def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def GetCompletions_Basic_test( app ):
  filepath = PathToTestFile( 'basic.py' )
  completion_data = BuildRequest( filepath = filepath,
                                  filetype = 'python',
                                  contents = ReadFile( filepath ),
                                  line_num = 7,
                                  column_num = 3)

  results = app.post_json( '/completions',
                           completion_data ).json[ 'completions' ]

  assert_that( results,
               has_items(
                 CompletionEntryMatcher( 'a' ),
                 CompletionEntryMatcher( 'b' ),
                 CompletionLocationMatcher( 'line_num', 3 ),
                 CompletionLocationMatcher( 'line_num', 4 ),
                 CompletionLocationMatcher( 'column_num', 10 ),
                 CompletionLocationMatcher( 'filepath', filepath ) ) )