How to start and stop Puma programmatically (e.g. from a test)

test_puma_runs.rb

# inspiration -> the puma tests
require 'puma'
require 'puma/server'

def with_puma_running(app)
  server = Puma::Server.new(app, Puma::Events.strings)
  server.add_tcp_listener "127.0.0.1", 0
  server.run
  port = server.connected_port
  yield(port: port)
ensure
  server&.stop(true)
end

app = proc do |env|
  [ 200, {"Content-Type" => "text/html"}, ["OK"] ]
end

with_puma_running(app) do |port:|
  # SNIP
end