def build_completion(opt_parser):
    commands = []

    for group in opt_parser.option_groups:
        for option in group.option_list:
            long_option = option.get_opt_string().strip('-')
            help_msg = shell_quote([option.help])
            complete_cmd = ['complete', '--command', 'youtube-dl', '--long-option', long_option]
            if option._short_opts:
                complete_cmd += ['--short-option', option._short_opts[0].strip('-')]
            if option.help != optparse.SUPPRESS_HELP:
                complete_cmd += ['--description', option.help]
            complete_cmd.extend(EXTRA_ARGS.get(long_option, []))
            commands.append(shell_quote(complete_cmd))

    with open(FISH_COMPLETION_TEMPLATE) as f:
        template = f.read()
    filled_template = template.replace('{{commands}}', '\n'.join(commands))
    with open(FISH_COMPLETION_FILE, 'w') as f:
        f.write(filled_template)

 def test_shell_quote(self):
     args = ['ffmpeg', '-i', encodeFilename('ñ€ß\'.mp4')]
     self.assertEqual(shell_quote(args), """ffmpeg -i 'ñ€ß'"'"'.mp4'""")

 def test_shell_quote(self):
     args = ["ffmpeg", "-i", encodeFilename("ñ€ß'.mp4")]
     self.assertEqual(shell_quote(args), """ffmpeg -i 'ñ€ß'"'"'.mp4'""")