Adding a processor for handling deletion of merge requests.

Replacing MergeRequests#destroy with a call to #soft_delete, which posts a message to the MQ.
This processor will both delete the ref in the target repository and delete the merge request itself.

The ref in the tracking repository is not deleted yet, nor are updates in the backend handled for merge requests
that are closed or reopened.

app/controllers/merge_requests_controller.rb

@@ -207,7 +207,7 @@ def update
   end
 
   def destroy
-    @merge_request.destroy
+    @merge_request.soft_delete
     flash[:success] = I18n.t "merge_requests_controller.destroy_success"
     redirect_to [@owner, @repository]
   end

app/models/merge_request.rb

@@ -500,6 +500,12 @@ def push_new_branch_to_tracking_repo
   def delete_target_repository_ref
     source_repository.git.git.push({},target_repository.full_repository_path, ":#{merge_branch_name}")
   end
+
+  # Since we'll be deleting the ref in the backend, this will be handled in the message queue
+  def soft_delete
+    msg = {:merge_request_id => to_param, :action => "delete"}
+    publish :merge_request_backend_updates, msg.to_json
+  end
 
   def tracking_repository
     target_repository.create_tracking_repository unless target_repository.has_tracking_repository?

app/processors/merge_request_git_backend_processor.rb

@@ -0,0 +1,45 @@
+# encoding: utf-8
+#--
+#   Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU Affero General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU Affero General Public License for more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#++
+class MergeRequestGitBackendProcessor < ApplicationProcessor
+
+  subscribes_to :merge_request_backend_updates
+
+  def on_message(message)
+    @body = ActiveSupport::JSON.decode(message)
+    send("do_#{action}")
+  end
+
+  def action
+    @body["action"].to_sym
+  end
+
+  def merge_request
+    @merge_request ||= MergeRequest.find(@body["merge_request_id"])
+  end
+
+  private
+  def do_delete
+    logger.info("Deleting tracking branch #{merge_request.merge_branch_name} for merge request in target repository #{merge_request.target_repository.id}")
+    begin
+      merge_request.delete_target_repository_ref
+    rescue Grit::NoSuchPathError => e
+      logger.error "Could not find Git path. Message is #{e.message}"
+    end
+    merge_request.destroy
+  end
+end

config/messaging.rb

@@ -14,5 +14,5 @@
   s.destination :archive_repo, '/queue/GitoriousRepositoryArchiving'
   s.destination :cc_message, '/queue/GitoriousEmailNotifications'
   s.destination :mirror_merge_request, '/queue/GitoriousMergeRequestCreation'
-
-end
+  s.destination :merge_request_backend_updates, '/queue/GitoriousMergeRequestBackend'
+end

test/functional/merge_requests_controller_test.rb

@@ -641,12 +641,13 @@ def do_delete
 			assert_equal @source_repository, assigns(:merge_request).source_repository
 		end
 
-		should "deletes the record" do
+		should "soft-delete the record" do
 			login_as :johan
+      MergeRequest.stubs(:find).returns(@merge_request)
+      @merge_request.expects(:soft_delete)
 			do_delete
 			assert_redirected_to(project_repository_path(@project, @target_repository))
 			assert_match(/merge request was retracted/i, flash[:success])
-			assert_nil MergeRequest.find_by_id(@merge_request.id)
 		end
 
 		should "only allows the owner to delete" do

test/unit/merge_request_test.rb

@@ -658,11 +658,16 @@ def setup
       @source_git.expects(:push).with({}, @merge_request.target_repository.full_repository_path, ":#{@merge_request.merge_branch_name}")
       @merge_request.delete_target_repository_ref
     end
+  end
 
-    should_eventually "delete the target repository when being closed"
-
-    should_eventually "recreate the ref in the target repository when reopened" 
-
-    should_eventually "delete both from the target and tracking repository when being deleted" 
+  context "Soft deletion of merge requests" do
+    setup do
+      @merge_request = merge_requests(:moes_to_johans_open)
+    end
+    should "send a message when being soft deleted" do
+      p = proc {@merge_request.soft_delete}
+      message = find_message_with_queue_and_regexp('/queue/GitoriousMergeRequestBackend', /.*/) {p.call}
+      assert_equal({'merge_request_id' => @merge_request.id.to_s, "action" => "delete"}, message)
+    end
   end
 end

test/unit/processors/merge_request_git_backend_processor_test.rb

@@ -0,0 +1,75 @@
+# encoding: utf-8
+#--
+#   Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU Affero General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU Affero General Public License for more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#++
+
+
+require File.dirname(__FILE__) + '/../../test_helper'
+
+class MergeRequestGitBackendProcessorTest < ActiveSupport::TestCase
+
+  def setup
+    @processor = MergeRequestGitBackendProcessor.new
+    @merge_request = merge_requests(:moes_to_johans)
+    @repository = @merge_request.target_repository
+  end
+
+  def teardown
+    @processor = nil
+  end
+
+  context "Deleting the merge request and its tracking branch" do
+    setup do
+      @msg = {:merge_request_id => @merge_request.to_param, :action => "delete"}
+      @processor.instance_variable_set("@merge_request", @merge_request)
+    end
+
+    should "delete the tracking repo and the merge request itself" do
+      @merge_request.expects(:delete_target_repository_ref).once
+      @merge_request.expects(:destroy).once
+      @processor.on_message(@msg.to_json)
+    end
+
+    should "handle non-existing target gits" do
+      @merge_request.expects(:destroy).once
+      assert_nothing_raised do
+        @processor.on_message(@msg.to_json)
+      end
+    end
+  end
+
+  context "Parsing the action" do
+    should "understand the delete command" do
+      msg = {:merge_request_id => @merge_request.to_param, :action => "delete"}
+      @processor.expects(:do_delete).once
+      @processor.on_message(msg.to_json)
+      assert_equal :delete, @processor.action
+      assert_equal @merge_request, @processor.merge_request
+    end
+
+    should "understand the close command" do
+      msg = {:merge_request_id => @merge_request.to_param, :action => "close"}
+      @processor.expects(:do_close)
+      @processor.on_message(msg.to_json)
+    end
+
+    should "understand the reopen command" do
+      msg = {:merge_request_id => @merge_request.to_param, :action => "reopen"}
+      @processor.expects(:do_reopen)
+      @processor.on_message(msg.to_json)
+    end
+  end
+end