Monkey patching injector decorators.

injector.py

# Copyright 2017 Daniel Hilst Selli, <danielhilst@gmail.com> 
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from importlib import import_module

def inject_func(target):
    def decorator(func):
        module_spec, target_func = target.rsplit('.', 1)
        module = import_module(module_spec)
        func.target = getattr(module, target_func)
        setattr(module, target_func, func)
        return func
    return decorator

def inject_class(target):
    def decorator(proxy_cls):
        module_spec, target_spec = target.rsplit('.', 1)
        module = import_module(module_spec)
        target_cls = getattr(module, target_spec)
        proxyobj = type(target_cls.__name__, (proxy_cls, target_cls), {'_target': target_cls})
        setattr(module, target_spec, proxyobj)
        return proxyobj
    return decorator