am not able to setup the OmniAuth strategy

[deepak]

I am trying to setup like so:

AUTH0_SETUP = lambda do |env|
  req = Rack::Request.new(env)

  namespace = 'foobar.auth0.com'
  site = "https://#{namespace}"
  client_info_querystring = "..."

  env['omniauth.strategy'].options[:client_id] = 'some-id'
  env['omniauth.strategy'].options[:client_secret] = 'some-secret'
  env['omniauth.strategy'].options[:namespace] = namespace
  env['omniauth.strategy'].options[:provider_ignores_state] = { callback_path: "/auth/auth0/callback" }
  env['omniauth.strategy'].options[:client_options]
    .merge!(site: site,
      authorize_url: "#{site}/authorize?#{client_info_querystring}",
      token_url: "#{site}/oauth/token?#{client_info_querystring}",
      userinfo_url: "#{site}/userinfo")
end

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :auth0, setup: AUTH0_SETUP
end

but this does not work because OmniAuth::Strategies::Auth0::initialize depends on args
and has a check on argument

fail(ArgumentError.new("Received wrong number of arguments. #{args.inspect}")) if @options[: namespace].nil?

but in case of setup args will be [{setup: <Proc>}] and will not have the namespace it needs

other Omniauth strategies like facebook use the option class method to configure it
and do not use the initialize method