view tests/test-ctxmanager.py @ 31990:3e03a4b9ec8c

windows: add win32com.shell to demandimport ignore list

Module 'appdirs' tries to import win32com.shell (and catch ImportError as an
indication of failure) to check whether some further functionality should
be implemented one or another way [1]. Of course, demandimport lets it down, so
if we want appdirs to work we have to add it to demandimport's ignore list.

The reason we want appdirs to work is becuase it is used by setuptools [2] to
determine egg cache location. Only fairly recent versions of setuptools depend
on this so people don't see this often.


[1] https://github.com/ActiveState/appdirs/blob/master/appdirs.py#L560
[2] https://github.com/pypa/setuptools/blob/aae0a928119d2a178882c32bded02270e30d0273/pkg_resources/__init__.py#L1369

from __future__ import absolute_import

import silenttestrunner
import unittest

from mercurial import util

class contextmanager(object):
    def __init__(self, name, trace):
        self.name = name
        self.entered = False
        self.exited = False
        self.trace = trace

    def __enter__(self):
        self.entered = True
        self.trace(('enter', self.name))
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.exited = exc_type, exc_val, exc_tb
        self.trace(('exit', self.name))

    def __repr__(self):
        return '<ctx %r>' % self.name

class ctxerror(Exception):
    pass

class raise_on_enter(contextmanager):
    def __enter__(self):
        self.trace(('raise', self.name))
        raise ctxerror(self.name)

class raise_on_exit(contextmanager):
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.trace(('raise', self.name))
        raise ctxerror(self.name)

def ctxmgr(name, trace):
    return lambda: contextmanager(name, trace)

class test_ctxmanager(unittest.TestCase):
    def test_basics(self):
        trace = []
        addtrace = trace.append
        with util.ctxmanager(ctxmgr('a', addtrace), ctxmgr('b', addtrace)) as c:
            a, b = c.enter()
            c.atexit(addtrace, ('atexit', 'x'))
            c.atexit(addtrace, ('atexit', 'y'))
        self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'),
                                 ('atexit', 'y'), ('atexit', 'x'),
                                 ('exit', 'b'), ('exit', 'a')])

    def test_raise_on_enter(self):
        trace = []
        addtrace = trace.append
        def go():
            with util.ctxmanager(ctxmgr('a', addtrace),
                                 lambda: raise_on_enter('b', addtrace)) as c:
                c.enter()
                addtrace('unreachable')
        self.assertRaises(ctxerror, go)
        self.assertEqual(trace, [('enter', 'a'), ('raise', 'b'), ('exit', 'a')])

    def test_raise_on_exit(self):
        trace = []
        addtrace = trace.append
        def go():
            with util.ctxmanager(ctxmgr('a', addtrace),
                                 lambda: raise_on_exit('b', addtrace)) as c:
                c.enter()
                addtrace('running')
        self.assertRaises(ctxerror, go)
        self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), 'running',
                                 ('raise', 'b'), ('exit', 'a')])

if __name__ == '__main__':
    silenttestrunner.main(__name__)