s

app/controllers/concerns/sab_pages_testable.rb

@@ -0,0 +1,39 @@
+module SabPagesTestable
+  CUSTOM_DIMENSION = 65
+
+  def self.included(base)
+    base.helper_method(
+      :sab_page_variant,
+      :is_testable_sab_page?,
+      :should_show_sab_intervention?,
+    )
+    base.after_action :set_test_response_header
+  end
+
+  def sab_page_variant
+    @sab_page_variant ||= sab_page_test.requested_variant(request.headers)
+  end
+
+  def is_testable_sab_page?
+    request.headers["HTTP_GOVUK_ABTEST_ISSTARTABUSINESSPAGE"] == "true"
+  end
+
+  def should_show_sab_intervention?
+    sab_page_variant.variant?("B") && is_testable_sab_page?
+  end
+
+private
+
+  def sab_page_test
+    @sab_page_test ||= GovukAbTesting::AbTest.new(
+      "StartABusinessSegment",
+      dimension: CUSTOM_DIMENSION,
+      allowed_variants: %w[A B C],
+      control_variant: "A",
+    )
+  end
+
+  def set_test_response_header
+    sab_page_variant.configure_response(response)
+  end
+end

app/controllers/content_items_controller.rb

@@ -1,5 +1,6 @@
 class ContentItemsController < ApplicationController
   include GovukPersonalisation::AccountConcern
+  include SabPagesTestable
   rescue_from GdsApi::HTTPForbidden, with: :error_403
   rescue_from GdsApi::HTTPNotFound, with: :error_notfound
   rescue_from GdsApi::HTTPGone, with: :error_410

app/views/content_items/_body_with_related_links.html.erb

@@ -3,13 +3,14 @@
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
     <%= render 'govuk_publishing_components/components/title',
-        title: @content_item.title %>
+      title: @content_item.title %>
   </div>
 </div>
-
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
     <div class="responsive-bottom-margin">
+      <%= render 'govuk_publishing_components/components/intervention' if should_show_sab_intervention? %>
+
       <%= render 'govuk_publishing_components/components/govspeak', {
         direction: page_text_direction,
         disable_youtube_expansions: true,

app/views/content_items/document_collection.html.erb

@@ -26,6 +26,8 @@
     <%= render 'components/important-metadata',
         items: @content_item.important_metadata %>
 
+    <%= render 'govuk_publishing_components/components/intervention' if should_show_sab_intervention? %>
+
     <%= render "components/contents-list-with-body", contents: @content_item.contents do %>
       <div class="responsive-bottom-margin">
         <%= render 'document_collection_body' %>

app/views/content_items/guide.html.erb

@@ -18,6 +18,8 @@
   <div class="govuk-grid-column-two-thirds">
     <%= render 'govuk_publishing_components/components/title', { title: @content_item.content_title } %>
 
+    <%= render 'govuk_publishing_components/components/intervention' if should_show_sab_intervention? %>
+
     <% if @content_item.show_guide_navigation? %>
       <%= render "govuk_publishing_components/components/skip_link", {
         text: t("guide.skip_to_contents"),

app/views/layouts/application.html.erb

@@ -22,6 +22,7 @@
   <%= javascript_include_tag "application", integrity: false %>
   <%= csrf_meta_tags %>
   <%= render 'govuk_publishing_components/components/meta_tags', content_item: @content_item.content_item %>
+  <%= sab_page_variant.analytics_meta_tag.html_safe if is_testable_sab_page? %>
 
   <% if @content_item.description %>
     <meta name="description" content="<%= strip_tags(@content_item.description) %>" />

test/controllers/sab_ab_test.rb

@@ -0,0 +1,86 @@
+require "test_helper"
+
+class ContentItemsControllerTest < ActionController::TestCase
+  include GovukAbTesting::MinitestHelpers
+  INTERVENTION_CSS_SELECTOR = "gem-c-intervention".freeze
+
+  test "shows intervention for variant B" do
+    for_each_schema do |schema|
+      with_variant StartABusinessSegment: "B" do
+        with_is_sab_page_header("true") do
+          set_up_and_visit_content_item_for_schema(schema)
+          assert has_intervention_css_selector
+        end
+      end
+    end
+  end
+
+  test "doesn't show intervention for variant A" do
+    for_each_schema do |schema|
+      with_variant StartABusinessSegment: "A" do
+        with_is_sab_page_header("true") do
+          set_up_and_visit_content_item_for_schema(schema)
+
+          assert_not has_intervention_css_selector
+        end
+      end
+    end
+  end
+
+  test "doesn't show intervention for variant C" do
+    for_each_schema do |schema|
+      with_variant StartABusinessSegment: "C" do
+        with_is_sab_page_header("true") do
+          set_up_and_visit_content_item_for_schema(schema)
+
+          assert_not has_intervention_css_selector
+        end
+      end
+    end
+  end
+
+  test "doesn't show intervention if SaB header is not included" do
+    for_each_schema do |schema|
+      with_variant StartABusinessSegment: "B", assert_meta_tag: false do
+        set_up_and_visit_content_item_for_schema(schema)
+
+        assert_not has_intervention_css_selector
+      end
+    end
+  end
+
+  test "doesn't show intervention if SaB header is set to false" do
+    for_each_schema do |schema|
+      with_variant StartABusinessSegment: "B", assert_meta_tag: false do
+        with_is_sab_page_header("false") do
+          set_up_and_visit_content_item_for_schema(schema)
+
+          assert_not has_intervention_css_selector
+        end
+      end
+    end
+  end
+
+private
+
+  def set_up_and_visit_content_item_for_schema(schema)
+    content_item = content_store_has_schema_example(schema, schema)
+    stub_content_store_has_item(content_item["base_path"], content_item)
+    path = content_item["base_path"][1..]
+
+    get :show, params: { path: path }
+  end
+
+  def has_intervention_css_selector
+    response.body.include?(INTERVENTION_CSS_SELECTOR)
+  end
+
+  def with_is_sab_page_header(is_sab_header)
+    request.headers["HTTP_GOVUK_ABTEST_ISSTARTABUSINESSPAGE"] = is_sab_header
+    yield
+  end
+
+  def for_each_schema(&block)
+    %w[guide answer document_collection].each(&block)
+  end
+end