Add unfurl support for /search

This change adds meta tags for slack link unfurling using
page_description and page_card_attributes methods.

app/views/search/show.html.haml

@@ -2,6 +2,10 @@
 - page_title @search_term
 - @hide_breadcrumbs = true
 
+- if @search_results
+  - page_description(_("%{count} %{scope} for term '%{term}'") % { count: @search_results.formatted_count(@scope), scope: @scope, term: @search_term })
+  - page_card_attributes("Namespace" => @group&.full_path, "Project" => @project&.full_path)
+
 .page-title-holder.d-sm-flex.align-items-sm-center
   %h1.page-title<
     = _('Search')

changelogs/unreleased/225213-unfurl-search-page.yml

+---
+title: Improve unfurling support for /search
+merge_request: 38699
+author:
+type: other

locale/gitlab.pot

@@ -333,6 +333,9 @@ msgstr ""
 msgid "%{cores} cores"
 msgstr ""
 
+msgid "%{count} %{scope} for term '%{term}'"
+msgstr ""
+
 msgid "%{count} LOC/commit"
 msgstr ""
 

spec/views/search/show.html.haml_spec.rb

@@ -33,5 +33,37 @@ RSpec.describe 'search/show' do
       expect(rendered).to render_template('search/_category')
       expect(rendered).to render_template('search/_results')
     end
+
+    context 'unfurling support' do
+      let(:group) { build(:group) }
+      let(:search_results) do
+        instance_double(Gitlab::GroupSearchResults).tap do |double|
+          allow(double).to receive(:formatted_count).and_return(0)
+        end
+      end
+
+      before do
+        assign(:search_results, search_results)
+        assign(:scope, 'issues')
+        assign(:group, group)
+      end
+
+      it 'renders meta tags for a group' do
+        render
+
+        expect(view.page_description).to match(/\d+ issues for term '#{search_term}'/)
+        expect(view.page_card_attributes).to eq("Namespace" => group.full_path)
+      end
+
+      it 'renders meta tags for both group and project' do
+        project = build(:project, group: group)
+        assign(:project, project)
+
+        render
+
+        expect(view.page_description).to match(/\d+ issues for term '#{search_term}'/)
+        expect(view.page_card_attributes).to eq("Namespace" => group.full_path, "Project" => project.full_path)
+      end
+    end
   end
 end