Change image card to use shared helper for heading

- update shared helper to return a span if heading level 0 is passed, instead of a heading level
- retain the default of h2 if nothing or an invalid value is passed

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

@@ -2,6 +2,7 @@
   brand ||= false
   brand_helper = GovukPublishingComponents::AppHelpers::BrandHelper.new(brand)
   card_helper = GovukPublishingComponents::Presenters::ImageCardHelper.new(local_assigns)
+  shared_helper = GovukPublishingComponents::Presenters::SharedHelper.new(local_assigns)
 %>
 <% if card_helper.href || card_helper.extra_links.any? %>
   <div class="gem-c-image-card <%= "gem-c-image-card--large" if card_helper.large %> <%= brand_helper.brand_class %>"
@@ -13,7 +14,7 @@
       <%= card_helper.context %>
 
       <% if card_helper.heading_text %>
-        <%= content_tag(card_helper.heading_tag,
+        <%= content_tag(shared_helper.get_heading_level,
           class: "gem-c-image-card__title") do %>
             <% if card_helper.href %>
               <%= link_to card_helper.heading_text, card_helper.href,

lib/govuk_publishing_components/presenters/image_card_helper.rb

@@ -16,7 +16,6 @@ def initialize(local_assigns)
         @description = local_assigns[:description]
         @large = local_assigns[:large]
         @heading_text = local_assigns[:heading_text]
-        @heading_level = local_assigns[:heading_level] || 2
         @extra_links_no_indent = local_assigns[:extra_links_no_indent]
         @metadata = local_assigns[:metadata]
       end
@@ -59,11 +58,6 @@ def context
         end
       end
 
-      def heading_tag
-        return "h#{@heading_level}" if [1, 2, 3, 4, 5, 6].include? @heading_level
-        return "span" if @heading_level.zero?
-      end
-
       def description
         content_tag(:div, @description, class: "gem-c-image-card__description") if @description
       end

lib/govuk_publishing_components/presenters/shared_helper.rb

@@ -14,7 +14,9 @@ def get_margin_bottom
       end
 
       def get_heading_level
-        [*1..6].include?(@heading_level) ? "h#{@heading_level}" : "h2"
+        return [*1..6].include?(@heading_level) ? "h#{@heading_level}" : "h2" unless @heading_level.zero?
+
+        "span"
       end
     end
   end

spec/lib/components/shared_helper_spec.rb

@@ -35,5 +35,11 @@
       heading = shared_helper.get_heading_level
       expect(heading).to eql('h2')
     end
+
+    it "returns a span instead of a heading if heading level is 0" do
+      shared_helper = GovukPublishingComponents::Presenters::SharedHelper.new(heading_level: 0)
+      result = shared_helper.get_heading_level
+      expect(result).to eql('span')
+    end
   end
 end