Puma worker config breaks spring reloading for helpers

[rafaelfranca]

From @jeroenvisser101 on April 4, 2016 14:41

Steps to reproduce

1. rails new <app name>
2. rails g controller Home index
3. Edit config/puma.rb to use workers, without that, the bug doesn't occur
4. Create a dummy helper and use it in the view
5. rails server
6. Edit the helper
7. Refresh

A minimal example can be found here

Expected behavior

The result should change because Spring should reload the app.

Actual behavior

Spring doesn't reload the app, old version is executed instead.

System configuration

Rails version: 5.0.0.beta3
Ruby version: 2.3.0-p0
Puma version: 3.2.0

Copied from original issue: rails/rails#24414

[rafaelfranca]

Spring is expecting that you application have only one process so I'm not sure if this is a bug or a limitation of spring. Either way I'm moving this issue to the spring repository.

[jeroenvisser101]

@rafaelfranca thanks for your quick reply – I'm not sure about the internals of Spring, but we might want to address this in the documentation (or in the config/puma.rb file, in the part that discribes the worker config), if this is a limitation of what Spring can do.

This seems to affect me as well, is a workaround to default your workers to one in development, workers Integer(ENV['WEB_CONCURRENCY'] || 1) ? Err-- this doesn't appear to fix the issue from my tests.

[jeroenvisser101]

I have this in puma.rb:

# Production settings need to be in this block
unless ENV.fetch("RAILS_ENV") { "development" } == "development"
  workers ENV.fetch("WEB_CONCURRENCY") { 2 }
  preload_app!

  on_worker_boot do
    ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
  end
end