@@ -17,6 +17,7 @@
     %>
     <%= javascript_include_tag 'test-dependencies.js' if Rails.env.test? %>
     <%= javascript_include_tag 'application', integrity: false %>
+    <%= javascript_include_tag 'es6-components', integrity: false, type: "module" %>
     <%= csrf_meta_tags %>
     <%= yield :head %>
 

app/views/layouts/search_layout.html.erb

@@ -7,6 +7,7 @@
     <title><%= yield :title %> - GOV.UK</title>
     <link title="Search" rel="search" type="application/opensearchdescription+xml" href="/search/opensearch.xml"/>
     <%= stylesheet_link_tag "application", media: "all", integrity: false %>
+    <%= javascript_include_tag 'es6-components', integrity: false, type: "module" %>
     <%=
       render_component_stylesheets
     %>