Require projects before creating milestone

app/controllers/groups/milestones_controller.rb

@@ -58,7 +58,7 @@ class Groups::MilestonesController < Groups::ApplicationController
 
   def render_new_with_error(empty_project_ids)
     @milestone = Milestone.new(milestone_params)
-    @milestone.errors.add(:project_id, "Please select at least one project.") if empty_project_ids
+    @milestone.errors.add(:base, "Please select at least one project.") if empty_project_ids
     render :new
   end
 

app/views/groups/milestones/new.html.haml

@@ -34,7 +34,7 @@
         = f.label :projects, "Projects", class: "control-label"
         .col-sm-10
           = f.collection_select :project_ids, @group.projects.non_archived, :id, :name,
-            { selected: @group.projects.non_archived.pluck(:id) }, multiple: true, class: 'select2'
+            { selected: @group.projects.non_archived.pluck(:id) }, required: true, multiple: true, class: 'select2'
 
     .col-md-6
       .form-group

changelogs/unreleased/milestone-project-require.yml

+---
+title: Require projects before creating milestone.
+merge_request: 7301
+author: gfyoung