Added completer.py and tests for FileDisplay

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)

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