Use helper to create list of projects issue can be moved to

This also adds confirmation message if issue move has been requested.

app/assets/javascripts/issuable_form.js.coffee

 class @IssuableForm
+  ISSUE_MOVE_CONFIRM_MSG = 'Are you sure you want to move this issue to another project?'
+
   constructor: (@form) ->
     GitLab.GfmAutoComplete.setup()
     new UsersSelect()
@@ -6,12 +8,13 @@ class @IssuableForm
 
     @titleField       = @form.find("input[name*='[title]']")
     @descriptionField = @form.find("textarea[name*='[description]']")
+    @issueMoveField   = @form.find("#move_to_project_id")
 
     return unless @titleField.length && @descriptionField.length
 
     @initAutosave()
 
-    @form.on "submit", @resetAutosave
+    @form.on "submit", @handleSubmit
     @form.on "click", ".btn-cancel", @resetAutosave
 
   initAutosave: ->
@@ -27,6 +30,12 @@ class @IssuableForm
       "description"
     ]
 
+  handleSubmit: (e) =>
+    @resetAutosave
+
+    if (parseInt(@issueMoveField?.val()) ? 0) > 0
+      e.preventDefault() unless confirm(ISSUE_MOVE_CONFIRM_MSG)
+
   resetAutosave: =>
     @titleField.data("autosave").reset()
     @descriptionField.data("autosave").reset()

app/helpers/issues_helper.rb

@@ -57,6 +57,17 @@ module IssuesHelper
     options_from_collection_for_select(milestones, 'id', 'title', object.milestone_id)
   end
 
+  def project_options(issuable, current_user, ability: :read_project)
+    projects = current_user.authorized_projects
+    projects = projects.select do |project|
+      current_user.can?(ability, project) && project != issuable.project
+    end
+
+    projects.unshift(OpenStruct.new(id: 0, name_with_namespace: 'No project'))
+
+    options_from_collection_for_select(projects, :id, :name_with_namespace, 0)
+  end
+
   def status_box_class(item)
     if item.respond_to?(:expired?) && item.expired?
       'status-box-expired'

app/views/shared/issuable/_form.html.haml

@@ -72,9 +72,9 @@
     .form-group
       = f.label :move_to_project_id, 'Move', class: 'control-label'
       .col-sm-10
-        = project_select_tag(:move_to_project_id, placeholder: 'Select project',
-          class: 'custom-form-control', data: { 'select-id' => 'id',
-          'access-level' => Gitlab::Access::REPORTER, 'without-id' => issuable.project.id })
+        - projects = project_options(issuable, current_user, ability: :admin_issue)
+        = select_tag(:move_to_project_id, projects, include_blank: true,
+                     class: 'select2', data: { placeholder: 'Select project' })
 
 - if issuable.is_a?(MergeRequest)
   %hr

spec/services/issues/move_service_spec.rb

@@ -162,6 +162,18 @@ describe Issues::MoveService, services: true do
     end
   end
 
+  context 'moving to same project' do
+    let(:new_project) { old_project }
+
+    include_context 'issue move requested'
+    include_context 'user can move issue'
+
+    it 'raises error' do
+      expect { move_service }
+        .to raise_error(StandardError, /Cannot move issue/)
+    end
+  end
+
   context 'issue move not requested' do
     let(:new_project_id) { nil }
 
@@ -179,7 +191,6 @@ describe Issues::MoveService, services: true do
     end
   end
 
-
   describe 'move permissions' do
     include_context 'issue move requested'