FWIW, I've just posted coverage.py 4.1b2, which no longer treats await or yield-from as an exit from the function: https://pypi.python.org/pypi/coverage/4.1b2
Any feedback appreciated :) --Ned. On Tuesday, January 12, 2016 at 3:20:08 AM UTC-5, Aymeric Augustin wrote: > > Hello Ned, > > On 12 janv. 2016, at 01:39, Ned Batchelder <[email protected] > <javascript:>> wrote: > > > So we have a choice: Should coverage.py could insist on a branch to the > function exit? Pro: this could alert you to code you thought produced > values, but doesn't. Con: the places you know you aren't getting any > values, you'll have to use a pragma comment to shut up coverage.py. > > > For developers who are only using `yield from` in the context of asyncio, > this question is equivalent to: “should coverage.py mark a branch as not > covered if a function never returns a result?”. The answer to that is “no”. > > For developers who are using `yield from` to simplify passing values from > iterators across function call chains, there’s a good chance that something > at one end of the chain will have an uncovered branch if no value is > yielded. > > As a consequence, I believe the practical policy for coverage.py is to > ignore the function exit branch in `yield from`. > > If you wanted to be really smart, you could try to tell apart `yield from > generator` from `yield from coroutine`. As of Python 3.5, you could look at > the CO_COROUTINE flag ( > https://www.python.org/dev/peps/pep-0492/#coroutine-objects). > Unfortunately, it looks like this doesn't works for pre-3.5 coroutines > decorated with @asyncio.coroutine — which is the only option for asyncio > libraries that wish to support Python 3.4 and 3.3. > > -- > Aymeric. > >
