fix: Undefined method `length' for nil:NilClass (#8491)

app/helpers/portal_helper.rb

@@ -64,6 +64,8 @@ module PortalHelper
 
   def thumbnail_bg_color(username)
     colors = ['#6D95BA', '#A4C3C3', '#E19191']
+    return colors.sample if username.blank?
+
     colors[username.length % colors.size]
   end
 end

spec/helpers/portal_helper_spec.rb

@@ -249,7 +249,7 @@ describe PortalHelper do
 
   describe '#thumbnail_bg_color' do
     it 'returns the correct color based on username length' do
-      expect(helper.thumbnail_bg_color('')).to eq('#6D95BA') # Length 0, so index is 0
+      expect(helper.thumbnail_bg_color('')).to be_in(['#6D95BA', '#A4C3C3', '#E19191'])
       expect(helper.thumbnail_bg_color('Joe')).to eq('#6D95BA') # Length 3, so index is 0
       expect(helper.thumbnail_bg_color('John')).to eq('#A4C3C3') # Length 4, so index is 1
       expect(helper.thumbnail_bg_color('Jane james')).to eq('#A4C3C3') # Length 10, so index is 1