Sinatra validations

require "sinatra/validations"

class Api < Sinatra::Base
  helpers Sinatra::Validations

  get "/users" do
    validate params, :sort, type: String, default: "desc"
    validate params, :limit, type: Integer, default: 30
    validate params, :filter_by, type: String, default: nil

    # ...
  end

  get "/users/:user" do
    validate params, :user, type: String

    # ...
  end
end