Render views outside of the standard request context (i.e. ActiveJob) with Devise/Warden

example_job.rb

class ExampleJob < ApplicationJob
  queue_as :default
  
  def perform(user)
    # do some work
    
    # HACK: get around limitations in devise/warden when rendering
    #       views outside the context of a formal http request
    renderer = ::ApplicationController.renderer.new
    renderer_env = renderer.instance_eval { @env }
    warden = ::Warden::Proxy.new(renderer_env, ::Warden::Manager.new(Rails.application))
    renderer_env["warden"] = warden
    html = renderer.render(partial: "path/to/partial")
    
    ActionCable.server.broadcast "user-#{user.id}", message_type: "example", html: html
  end
end