view tests/test-extensions-wrapfunction.py @ 36411:38f480502043

context: remove basectx.__int__ (API)

basectx is the only type in the repo having __int__ implemented.

This magic method can result in unexpected coercion. Furthermore,
having it implemented is wrong for some contexts, since rev() may
return None in some cases.

Previous commits removed known cases in core where contexts are
coerced to integers. So let's delete basectx.__int__.

This commit is a bit dangerous. While the test suite passes, there
are likely still some callers in core that rely on __int__ that
don't have test coverage. An alternative would be to issue a
deprecation warning and let this bake for a few releases.

.. api::

   context.basectx no longer implements __int__. Context instances
   will no longer cast to ints. Consumers should call ``ctx.rev()``
   instead.

Differential Revision: https://phab.mercurial-scm.org/D2433

from __future__ import absolute_import, print_function

from mercurial import extensions

def genwrapper(x):
    def f(orig, *args, **kwds):
        return [x] + orig(*args, **kwds)
    f.x = x
    return f

def getid(wrapper):
    return getattr(wrapper, 'x', '-')

wrappers = [genwrapper(i) for i in range(5)]

class dummyclass(object):
    def getstack(self):
        return ['orig']

dummy = dummyclass()

def batchwrap(wrappers):
    for w in wrappers:
        extensions.wrapfunction(dummy, 'getstack', w)
        print('wrap %d: %s' % (getid(w), dummy.getstack()))

def batchunwrap(wrappers):
    for w in wrappers:
        result = None
        try:
            result = extensions.unwrapfunction(dummy, 'getstack', w)
            msg = str(dummy.getstack())
        except (ValueError, IndexError) as e:
            msg = e.__class__.__name__
        print('unwrap %s: %s: %s' % (getid(w), getid(result), msg))

batchwrap(wrappers + [wrappers[0]])
batchunwrap([(wrappers[i] if i >= 0 else None)
             for i in [3, None, 0, 4, 0, 2, 1, None]])

wrap0 = extensions.wrappedfunction(dummy, 'getstack', wrappers[0])
wrap1 = extensions.wrappedfunction(dummy, 'getstack', wrappers[1])

# Use them in a different order from how they were created to check that
# the wrapping happens in __enter__, not in __init__
print('context manager', dummy.getstack())
with wrap1:
    print('context manager', dummy.getstack())
    with wrap0:
        print('context manager', dummy.getstack())
        # Bad programmer forgets to unwrap the function, but the context
        # managers still unwrap their wrappings.
        extensions.wrapfunction(dummy, 'getstack', wrappers[2])
        print('context manager', dummy.getstack())
    print('context manager', dummy.getstack())
print('context manager', dummy.getstack())

# Wrap callable object which has no __name__
class callableobj(object):
    def __call__(self):
        return ['orig']
dummy.cobj = callableobj()
extensions.wrapfunction(dummy, 'cobj', wrappers[0])
print('wrap callable object', dummy.cobj())