Fix missing avatars on topic list page.

Introduced in b50fab2d72

app/serializers/concerns/topic_tags_mixin.rb

@@ -14,17 +14,11 @@ module TopicTagsMixin
     if scope.is_staff?
       tags
     else
-      tags - (@options[:hidden_tag_names] || hidden_tag_names)
+      tags - scope.hidden_tag_names
     end
   end
 
   def topic
     object.is_a?(Topic) ? object : object.topic
   end
-
-  private
-
-  def hidden_tag_names
-    @hidden_tag_names ||= DiscourseTagging.hidden_tag_names(scope)
-  end
 end

app/serializers/topic_list_serializer.rb

@@ -9,27 +9,12 @@ class TopicListSerializer < ApplicationSerializer
              :per_page,
              :top_tags,
              :tags,
-             :shared_drafts,
+             :shared_drafts
-             :topics
 
+  has_many :topics, serializer: TopicListItemSerializer, embed: :objects
   has_many :shared_drafts, serializer: TopicListItemSerializer, embed: :objects
   has_many :tags, serializer: TagSerializer, embed: :objects
 
-  def topics
-    opts = {
-      scope: scope,
-      root: false
-    }
-
-    if SiteSetting.tagging_enabled && !scope.is_staff?
-      opts.merge!(hidden_tag_names: DiscourseTagging.hidden_tag_names(scope))
-    end
-
-    object.topics.map do |topic|
-      TopicListItemSerializer.new(topic, opts)
-    end
-  end
-
   def can_create_topic
     scope.can_create?(Topic)
   end

lib/guardian/tag_guardian.rb

@@ -23,4 +23,14 @@ module TagGuardian
   def can_admin_tag_groups?
     is_staff? && SiteSetting.tagging_enabled
   end
+
+  def hidden_tag_names
+    @hidden_tag_names ||= begin
+      if SiteSetting.tagging_enabled && !is_staff?
+        DiscourseTagging.hidden_tag_names(self)
+      else
+        []
+      end
+    end
+  end
 end

spec/serializers/topic_list_serializer_spec.rb

@@ -0,0 +1,23 @@
+require 'rails_helper'
+
+RSpec.describe TopicListSerializer do
+  let(:user) { Fabricate(:user) }
+
+  let(:topic) do
+    Fabricate(:topic).tap do |t|
+      t.allowed_user_ids = [t.user_id]
+    end
+  end
+
+  it 'should return the right payload' do
+    topic_list = TopicList.new(nil, user, [topic])
+
+    serialized = described_class.new(topic_list,
+      scope: Guardian.new(user)
+    ).as_json
+
+    expect(serialized[:users].first[:id]).to eq(topic.user_id)
+    expect(serialized[:primar_groups]).to eq([])
+    expect(serialized[:topic_list][:topics].first[:id]).to eq(topic.id)
+  end
+end