"""Shared testing utilities."""


class _Monkey(object):
    # context-manager for replacing module names in the scope of a test.

    def __init__(self, module, **kw):
        self.module = module
        self.to_restore = dict([(key, getattr(module, key)) for key in kw])
        for key, value in kw.items():
            setattr(module, key, value)

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        for key, value in self.to_restore.items():
            setattr(self.module, key, value)