Reload Grape API in Dev Env.rb

INSPIRATION: https://github.com/intridea/grape/issues/131#issuecomment-10413342

File: config/application.rb

config.autoload_paths += %W(#{config.root}/app/api #{config.root}/app/api/*/*)


File: config/environments/development.rb

# Add below code before DummyApp::Application.configure BLOCK

@last_api_change = Time.now
api_reloader = ActiveSupport::FileUpdateChecker.new(Dir["#{Rails.root}/app/api/**/*.rb"]) do |reloader|
  times = Dir["#{Rails.root}/app/api/**/*.rb"].map{|f| File.mtime(f) }
  files = Dir["#{Rails.root}/app/api/**/*.rb"].map{|f| f }

  Rails.logger.debug "! Change detected: reloading following files:"
  files.each_with_index do |s,i|
    if times[i] > @last_api_change
      Rails.logger.debug " - #{s}"
#      load s
      require_dependency s  
    end
  end

  Rails.application.reload_routes!
  Rails.application.routes_reloader.reload!
  Rails.application.eager_load!
end

ActionDispatch::Reloader.to_prepare do
  api_reloader.execute_if_updated
end

FILE: config/routes.rb

# Use require_dependency instead of require to include the Grape Api file

require_dependency 'module_name(as in your application)/grape_api_file_name'

NOTE: To be on safer side, I used require_dependency to load grape too in grape_api_file_name.

FILE: app/api/module_name/grape_api_file_name.rb
require_dependency 'grape'