Feature: delegate all open discussions to Issue

When a merge request can only be merged when all discussions are
resolved. This feature allows to easily delegate those discussions to a
new issue, while marking them as resolved in the merge request.

The user is presented with a new issue, prepared with mentions of all
unresolved discussions, including the first unresolved note of the
discussion, time and link to the note.

When the issue is created, the discussions in the merge request will get
a system note directing the user to the newly created issue.

2 files changed, 14 insertions, 5 deletions

diff --git a/app/controllers/projects/discussions_controller.rb b/app/controllers/projects/discussions_controller.rb
index d174e1145a7..148e39630e3 100644
--- a/app/controllers/projects/discussions_controller.rb
+++ b/app/controllers/projects/discussions_controller.rb
@@ -5,9 +5,7 @@ class Projects::DiscussionsController < Projects::ApplicationController
   before_action :authorize_resolve_discussion!
 
   def resolve
-    discussion.resolve!(current_user)
-
-    MergeRequests::ResolvedDiscussionNotificationService.new(project, current_user).execute(merge_request)
+    Discussions::ResolveService.new(project, current_user, merge_request: merge_request).execute(discussion)
 
     render json: {
       resolved_by: discussion.resolved_by.try(:name),
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 4aea7bb62c4..4f66e01e0f7 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -46,8 +46,9 @@ class Projects::IssuesController < Projects::ApplicationController
     params[:issue] ||= ActionController::Parameters.new(
       assignee_id: ""
     )
+    build_params = issue_params.merge(merge_request_for_resolving_discussions: merge_request_for_resolving_discussions)
+    @issue = @noteable = Issues::BuildService.new(project, current_user, build_params).execute
 
-    @issue = @noteable = @project.issues.new(issue_params)
     respond_with(@issue)
   end
 
@@ -75,7 +76,9 @@ class Projects::IssuesController < Projects::ApplicationController
   end
 
   def create
-    @issue = Issues::CreateService.new(project, current_user, issue_params.merge(request: request)).execute
+    extra_params = { request: request,
+                     merge_request_for_resolving_discussions: merge_request_for_resolving_discussions }
+    @issue = Issues::CreateService.new(project, current_user, issue_params.merge(extra_params)).execute
 
     respond_to do |format|
       format.html do
@@ -169,6 +172,14 @@ class Projects::IssuesController < Projects::ApplicationController
   alias_method :awardable, :issue
   alias_method :spammable, :issue
 
+  def merge_request_for_resolving_discussions
+    return unless merge_request_iid = params[:merge_request_for_resolving_discussions]
+
+    @merge_request_for_resolving_discussions ||= MergeRequestsFinder.new(current_user, project_id: project.id).
+                                                   execute.
+                                                   find_by(iid: merge_request_iid)
+  end
+
   def authorize_read_issue!
     return render_404 unless can?(current_user, :read_issue, @issue)
   end