tests/test-extensions-wrapfunction.py

rhg: in path_encode, split Dest into VecDest and MeasureDest

Two separate types make the write semantics easier to understand
because we can consider the two sinks separately.

Having two independent compiled functions for size measurement
and for actual encoding seems likely to improve performance, too.
(and maybe we should get rid of measurement altogether)

Getting rid of [Dest] also removes the ugly option rewrapping
code, which is good.

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:
    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 is not None and 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:
    def __call__(self):
        return ['orig']


dummy.cobj = callableobj()
extensions.wrapfunction(dummy, 'cobj', wrappers[0])
print('wrap callable object', dummy.cobj())