Make the user dropdown reusable

We will reuse the the dropdown, but exclude some menu items based on
permissions.

So moving the menu to a partial, and adding checks for each menu item here.

app/helpers/users_helper.rb

@@ -23,9 +23,31 @@ module UsersHelper
     profile_tabs.include?(tab)
   end
 
+  def current_user_menu_items
+    @current_user_menu_items ||= get_current_user_menu_items
+  end
+
+  def current_user_menu?(item)
+    current_user_menu_items.include?(item)
+  end
+
   private
 
   def get_profile_tabs
     [:activity, :groups, :contributed, :projects, :snippets]
   end
+
+  def get_current_user_menu_items
+    items = [:help, :sign_out]
+
+    if can?(current_user, :read_user, current_user)
+      items << :profile
+    end
+
+    if can?(current_user, :update_user, current_user)
+      items << :settings
+    end
+
+    items
+  end
 end

app/policies/user_policy.rb

@@ -8,6 +8,8 @@ class UserPolicy < BasePolicy
   rule { ~restricted_public_level }.enable :read_user
   rule { ~anonymous }.enable :read_user
 
-  rule { user_is_self | admin }.enable :destroy_user
-  rule { subject_ghost }.prevent :destroy_user
+  rule { ~subject_ghost & (user_is_self | admin) }.policy do
+    enable :destroy_user
+    enable :update_user
+  end
 end

app/views/layouts/header/_current_user_dropdown.html.haml

+- return unless current_user
+
+%ul
+  %li.current-user
+    .user-name.bold
+      = current_user.name
+    = current_user.to_reference
+  %li.divider
+  - if current_user_menu?(:profile)
+    %li
+      = link_to s_("CurrentUser|Profile"), current_user, class: 'profile-link', data: { user: current_user.username }
+  - if current_user_menu?(:settings)
+    %li
+      = link_to s_("CurrentUser|Settings"), profile_path
+  - if current_user_menu?(:help)
+    %li
+      = link_to _("Help"), help_path
+  - if current_user_menu?(:help) || current_user_menu?(:settings) || current_user_menu?(:profile)
+    %li.divider
+  - if current_user_menu?(:sign_out)
+    %li
+      = link_to _("Sign out"), destroy_user_session_path, class: "sign-out-link"

app/views/layouts/header/_default.html.haml

@@ -53,22 +53,7 @@
                 = image_tag avatar_icon_for_user(current_user, 23), width: 23, height: 23, class: "header-user-avatar qa-user-avatar"
                 = sprite_icon('angle-down', css_class: 'caret-down')
               .dropdown-menu-nav.dropdown-menu-align-right
-                %ul
-                  %li.current-user
-                    .user-name.bold
-                      = current_user.name
-                    @#{current_user.username}
-                  %li.divider
-                  %li
-                    = link_to "Profile", current_user, class: 'profile-link', data: { user: current_user.username }
-                  %li
-                    = link_to "Settings", profile_path
-                  - if current_user
-                    %li
-                      = link_to "Help", help_path
-                  %li.divider
-                  %li
-                    = link_to "Sign out", destroy_user_session_path, class: "sign-out-link"
+                = render 'layouts/header/current_user_dropdown'
           - if header_link?(:admin_impersonation)
             %li.impersonation
               = link_to admin_impersonation_path, class: 'impersonation-btn', method: :delete, title: "Stop impersonation", aria: { label: 'Stop impersonation' }, data: { toggle: 'tooltip', placement: 'bottom', container: 'body' } do

qa/qa/page/menu/main.rb

@@ -2,12 +2,15 @@ module QA
   module Page
     module Menu
       class Main < Page::Base
+        view 'app/views/layouts/header/_current_user_dropdown.html.haml' do
+          element :user_sign_out_link, 'link_to _("Sign out")'
+          element :settings_link, 'link_to s_("CurrentUser|Settings")'
+        end
+
         view 'app/views/layouts/header/_default.html.haml' do
           element :navbar
           element :user_avatar
           element :user_menu, '.dropdown-menu-nav'
-          element :user_sign_out_link, 'link_to "Sign out"'
-          element :settings_link, 'link_to "Settings"'
         end
 
         view 'app/views/layouts/nav/_dashboard.html.haml' do

spec/helpers/users_helper_spec.rb

@@ -27,4 +27,29 @@ describe UsersHelper do
       expect(tabs).to include(:activity, :groups, :contributed, :projects, :snippets)
     end
   end
+
+  describe '#current_user_menu_items' do
+    subject(:items) { helper.current_user_menu_items }
+
+    before do
+      allow(helper).to receive(:current_user).and_return(user)
+      allow(helper).to receive(:can?).and_return(false)
+    end
+
+    it 'includes all default items' do
+      expect(items).to include(:help, :sign_out)
+    end
+
+    it 'includes the profile tab if the user can read themself' do
+      expect(helper).to receive(:can?).with(user, :read_user, user) { true }
+
+      expect(items).to include(:profile)
+    end
+
+    it 'includes the settings tab if the user can update themself' do
+      expect(helper).to receive(:can?).with(user, :read_user, user) { true }
+
+      expect(items).to include(:profile)
+    end
+  end
 end

spec/policies/user_policy_spec.rb

@@ -10,28 +10,36 @@ describe UserPolicy do
     it { is_expected.to be_allowed(:read_user) }
   end
 
-  describe "destroying a user" do
+  shared_examples 'changing a user' do |ability|
     context "when a regular user tries to destroy another regular user" do
-      it { is_expected.not_to be_allowed(:destroy_user) }
+      it { is_expected.not_to be_allowed(ability) }
     end
 
     context "when a regular user tries to destroy themselves" do
       let(:current_user) { user }
 
-      it { is_expected.to be_allowed(:destroy_user) }
+      it { is_expected.to be_allowed(ability) }
     end
 
     context "when an admin user tries to destroy a regular user" do
       let(:current_user) { create(:user, :admin) }
 
-      it { is_expected.to be_allowed(:destroy_user) }
+      it { is_expected.to be_allowed(ability) }
     end
 
     context "when an admin user tries to destroy a ghost user" do
       let(:current_user) { create(:user, :admin) }
       let(:user) { create(:user, :ghost) }
 
-      it { is_expected.not_to be_allowed(:destroy_user) }
+      it { is_expected.not_to be_allowed(ability) }
     end
   end
+
+  describe "destroying a user" do
+    it_behaves_like 'changing a user', :destroy_user
+  end
+
+  describe "updating a user" do
+    it_behaves_like 'changing a user', :update_user
+  end
 end