Create wiki link partial and use in all sidebars

Use wiki link partial in group and project sidebars

app/views/layouts/nav/sidebar/_group.html.haml

@@ -124,18 +124,7 @@
       = render 'layouts/nav/sidebar/analytics_links', links: group_analytics_navbar_links(@group, current_user)
 
       - if group_sidebar_link?(:wiki)
-        - wiki_url = @group.wiki.web_url
-        = nav_link(controller: :wikis) do
-          = link_to wiki_url, class: 'shortcuts-wiki', data: { qa_selector: 'wiki_link' } do
-            .nav-icon-container
-              = sprite_icon('book')
-            %span.nav-item-name
-              = _('Wiki')
-          %ul.sidebar-sub-level-items.is-fly-out-only
-            = nav_link(controller: :wikis, html_options: { class: "fly-out-top-item" } ) do
-              = link_to wiki_url do
-                %strong.fly-out-top-item-name
-                  = _('Wiki')
+        = render 'layouts/nav/sidebar/wiki_link', wiki_url: @group.wiki.web_url
 
       - if group_sidebar_link?(:group_members)
         = nav_link(path: 'group_members#index') do

app/views/layouts/nav/sidebar/_project.html.haml

@@ -308,18 +308,7 @@
                   = _('Confluence')
 
       - if project_nav_tab? :wiki
-        - wiki_url = wiki_path(@project.wiki)
-        = nav_link(controller: :wikis) do
-          = link_to wiki_url, class: 'shortcuts-wiki', data: { qa_selector: 'wiki_link' } do
-            .nav-icon-container
-              = sprite_icon('book')
-            %span.nav-item-name
-              = _('Wiki')
-          %ul.sidebar-sub-level-items.is-fly-out-only
-            = nav_link(controller: :wikis, html_options: { class: "fly-out-top-item" } ) do
-              = link_to wiki_url do
-                %strong.fly-out-top-item-name
-                  = _('Wiki')
+        = render 'layouts/nav/sidebar/wiki_link', wiki_url: wiki_path(@project.wiki)
 
       - if project_nav_tab?(:external_wiki)
         - external_wiki_url = @project.external_wiki.external_wiki_url

app/views/layouts/nav/sidebar/_wiki_link.html.haml

+= nav_link(controller: :wikis) do
+  = link_to wiki_url, class: 'shortcuts-wiki', data: { qa_selector: 'wiki_link' } do
+    .nav-icon-container
+      = sprite_icon('book')
+    %span.nav-item-name
+      = _('Wiki')
+  %ul.sidebar-sub-level-items.is-fly-out-only
+    = nav_link(controller: :wikis, html_options: { class: "fly-out-top-item" } ) do
+      = link_to wiki_url do
+        %strong.fly-out-top-item-name
+          = _('Wiki')

ee/spec/views/layouts/nav/sidebar/_group.html.haml_spec.rb

@@ -200,6 +200,39 @@ RSpec.describe 'layouts/nav/sidebar/_group' do
     end
   end
 
+  describe 'wiki tab' do
+    let(:can_read_wiki) { true }
+    let_it_be(:current_user) { create(:user) }
+
+    before do
+      group.add_guest(current_user)
+
+      allow(view).to receive(:current_user).and_return(current_user)
+      allow(view).to receive(:can?).with(current_user, :read_wiki, group).and_return(can_read_wiki)
+
+      # TODO can be removed with https://gitlab.com/gitlab-org/gitlab/-/issues/207888
+      stub_feature_flags(group_wiki: true)
+    end
+
+    describe 'when wiki is available to user' do
+      it 'shows the wiki tab with the wiki internal link' do
+        render
+
+        expect(rendered).to have_link('Wiki', href: group.wiki.web_url)
+      end
+    end
+
+    describe 'when wiki is unavailable to user' do
+      let(:can_read_wiki) { false }
+
+      it 'does not show the wiki tab' do
+        render
+
+        expect(rendered).not_to have_link('Wiki', href: group.wiki.web_url)
+      end
+    end
+  end
+
   describe 'iterations link' do
     let_it_be(:current_user) { create(:user) }