DEV: Allow CSP to be enabled during QUnit tests (#8668)

The QUnit rake task starts a server in test mode. We need a tweak to allow dynamic CSP hostnames in test mode. This tweak is already present in development mode.

To allow CSP to work, the browser host/port must match what the server sees. Therefore we need to disable the enforce_hostname middleware in test mode. To keep rspec and production as similar as possible, we skip enforce_hostname using an environment variable.

Also move the qunit rake task to use unicorn, for consistency with development and production.

lib/tasks/qunit.rake

@@ -2,14 +2,10 @@
 
 desc "Runs the qunit test suite"
 
-task "qunit:test", [:timeout, :qunit_path] => :environment do |_, args|
-  require "rack"
+task "qunit:test", [:timeout, :qunit_path] do |_, args|
   require "socket"
   require 'rbconfig'
 
-  puts "Turning off CSP to allow qunit to run"
-  SiteSetting.content_security_policy = false
-
   if RbConfig::CONFIG['host_os'][/darwin|mac os/]
     google_chrome_cli = "/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome"
   else
@@ -45,14 +41,16 @@ task "qunit:test", [:timeout, :qunit_path] => :environment do |_, args|
     port += 1
   end
 
-  unless pid = fork
-    Discourse.after_fork
-    Rack::Server.start(config: "config.ru",
-                       AccessLog: [],
-                       environment: 'test',
-                       Port: port)
-    exit
-  end
+  pid = Process.spawn(
+    {
+      "RAILS_ENV" => "test",
+      "SKIP_ENFORCE_HOSTNAME" => "1",
+      "UNICORN_PID_PATH" => "#{Rails.root}/tmp/pids/unicorn_test.pid", # So this can run alongside development
+      "UNICORN_PORT" => port.to_s,
+      "UNICORN_SIDEKIQS" => "0"
+    },
+    "#{Rails.root}/bin/unicorn -c config/unicorn.conf.rb"
+  )
 
   begin
     success = true