diff options
| -rw-r--r-- | cmd2/parsing.py | 99 | ||||
| -rw-r--r-- | tests/test_parsing.py | 16 |
2 files changed, 55 insertions, 60 deletions
diff --git a/cmd2/parsing.py b/cmd2/parsing.py index 553c5b9a..a5dbb72c 100644 --- a/cmd2/parsing.py +++ b/cmd2/parsing.py @@ -7,10 +7,13 @@ import re import shlex from typing import List, Tuple, Dict +import attr + from . import constants from . import utils +@attr.s(frozen=True) class Statement(str): """String subclass with additional attributes to store the results of parsing. @@ -26,9 +29,38 @@ class Statement(str): The string portion of the class contains the arguments, but not the command, nor the output redirection clauses. """ + # the arguments, but not the command, nor the output redirection clauses. + args = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # string containing exactly what we input by the user + raw = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # the command, i.e. the first whitespace delimited word + command = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # list of arguments to the command, not including any output redirection or terminators; quoted args remain quoted + arg_list = attr.ib(factory=list, validator=attr.validators.instance_of(list), type=List[str]) + + # if the command is a multiline command, the name of the command, otherwise empty + multiline_command = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # the character which terminated the multiline command, if there was one + terminator = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # characters appearing after the terminator but before output redirection, if any + suffix = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # if output was piped to a shell command, the shell command as a list of tokens + pipe_to = attr.ib(factory=list, validator=attr.validators.instance_of(list), type=List[str]) + + # if output was redirected, the redirection token, i.e. '>>' + output = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + + # if output was redirected, the destination file + output_to = attr.ib(default='', validator=attr.validators.instance_of(str), type=str) + def __new__(cls, - obj: object, - *, + args: object, raw: str = '', command: str = '', arg_list: List[str] = None, @@ -39,49 +71,14 @@ class Statement(str): output: str = '', output_to: str = '' ): - """ - :param value: The arguments, but not the command, nor the output redirection clauses. - :param raw: string containing exactly what we input by the user - :param command: the command, i.e. the first whitespace delimited word - :param arg_list: list of arguments to the command, not including any output - redirection or terminators. quoted arguments remain quoted. - :param multiline_command: if the command is a multiline command, the name of the - command, otherwise empty - :param terminator: the character which terminated the multiline command, if - there was one - :param suffix: characters appearing after the terminator but before output redirection, if any - :param pipe_to: if output was piped to a shell command, the shell command as a list of tokens - :param output: if output was redirected, the redirection token, i.e. '>>' - :param output_to: if output was redirected, the destination file - """ - """Create a new instance of Statement - - We must override __new__ because we are subclassing `str` which is - immutable. - """ - stmt = super().__new__(cls, obj) - stmt.raw = raw - stmt.command = command - - if arg_list is None: - arg_list = [] - stmt.arg_list = arg_list + """Create a new instance of Statement. - stmt.multiline_command = multiline_command - stmt.terminator = terminator - stmt.suffix = suffix - - if pipe_to is None: - pipe_to = [] - stmt.pipe_to = pipe_to - - stmt.output = output - stmt.output_to = output_to - - # Make Statement feel immutable by overriding these functions - stmt.__setattr__ = stmt.__stmt_setattr__ - stmt.__delattr__ = stmt.__stmt_delattr__ + We must override __new__ because we are subclassing `str` which is immutable and takes a different number of + arguments as Statement. + NOTE: attrs takes care of initializing other members in the __init__ it generates. + """ + stmt = super().__new__(cls, args) return stmt @property @@ -100,14 +97,6 @@ class Statement(str): return rtn @property - def args(self) -> str: - """the arguments to the command, not including any output redirection or terminators. - - Quoted arguments remain quoted. - """ - return str(self) - - @property def argv(self) -> List[str]: """a list of arguments a la sys.argv. Quotes, if any, are removed from the elements of the list, and aliases and shortcuts are expanded @@ -121,14 +110,6 @@ class Statement(str): return rtn - def __stmt_setattr__(self, name, value): - """Statement instances should feel immutable; raise ValueError""" - raise ValueError - - def __stmt_delattr__(self, name): - """Statement instances should feel immutable; raise ValueError""" - raise ValueError - class StatementParser: """Parse raw text into command components. diff --git a/tests/test_parsing.py b/tests/test_parsing.py index da1fcb4d..b4de88ad 100644 --- a/tests/test_parsing.py +++ b/tests/test_parsing.py @@ -5,6 +5,7 @@ Test the parsing logic in parsing.py Copyright 2017 Todd Leonhardt <todd.leonhardt@gmail.com> Released under MIT license, see LICENSE file """ +import attr import pytest import cmd2 @@ -639,7 +640,8 @@ def test_parse_command_only_multiline(parser): assert statement.command_and_args == line assert statement.args == statement -def test_statement_initialization(parser): + +def test_statement_initialization(): string = 'alias' statement = cmd2.Statement(string) assert string == statement @@ -657,3 +659,15 @@ def test_statement_initialization(parser): assert not statement.pipe_to assert statement.output == '' assert statement.output_to == '' + + +def test_statement_is_immutable(): + string = 'foo' + statement = cmd2.Statement(string) + assert string == statement + assert statement.args == statement + assert statement.raw == '' + with pytest.raises(attr.exceptions.FrozenInstanceError): + statement.args = 'bar' + with pytest.raises(attr.exceptions.FrozenInstanceError): + statement.raw = 'baz' |