Disable Search Autocomplete based off env var presence

Autocomplete uses a denylist to stop certain terms from serving
suggestions. The process to update the denylist is very manual and
developer heavy.

It might be difficult to update the denylist over the holiday period. In
that situation the decision might be taken to temporarily turn off
autocomplete entirely.

An environment variable is used to determine whether or not to render
search with autocomplete. The value of this variable will be applied
globally across all applications that use site search.

See: alphagov/govuk-helm-charts#2832

Co-authored-by: Leena Gupte <leena.gupte@digital.cabinet-office.gov.uk>

Gemfile.lock

@@ -105,6 +105,7 @@ GEM
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
     chartkick (5.1.2)
+    climate_control (1.2.0)
     coderay (1.1.3)
     concurrent-ruby (1.3.4)
     connection_pool (2.4.1)
@@ -614,6 +615,7 @@ PLATFORMS
 
 DEPENDENCIES
   capybara
+  climate_control
   dartsass-rails
   faker
   gds-api-adapters

app/views/govuk_publishing_components/components/_layout_super_navigation_header.html.erb

@@ -317,7 +317,7 @@
                   label: "Site-wide",
                 }
               ) do %>
-                <%= render "govuk_publishing_components/components/search_with_autocomplete", {
+                <% search_options = {
                   name: "keywords",
                   inline_label: false,
                   label_size: "m",
@@ -326,9 +326,15 @@
                   size: "large",
                   margin_bottom: 0,
                   disable_corrections: true,
-                  source_url: [Plek.new.website_root, "/api/search/autocomplete.json"].join,
-                  source_key: "suggestions"
                 } %>
+                <% if ENV["GOVUK_DISABLE_SEARCH_AUTOCOMPLETE"] %>
+                  <%= render "govuk_publishing_components/components/search", search_options %>
+                <% else %>
+                  <%= render "govuk_publishing_components/components/search_with_autocomplete", search_options.merge({
+                    source_url: [Plek.new.website_root, "/api/search/autocomplete.json"].join,
+                    source_key: "suggestions",
+                  }) %>
+                <% end %>
               <% end %>
             </div>
           </div>

govuk_publishing_components.gemspec

@@ -28,6 +28,7 @@ Gem::Specification.new do |s|
   s.add_dependency "sprockets-rails"
 
   s.add_development_dependency "capybara"
+  s.add_development_dependency "climate_control"
   s.add_development_dependency "dartsass-rails"
   s.add_development_dependency "faker"
   s.add_development_dependency "gds-api-adapters"

spec/component_guide/component_index_spec.rb

@@ -1,6 +1,10 @@
 require "rails_helper"
 
 describe "Component guide index" do
+  around do |example|
+    ClimateControl.modify(GOVUK_ENABLE_SEARCH_AUTOCOMPLETE: "true") { example.run }
+  end
+
   # Load ordering test can only fail if run as the first test in suite
   # https://github.com/rails/rails/issues/12168
   it "renders using gem layout not app layout after viewing a page on the application" do

spec/components/layout_super_navigation_header_spec.rb

@@ -163,11 +163,6 @@ def component_name
     assert_select ".js-module-initialised[data-module=\"super-navigation-mega-menu\"]", false
   end
 
-  it "includes the search_with_autocomplete component with correct URL" do
-    render_component({})
-    assert_select ".gem-c-search-with-autocomplete[data-source-url='http://www.dev.gov.uk/api/search/autocomplete.json']"
-  end
-
   it "adds GA4 tracking" do
     render_component({})
 
@@ -180,4 +175,19 @@ def component_name
     assert_select 'a[data-ga4-link=\'{"event_name":"navigation","type":"header menu bar","index_section":2,"index_link":6,"index_section_count":3,"index_total":6,"section":"Government activity"}\']'
     assert_select "form[data-module='ga4-search-tracker']"
   end
+
+  describe "search autocomplete" do
+    it "includes the search_with_autocomplete component by default" do
+      render_component({})
+      assert_select ".gem-c-search-with-autocomplete[data-source-url='http://www.dev.gov.uk/api/search/autocomplete.json']"
+    end
+
+    it "allows the GOVUK_DISABLE_SEARCH_AUTOCOMPLETE env var presence to fallback to search without autocomplete" do
+      ClimateControl.modify GOVUK_DISABLE_SEARCH_AUTOCOMPLETE: "1" do
+        render_component({})
+        assert_no_selector ".gem-c-search-autocomplete"
+        assert_select ".gem-c-search"
+      end
+    end
+  end
 end

spec/rails_helper.rb

@@ -5,6 +5,7 @@
 require "rspec/rails"
 require "capybara/rails"
 require "govuk_test"
+require "climate_control"
 
 GovukTest.configure
 Selenium::WebDriver::Options.chrome(loggingPrefs: { browser: "ALL" })