Delegate bulk operations to a `TopicsBulkAction` object.

app/controllers/topics_controller.rb

@@ -1,6 +1,7 @@
 require_dependency 'topic_view'
 require_dependency 'promotion'
 require_dependency 'url_helper'
+require_dependency 'topics_bulk_action'
 
 class TopicsController < ApplicationController
   include UrlHelper
@@ -269,7 +270,11 @@ class TopicsController < ApplicationController
 
   def bulk
     topic_ids = params.require(:topic_ids).map {|t| t.to_i}
-    render_json_dump topic_ids: topic_ids
+    operation = params.require(:operation).symbolize_keys
+    raise ActionController::ParameterMissing.new(:operation_type) if operation[:type].blank?
+    operator = TopicsBulkAction.new(current_user, topic_ids, operation)
+    changed_topic_ids = operator.perform!
+    render_json_dump topic_ids: changed_topic_ids
   end
 
   private

lib/topics_bulk_action.rb

@@ -0,0 +1,14 @@
+class TopicsBulkAction
+
+  def initialize(user, topic_ids, operation)
+    @user = user
+    @topic_ids = topic_ids
+    @operation = operation
+  end
+
+  def perform!
+    []
+  end
+
+end
+

spec/controllers/topics_controller_spec.rb

@@ -781,4 +781,34 @@ describe TopicsController do
 
   end
 
+  describe "bulk" do
+    it 'needs you to be logged in' do
+      lambda { xhr :put, :bulk }.should raise_error(Discourse::NotLoggedIn)
+    end
+
+    describe "when logged in" do
+      let!(:user) { log_in }
+      let(:operation) { {type: 'change_category', category_id: '1'} }
+      let(:topic_ids) { [1,2,3] }
+
+      it "requires a list of topic_ids" do
+        lambda { xhr :put, :bulk, operation: operation }.should raise_error(ActionController::ParameterMissing)
+      end
+
+      it "requires an operation param" do
+        lambda { xhr :put, :bulk, topic_ids: topic_ids}.should raise_error(ActionController::ParameterMissing)
+      end
+
+      it "requires a type field for the operation param" do
+        lambda { xhr :put, :bulk, topic_ids: topic_ids, operation: {}}.should raise_error(ActionController::ParameterMissing)
+      end
+
+      it "delegates work to `TopicsBulkAction`" do
+        topics_bulk_action = mock
+        TopicsBulkAction.expects(:new).with(user, topic_ids, operation).returns(topics_bulk_action)
+        topics_bulk_action.expects(:perform!)
+        xhr :put, :bulk, topic_ids: topic_ids, operation: operation
+      end
+    end
+  end
 end