Hi all, I've just released Coverage.py 4.1 beta 1: http://nedbatchelder.com/blog/201601/coveragepy_41b1.html
It has a new branch analysis implementation, partly to deal with the async keyword. But I need some help deciding how it should work with the new features. A yield-from statement is possibly an exit from the function, as it yields values. If you use a yield-from, and no values are yielded, coverage.py 4.1b1 will mark it as partially uncovered because the branch to the function exit isn't taken. But yield-from is also used to call functions that won't produce a value. 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. What would you prefer? My understanding is that "await" behaves the same, so I'm assuming the same decision would apply there. BTW: the 4.1b1 code is definitely wrong in that it doesn't grok the difference between "yield from x" and "v = yield from x". The latter is clearly not a function exit, but 4.1b1 also insists that it should branch to the function exit, which it never will, so at the very least that has to get fixed. Any other thoughts about what's needed are also welcome. Thanks, --Ned.
