REFACTOR: move all conditions to guardian

app/assets/javascripts/discourse/views/topic-footer-buttons.js.es6

@@ -22,7 +22,7 @@ export default Discourse.ContainerView.extend({
     if (Discourse.User.current()) {
       if (!topic.get('isPrivateMessage')) {
         // We hide some controls from private messages
-        if (this.get('topic.details.can_invite_to') && (!this.get('topic.category.read_restricted') || Discourse.User.currentProp('admin'))) {
+        if (this.get('topic.details.can_invite_to')) {
           this.attachViewClass(InviteReplyButton);
         }
         this.attachViewClass(StarButton);

lib/guardian.rb

@@ -200,9 +200,9 @@ class Guardian
   end
 
   def can_invite_to?(object, group_ids=nil)
-    can_see?(object) &&
-    can_invite_to_forum? &&
-    ( group_ids.blank? || is_admin? )
+    can_invite = can_see?(object) && can_invite_to_forum? && ( group_ids.blank? || is_admin? )
+    can_invite = can_invite && ( !object.category.read_restricted || is_admin? ) if object.is_a?(Topic)
+    can_invite
   end
 
   def can_bulk_invite_to_forum?(user)

spec/components/guardian_spec.rb

@@ -241,9 +241,13 @@ describe Guardian do
   end
 
   describe 'can_invite_to?' do
+    let(:group) { Fabricate(:group) }
+    let(:category) { Fabricate(:category, read_restricted: true) }
     let(:topic) { Fabricate(:topic) }
+    let(:private_topic) { Fabricate(:topic, category: category) }
     let(:user) { topic.user }
     let(:moderator) { Fabricate(:moderator) }
+    let(:admin) { Fabricate(:admin) }
 
     it 'handles invitation correctly' do
       Guardian.new(nil).can_invite_to?(topic).should be_false
@@ -268,6 +272,14 @@ describe Guardian do
       Guardian.new(user).can_invite_to?(topic).should be_false
     end
 
+    it 'returns false for normal user on private topic' do
+      Guardian.new(user).can_invite_to?(private_topic).should be_false
+    end
+
+    it 'returns true for admin on private topic' do
+      Guardian.new(admin).can_invite_to?(private_topic).should be_true
+    end
+
   end
 
   describe 'can_see?' do
@@ -1757,4 +1769,3 @@ describe Guardian do
     end
   end
 end
-