CODEWITHSUNDEEP
rubyrack
paulorcdiniz
paulorcdiniz

Reputation: 164

Wrong number of arguments on Rack::Builder.new

I apparently have a Rack::Builder misunderstanding. Inside my config.ru file i've got:

require 'rack'
require 'rack/lobster'

class Shrimp
   SHRIMP_STRING = 'teste'

   def initialize(app)
      @app = app
   end

   def call(env)
     status, headers, response = @app.call(env)

     response_body = ""
     response.each { |part| response_body += part }
     response_body += "<pre>#{SHRIMP_STRING}</pre>"

     headers["Content-Length"] = response_body.length.to_s

    [status, headers, response_body]
  end
end

app = Rack::Builder.new do
  use Rack::Lobster
  run Shrimp.new
end

Rack::Handler::WEBrick.run app

When I do a rackup config.ru

I get a 

/home/vagrant/config.ru:7:in `initialize': wrong number of arguments (0 for 1) (ArgumentError)
from /home/vagrant/config.ru:26:in `new'

Am I missing something? According to this tutorial Rack::Builder.new only receives a block as a parameter.

EDIT: changing this line

run Shrimp.new

to:

run Shrimp

I still get a wrong number of arguments, but this time for Rack::Builder

ERROR ArgumentError: wrong number of arguments (1 for 0)
/home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:86:in `initialize'

Upvotes: 0

Views: 900

Answers (1)

Saurabh
Saurabh

Reputation: 73649

For Rack middleware, you don't need to do Shrimp.new, You just need to do use Shrimp and it should do.

You can find it's one example here.

As par this link you only need to do following:

# config.ru
require 'rack'
require 'rack/lobster'
require 'shrimp'      

use Shrimp            
run Rack::Lobster.new

Upvotes: 1

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