Source code for flake8_integration.integrated

#-*- coding: utf8 -*-

"""Module used to manage the results of flake8 :

> 1. get them instead of print them ;
> 2. format them ;

This module works with Python2 and Python3

:author: Sébastien CHAZALLET <s.chazallet@gmail.com>
:organization: InsPyration EURL
:copyright: Copyright © InsPyration EURL <www.inspyration.org>
:license: GPL 3 <http://www.gnu.org/licenses/gpl.html>

:version: 0.1
"""


import sys
if sys.version_info.major == 2:
    from io import BytesIO as IO
else:
    from io import StringIO as IO

from flake8.main import check_code


def _intercept_printed(action, *args, **kwargs):
    """Function used to redirect printed to returned value

    :type  action: function
    :param action: Called function that we intercept prints

    :rtype:  str
    :return: all that was printed by the call of action

    >>> def do():
    ...     print('Hello World')
    ...
    >>> result = _intercept_printed(do)
    >>> print(result)
    Hello World
    <BLANKLINE>
    """
    with IO() as buff:
        out, sys.stdout = sys.stdout, buff
        action(*args, **kwargs)
        sys.stdout = out
        buff.seek(0)
        return buff.read()


def _format_flake8_results(warnings):
    """Function used to extract useful informations from flake8 results

    :type  warnings: str
    :param warnings: Warnings generated by flake8

    :rtype:  list
    :return: list of (code:str, line:int, col:int, description:str)

    >>> result = _format_flake8_results(
    ...     '''stdin:1:10: E901 SyntaxError: unexpected EOF while parsing
    ...     stdin:2:1: E901 TokenError: EOF in multi-line statement''')
    >>> for r in result:
    ...     print r
    ...
    (' e901', 1, 10, 'SyntaxError: unexpected EOF while parsing')
    (' e901', 2, 1, 'TokenError: EOF in multi-line statement')
    """
    result = []
    for warning in warnings.splitlines():
        cols = warning.split(':')
        result.append((cols[3][:5].lower(),
                       int(cols[1]),
                       int(cols[2]),
                       cols[3][6:] + ':' + ':'.join(cols[4:])))
    return result


def check_code_and_get_formated_result(code, ignore=(), complexity=-1):
    """Function used to return the printed result of flake8 check_code function

    >>> result = check_code_with_flake8("a = 42")
    >>> print(result)
    <BLANKLINE>
    >>> result = check_code_with_flake8("a = f(42")
    >>> print(result)
    stdin:1:10: E901 SyntaxError: unexpected EOF while parsing
    stdin:2:1: E901 TokenError: EOF in multi-line statement
    <BLANKLINE>
    """
    return _format_flake8_results(
        _intercept_printed(
            check_code,
            **{"code": code, "ignore": ignore, "complexity": complexity}))


if __name__ == '__main__':
    import doctest
    doctest.testmod()