better error message

Author: laurelfan

dashboard/app/controllers/levels_controller.rb

@@ -88,7 +88,9 @@ def update_blocks
   def update
     if level_params[:name] && @level.name.downcase == level_params[:name].downcase
       # do not allow case-only changes in the level name because that confuses git on OSX
-      params[:level][:name] = @level.name
+      @level.errors.add(:name, 'Cannot change only the capitalization of the level name (it confuses git on OSX)')
+      render json: @level.errors, status: :unprocessable_entity
+      return
     end
     if @level.update(level_params)
       render json: { redirect: level_url(@level) }.to_json

dashboard/app/views/levels/_form.html.haml

@@ -1,3 +1,11 @@
+#validation-error{style: 'background-color: yellow'}
+  - if @level.errors.any?
+    %h2
+      = pluralize(@level.errors.count, "error")
+      prohibited this level from being saved:
+    %ul
+      - @level.errors.full_messages.each do |msg|
+        %li= msg
 = form_for [@level], method: @level.new_record? ? :post : :patch, remote: true do |f|
   = f.hidden_field :type, value: @type_class.to_s.presence || @level.type
   .field
@@ -23,14 +31,6 @@
     = render partial: 'levels/editors/dsl', locals: {f: f} if @level.is_a? DSLDefined
   .actions
     = f.submit
-#validation-error
-  - if @level.errors.any?
-    %h2
-      = pluralize(@level.errors.count, "error")
-      prohibited this level from being saved:
-    %ul
-      - @level.errors.full_messages.each do |msg|
-        %li= msg
 :javascript
   #{render partial: 'shared/ajax_submit', formats: [:js],  locals: {form_selector: @level.new_record? ? '#new_level' : '.edit_level'}}
   function make_selection_handler(flag) {

dashboard/test/controllers/levels_controller_test.rb

@@ -454,6 +454,11 @@ class LevelsControllerTest < ActionController::TestCase
 
     post :update, id: level.id, level: {name: 'ORIGINAL NAME'}
 
+    assert_response 422
+
+    # error message
+    assert assigns(:level).errors[:name]
+
     level = level.reload
     # same name
     assert_equal 'original name', level.name