A Rack 3 example of bidirectional streaming with Async HTTP

client.rb

# frozen_string_literal: true

require 'async/http/internet'

Async do
  internet = Async::HTTP::Internet.new
  response = internet.get('http://localhost:9292')

  stream = response.connection.stream
  stream.write('Hello World!')
  stream.close_write

  puts response.read
end

config.ru

# frozen_string_literal: true

def headers = {'content-type' => 'text/plain'}
  
STREAM = -> do 
  _1.write _1.read
ensure
  _1.close
end

run do |_env|
  [200, headers, STREAM]
end