Fix GOV.UK Chat promo on pages with multiple path segments

We have an allow list of URLs on which we want to render the GOV.UK Chat
promo, which we compare the content item's `base_path` against to
determine whether to show the promo or not.

This results in a bug in some guide pages where we only want to show the
promo on certain steps of the guide.

Let's consider the "/contracted-out" URL. This guide has 3 steps, and so
3 URLs

1. /contracted-out
2. /contracted-out/how-contracting-out-affects-your-amount
3. /contracted-out/check-if-you-were-contracted-out

We only want to show the promo on URL 1 and 3 in the list above, but not
the second one.

With the current logic, we're showing the promo on all of these URLs.
That's because we're looking at the `content_item.base_path` property,
which is "/contracted-out" for all of those URLs.

Instead we should do the comparison on the `requested_path` method,
which is the full path.

It also fixes a bug in a similar vein where we want to show the promo on
only one of the sub-pages in a guide (e.g. URL 2 above), but because
we're comparing against the `base_path`, we end up showing it on all
pages of the guide.

app/helpers/govuk_chat_promo_helper.rb

@@ -1,5 +1,5 @@
 module GovukChatPromoHelper
-  GOVUK_CHAT_PROMO_BASE_PATHS = %w[
+  GOVUK_CHAT_PROMO_PATHS = %w[
     /business-asset-disposal-relief
     /business-support-service
     /capital-gains-tax
@@ -65,7 +65,7 @@ module GovukChatPromoHelper
     /write-business-plan
   ].freeze
 
-  def show_govuk_chat_promo?(base_path)
-    ENV["GOVUK_CHAT_PROMO_ENABLED"] == "true" && GOVUK_CHAT_PROMO_BASE_PATHS.include?(base_path)
+  def show_govuk_chat_promo?(path)
+    ENV["GOVUK_CHAT_PROMO_ENABLED"] == "true" && GOVUK_CHAT_PROMO_PATHS.include?(path)
   end
 end

app/views/shared/_sidebar_navigation.html.erb

@@ -1,7 +1,7 @@
 <% content_item = @content_item.content_item.parsed_content %>
 
 <div class="govuk-grid-column-one-third">
-  <% if show_govuk_chat_promo?(@content_item.base_path) %>
+  <% if show_govuk_chat_promo?(@content_item.requested_path) %>
     <%= render "govuk_publishing_components/components/chat_entry", { margin_top_until_tablet: true } %>
   <% end %>
 

test/helpers/govuk_chat_promo_helper_test.rb

@@ -2,7 +2,7 @@
 
 class GovukChatPromoHelperTest < ActionView::TestCase
   test "show_govuk_chat_promo? when configuration disabled" do
-    assert_not show_govuk_chat_promo?(GOVUK_CHAT_PROMO_BASE_PATHS.first)
+    assert_not show_govuk_chat_promo?(GOVUK_CHAT_PROMO_PATHS.first)
   end
 
   test "show_govuk_chat_promo? when base_path not in configuration" do
@@ -13,7 +13,7 @@ class GovukChatPromoHelperTest < ActionView::TestCase
 
   test "show_govuk_chat_promo? when base_path is in configuration" do
     ClimateControl.modify GOVUK_CHAT_PROMO_ENABLED: "true" do
-      assert show_govuk_chat_promo?(GOVUK_CHAT_PROMO_BASE_PATHS.first)
+      assert show_govuk_chat_promo?(GOVUK_CHAT_PROMO_PATHS.first)
     end
   end
 end

test/integration/govuk_chat_promo_test.rb

@@ -1,15 +1,31 @@
 require "test_helper"
 
 class GovukChatPromoTest < ActionDispatch::IntegrationTest
-  test "renders GOV.UK chat promo for matching content type and base path" do
+  test "renders GOV.UK chat promo for matching content type and requested path" do
     ClimateControl.modify GOVUK_CHAT_PROMO_ENABLED: "true" do
-      setup_and_visit_a_page_with_specific_base_path("answer", GovukChatPromoHelper::GOVUK_CHAT_PROMO_BASE_PATHS.first)
+      setup_and_visit_a_page_with_specific_base_path("guide", "/contracted-out")
 
       assert page.has_css?(".gem-c-chat-entry")
     end
   end
 
+  test "renders GOV.UK chat promo when requested path contains multiple parts" do
+    ClimateControl.modify GOVUK_CHAT_PROMO_ENABLED: "true" do
+      setup_and_visit_a_page_with_specific_base_path("guide", "/contracted-out/how-contracting-out-affects-your-amount")
+
+      assert page.has_css?(".gem-c-chat-entry")
+    end
+  end
+
+  test "does not render GOV.UK chat promo when base path is in allow list but actual path is not" do
+    ClimateControl.modify GOVUK_CHAT_PROMO_ENABLED: "true" do
+      setup_and_visit_a_page_with_specific_base_path("guide", "/contracted-out/check-if-you-were-contracted-out")
+
+      assert_not page.has_css?(".gem-c-chat-entry")
+    end
+  end
+
   def schema_type
-    "answer"
+    "guide"
   end
 end