diff --git a/letsencrypt/display/completer.py b/letsencrypt/display/completer.py new file mode 100644 index 000000000..5258ef52e --- /dev/null +++ b/letsencrypt/display/completer.py @@ -0,0 +1,51 @@ +"""Provides tab autocompletion when prompting users for a path.""" +import glob +import readline + + +class Completer(object): + """Provides tab autocompletion when prompting users for a path. + + This class is meant to be used with readline to provide tab + autocompletion for users entering paths. The complete method can + be passed to readline.set_completer directly, however, this function + works best as a context manager. For example: + + with Completer(): + raw_input() + + In this example, tab autocompletion will be available during + the call to raw_input above, however, readline will be restored to + its previous state when exiting the body of the with statement. + + """ + + def __init__(self): + self._completer = self._delims = self._iter = None + + def complete(self, text, state): + """Provides path autocompletion for use with readline. + + :param str text: text to offer completions for + :param int state: which completion to return + + :returns: possible completion for text or ``None`` if all + completions have been returned + :rtype: str + + """ + if state == 0: + self._iter = glob.iglob(text + '*') + return next(self._iter, None) + + def __enter__(self): + self._completer = readline.get_completer() + self._delims = readline.get_completer_delims() + + readline.set_completer(self.complete) + readline.set_completer_delims(' \t\n;') + readline.parse_and_bind('tab: complete') + + def __exit__(self, unused_type, unused_value, unused_traceback): + readline.set_completer_delims(self._delims) + readline.set_completer(self._completer) diff --git a/letsencrypt/tests/display/completer_test.py b/letsencrypt/tests/display/completer_test.py new file mode 100644 index 000000000..dbba15106 --- /dev/null +++ b/letsencrypt/tests/display/completer_test.py @@ -0,0 +1,64 @@ +"""Test letsencrypt.display.completer.""" +import os +import readline +import shutil +import string +import tempfile +import unittest + + +class CompleterTest(unittest.TestCase): + """Test letsencrypt.display.completer.Completer.""" + + def setUp(self): + self.temp_dir = tempfile.mkdtemp() + + # directories must end with os.sep for completer to + # search inside the directory for possible completions + if self.temp_dir[-1] != os.sep: + self.temp_dir += os.sep + + self.paths = [] + # create some files and directories in temp_dir + for c in string.ascii_lowercase: + path = os.path.join(self.temp_dir, c) + self.paths.append(path) + if ord(c) % 2: + os.mkdir(path) + else: + with open(path, 'w'): + pass + + def tearDown(self): + shutil.rmtree(self.temp_dir) + + def test_context_manager(self): + from letsencrypt.display import completer + + original_completer = readline.get_completer() + original_delims = readline.get_completer_delims() + + with completer.Completer(): + pass + + self.assertEqual(readline.get_completer(), original_completer) + self.assertEqual(readline.get_completer_delims(), original_delims) + + def test_complete(self): + from letsencrypt.display import completer + + my_completer = completer.Completer() + num_paths = len(self.paths) + + for i in range(num_paths): + completion = my_completer.complete(self.temp_dir, i) + self.assertTrue(completion in self.paths) + self.paths.remove(completion) + + self.assertFalse(self.paths) + completion = my_completer.complete(self.temp_dir, num_paths) + self.assertEqual(completion, None) + + +if __name__ == "__main__": + unittest.main() # pragma: no cover