module Tapioca::Helpers::Test::Isolation::Subprocess

def run_in_isolation(&_blk)
  this = T.cast(self, Minitest::Test)
  require "tempfile"
  if ENV["ISOLATION_TEST"]
    yield
    test_result = defined?(Minitest::Result) ? Minitest::Result.from(self) : this.dup
    File.open(T.must(ENV["ISOLATION_OUTPUT"]), "w") do |file|
      file.puts [Marshal.dump(test_result)].pack("m")
    end
    exit!(false)
  else
    Tempfile.open("isolation") do |tmpfile|
      env = {
        "ISOLATION_TEST" => this.class.name,
        "ISOLATION_OUTPUT" => tmpfile.path,
      }
      test_opts = "-n#{this.class.name}##{this.name}"
      load_path_args = []
      $-I.each do |p|
        load_path_args << "-I"
        load_path_args << File.expand_path(p)
      end
      child = IO.popen([env, ::Gem.ruby, *load_path_args, $PROGRAM_NAME, *ORIG_ARGV, test_opts])
      begin
        Process.wait(child.pid)
      rescue Errno::ECHILD # The child process may exit before we wait
        nil
      end
      return T.must(tmpfile.read).unpack1("m")
    end
  end
end