Fix tag alias problems (#12480)

app/controllers/admin/tags_controller.rb

@@ -2,6 +2,12 @@ module Admin
   class TagsController < Admin::ApplicationController
     layout "admin"
 
+    ALLOWED_PARAMS = %i[
+      id supported rules_markdown short_summary pretty_name bg_color_hex
+      text_color_hex user_id alias_for badge_id requires_approval
+      category social_preview_template wiki_body_markdown submission_template
+    ].freeze
+
     before_action :set_default_options, only: %i[index]
     before_action :badges_for_options, only: %i[new create edit update]
     after_action only: [:update] do
@@ -38,6 +44,7 @@ module Admin
     def update
       @tag = Tag.find(params[:id])
       if @tag.update(tag_params)
+        ::Tags::AliasRetagWorker.perform_async(@tag.id) if tag_alias_updated?
         flash[:success] = "#{@tag.name} tag successfully updated!"
       else
         flash[:error] = "The tag update failed: #{@tag.errors_as_sentence}"
@@ -57,12 +64,11 @@ module Admin
     end
 
     def tag_params
-      allowed_params = %i[
-        id supported rules_markdown short_summary pretty_name bg_color_hex
-        text_color_hex user_id alias_for badge_id requires_approval
-        category social_preview_template wiki_body_markdown submission_template
-      ]
-      params.require(:tag).permit(allowed_params)
+      params.require(:tag).permit(ALLOWED_PARAMS)
+    end
+
+    def tag_alias_updated?
+      tag_params[:alias_for].present?
     end
   end
 end

app/workers/tags/alias_retag_worker.rb

@@ -0,0 +1,18 @@
+module Tags
+  class AliasRetagWorker
+    include Sidekiq::Worker
+
+    sidekiq_options queue: :low_priority, retry: 5
+
+    def perform(tag_id)
+      tag = Tag.find_by(id: tag_id)
+      return unless tag
+
+      tag.taggings.find_each do |tagging|
+        taggable = tagging.taggable
+        new_tag_list = ActsAsTaggableOn::TagParser.new(taggable.tag_list).parse
+        taggable.update(tag_list: new_tag_list)
+      end
+    end
+  end
+end

spec/requests/admin/tags_spec.rb

@@ -60,5 +60,19 @@ RSpec.describe "/admin/tags", type: :request do
       expect(tag.bg_color_hex).to eq(params[:bg_color_hex])
       expect(tag.text_color_hex).to eq(params[:text_color_hex])
     end
+
+    it "updates posts when making a tag an alias for another tag" do
+      create(:tag, name: "rails")
+      article1 = create(:article, tags: "ruby, ror")
+      article2 = create(:article, tags: "ror, webdev")
+      alias_tag = Tag.find_by(name: "ror")
+
+      sidekiq_perform_enqueued_jobs do
+        put admin_tag_path(alias_tag), params: { tag: { alias_for: "rails" } }
+      end
+
+      expect(article1.reload.cached_tag_list).to eq "ruby, rails"
+      expect(article2.reload.cached_tag_list).to eq "rails, webdev"
+    end
   end
 end