As a (mainly) Python dev, I'm aware that there are DI frameworks out there, but personally I haven't to date used any of them.
My favourite little hack for simple framework-less DI in Python these days looks something like this:
# The code that we want to call
def do_foo(sleep_func = None):
_sleep_func = sleep_func if sleep_func is not None else time.sleep
for _ in range(10):
_sleep_func(1)
# Calling it in non-test code
# (we want it to actually take 10 seconds to run)
def main():
do_foo()
# Calling it in test code
# (we want it to take mere milliseconds to run, but nevertheless we
# want to test that it sleeps 10 times!)
def test_do_foo():
mock_sleep_func = MagicMock()
do_foo(sleep_func=mock_sleep_func)
assert mock_sleep_func.call_count == 10Yeah, I use this sometimes too (even though Python makes "monkey patching" easy). However, note that it's simpler and clearer to use a default value for the argument:
def do_foo(sleep=time.sleep):
for _ in range(10):
sleep(1)
[1] https://en.wikipedia.org/wiki/Go_(game)