dev-server.rb

#!/usr/bin/env ruby
# Stakeout inspired, Hacked from benschwarz's watch
# Will restart node if any .js files in or below this folder change. Will also restart
# if node exits (with protection to avoid rapid exit loops)
# Assumes your main script is called server.js . 
    
def start_node
  puts "\n** Node Started **\n"
  @node_pid = Kernel.fork { exec "node server.js" }
end

def file_list
  Dir[@path].map {|file| File.mtime(file) }
end

start_node

@path = ::File.join(::File.expand_path(::File.dirname(__FILE__)), '**/*.js')
@files = file_list
@last_run_exited = false

loop do
  sleep 0.5
  if file_list != @files
    @files = file_list
    puts "\n** Restarting node **\n"
    Process.kill("INT", @node_pid)
    start_node
  end
  # Check if node has died, if so restart. 
  begin
    Process.getpgid(@node_pid)
    @last_run_exited = false
  rescue
    # only auto-restart if the last loop wasn't in error
    if @last_run_exited
      puts "\n** Node exited repeatedly, slowing restart **\n"
      sleep 4.5
    else
      puts "\n** Node exited, restarting **\n"
    end
    start_node
    @last_run_exited = true
  end
end