Helper to wrap external API requests

cocoon.cr

class Cocoon(T)
  def initialize(
      @result = Channel(T | Exception).new,
      @output = Channel(T | Exception).new
    )
  end

  def wrap(&block : -> T) forall T
    spawn(name: "executor") do
      @result.send block.call
      rescue e
        @result.send e
    end

    Fiber.yield

    spawn(name: "receiver") do
      select
      when data = @result.receive
        @output.send data
      end
    end

    @output
  end
end

# -----

cocoon = Cocoon(HTTP::Client::Response).new
result = cocoon.wrap do
  HTTP::Client.get "localhost:9292"
end

result.receive
#=> <HTTP::Client::Response...>