Class ParserTesterMetaclass

Lib/test/test_argparse.py:222–335

Adds parser tests using the class attributes. Classes of this type should specify the following attributes: argument_signatures -- a list of Sig objects which specify the signatures of Argument objects to be created failures -- a list of args lists that should cause the parser

class ParserTesterMetaclass(type):
    """Adds parser tests using the class attributes.

    Classes of this type should specify the following attributes:

    argument_signatures -- a list of Sig objects which specify
        the signatures of Argument objects to be created
    failures -- a list of args lists that should cause the parser
        to fail
    successes -- a list of (initial_args, options, remaining_args) tuples
        where initial_args specifies the string args to be parsed,
        options is a dict that should match the vars() of the options
        parsed out of initial_args, and remaining_args should be any
        remaining unparsed arguments
    """

    def __init__(cls, name, bases, bodydict):
        if name == 'ParserTestCase':
            return

        # default parser signature is empty
        if not hasattr(cls, 'parser_signature'):
            cls.parser_signature = Sig()
        if not hasattr(cls, 'parser_class'):
            cls.parser_class = ErrorRaisingArgumentParser

        # ---------------------------------------
        # functions for adding optional arguments
        # ---------------------------------------
        def no_groups(parser, argument_signatures):
            """Add all arguments directly to the parser"""
            for sig in argument_signatures:
                parser.add_argument(*sig.args, **sig.kwargs)

        def one_group(parser, argument_signatures):
            """Add all arguments under a single group in the parser"""
            group = parser.add_argument_group('foo')
            for sig in argument_signatures:
                group.add_argument(*sig.args, **sig.kwargs)

        def many_groups(parser, argument_signatures):
            """Add each argument in its own group to the parser"""
            for i, sig in enumerate(argument_signatures):
                group = parser.add_argument_group('foo:%i' % i)
                group.add_argument(*sig.args, **sig.kwargs)

        # --------------------------
        # functions for parsing args
        # --------------------------
        def listargs(parser, args):
            """Parse the args by passing in a list"""
            return parser.parse_args(args)

        def sysargs(parser, args):
            """Parse the args by defaulting to sys.argv"""
            old_sys_argv = sys.argv
            sys.argv = [old_sys_argv[0]] + args
            try: