"""
This plugin installs a SKIP error class for the SkipTest exception.
When SkipTest is raised, the exception will be logged in the skipped
attribute of the result, 'S' or 'SKIP' (verbose) will be output, and
the exception will not be counted as an error or failure. This plugin
is enabled by default but may be disabled with the --no-skip option.
"""
    
import os
from nose.plugins.errorclass import ErrorClass, ErrorClassPlugin


class SkipTest(Exception):
    """Raise this exception to mark a test as skipped.
    """
    pass


class Skip(ErrorClassPlugin):
    """
    Plugin that installs a SKIP error class for the SkipTest
    exception.  When SkipTest is raised, the exception will be logged
    in the skipped attribute of the result, 'S' or 'SKIP' (verbose)
    will be output, and the exception will not be counted as an error
    or failure.
    """
    enabled = True
    skipped = ErrorClass(SkipTest,
                         label='SKIP',
                         isfailure=False)

    def options(self, parser, env=os.environ):
        env_opt = 'NOSE_WITHOUT_SKIP'
        parser.add_option('--no-skip', action='store_true',
                          dest='noSkip', default=env.get(env_opt, False),
                          help="Disable special handling of SkipTest "
                          "exceptions.")

    def configure(self, options, conf):
        if not self.can_configure:
            return
        self.conf = conf
        disable = getattr(options, 'noSkip', False)
        if disable:
            self.enabled = False