feat: support running the puma plugin in a bare puma process

that is, not in `rails server`.

Closes #458

CHANGELOG.md

@@ -1,5 +1,10 @@
 ## next / unreleased
 
+## v3.3.0 / unreleased
+
+* Add support for running the puma plugin outside of `rails server`. (#458) @flavorjones
+
+
 ## v3.2.0 / 2025-01-10
 
 * Improve the scaffold views by making positions, padding, and sizes more consistent, add titles to all pages, add hover states and semantic colors to buttons and links, and change border and focus colors on fields with errors. (#452) @patriciomacadden

README.md

@@ -118,13 +118,14 @@ While you're developing your application, you want to run Tailwind in "watch" mo
 
 #### Puma plugin
 
-This gem ships with a Puma plugin. To use it, add this line to your `puma.rb` configuration:
+This gem ships with a Puma plugin. To use it, add this to your `puma.rb` configuration:
 
 ```ruby
+require_relative "application"
 plugin :tailwindcss if ENV.fetch("RAILS_ENV", "development") == "development"
 ```
 
-and then running `rails server` will run the Tailwind watch process in the background
+and then running `rails server` (or just `puma`) will run the Tailwind watch process in the background.
 
 
 #### Run `rails tailwindcss:watch`

lib/puma/plugin/tailwindcss.rb

@@ -1,4 +1,5 @@
 require "puma/plugin"
+require "tailwindcss/commands"
 
 Puma::Plugin.create do
   attr_reader :puma_pid, :tailwind_pid, :log_writer
@@ -11,8 +12,11 @@ def start(launcher)
       # Using IO.popen(command, 'r+') will avoid watch_command read from $stdin.
       # If we use system(*command) instead, IRB and Debug can't read from $stdin
       # correctly bacause some keystrokes will be taken by watch_command.
-      IO.popen(Tailwindcss::Commands.watch_command, 'r+') do |io|
-        IO.copy_stream(io, $stdout)
+      begin
+        IO.popen(Tailwindcss::Commands.watch_command, 'r+') do |io|
+          IO.copy_stream(io, $stdout)
+        end
+      rescue Interrupt
       end
     end