Maintenance: Ensure Content-Type 'text/html' for error pages.

app/controllers/application_controller/handles_errors.rb

@@ -73,7 +73,7 @@ module ApplicationController::HandlesErrors
         @message = errors[:error_human] || errors[:error] || param[:message]
         @traceback = !Rails.env.production?
         file = File.open(Rails.root.join('public', "#{status_code}.html"), 'r')
-        render inline: file.read, status: status # rubocop:disable Rails/RenderInline
+        render inline: file.read, status: status, content_type: 'text/html' # rubocop:disable Rails/RenderInline
       end
     end
   end

spec/requests/error_spec.rb

@@ -28,6 +28,7 @@ RSpec.describe 'Error handling', type: :request do
     let(:as) { :html }
 
     it { expect(response).to have_http_status(http_status) }
+    it { expect(response.content_type).to eq('text/html') }
     it { expect(response.body).to include('<html') }
     it { expect(response.body).to include("<title>#{title}</title>") }
     it { expect(response.body).to include("<h1>#{headline}</h1>") }
@@ -37,10 +38,11 @@ RSpec.describe 'Error handling', type: :request do
   context 'URL route does not exist' do
 
     before do
-      get '/not_existing_url', as: as
+      get url, as: as
     end
 
-    let(:message) { 'No route matches [GET] /not_existing_url' }
+    let(:url) { '/not_existing_url' }
+    let(:message) { "No route matches [GET] #{url}" }
     let(:http_status) { :not_found }
 
     context 'requesting JSON' do
@@ -52,6 +54,14 @@ RSpec.describe 'Error handling', type: :request do
       let(:headline) { '404: Requested resource was not found' }
 
       include_examples 'HTML response format'
+
+      context 'when request ends with URL' do
+
+        let(:url) { "//////#{message}" }
+        let(:message) { 'this__website__is__closed__visit__our__new__site:_someother.com' }
+
+        include_examples 'HTML response format'
+      end
     end
   end