[eesmith]

None of your comments mention running the full test suite, only build.

When I've used bisection, I've always had a targeted test that I was trying to fail, not the entire test suite. This is because the test suite at the time of that commit wasn't good enough to detect this failure. Otherwise it would have failed with that commit.

Instead, a new failure mode is detected, an automated test developed, and that used to probe the history to identify the commit.

Why are your bisections doing the full suite?

> Black reformatting causes more steps in bisecting

Yes, of course it does. But it's log2(n).

The worst-case analysis I did assumed there was a black commit after every human commit. This is a bad practice. You should be using black as a pre-commit hook, in which case only your new collaborator's commits will cause re-formats. And once they are onboard, you can explain how to use requirements.txt in a virtualenv.

If only 10% of the commits are black reformattings, which is still high!, then a bisection of 100 human commits (plus 10 black commits) goes from about 6.64 tests to 6.78 tests, which with a 5 minute test suite takes an additional 42 seconds.

If it's 3% then your bisection time goes up by 13 seconds.

If you are so worried about 13 seconds per bisection then how much time have you spent reducing the 5 minute test suite time? I presume you run your test suite before every commit, yes? Because if not, and you're letting CI run the test suite, then you're likely introducing more commits to fix breaking tests than you would have added via black, and taking the mental task switch hit of losing then regaining focus.

[bombolo]

> This is a bad practice. You should be using black as a pre-commit hook

I would reject such commits in review.

A human might add one or two items to a list and black might decide it's now too long, and make 1 line into 10 lines.

Now I have to manually compare the list item by item to figure out what has changed.

So I normally require formatting to be done in a separate commit, because I don't want to review the larger than necessary diffs that come out doing it within the same commit.

[eesmith]

> A human might add one or two items to a list and black might decide it's now too long, and make 1 line into 10 lines.

A human might add one or two items to a list, decide it's now too long, and make 1 line into 10 lines.

Including the same hypothetical first contributor you mentioned earlier, who you think will find using requirements.txt as being too big a barrier to entry.

Onboarding occurs either way.

I get that you don't like using black - and that's fine! I don't use black on my project either.

But it seems like you're trying to find some other reason to reject black, and constructing hypotheticals that don't make any sense.

Just say you don't like black's choices, and leave it at that.

[bombolo]

> A human might add one or two items to a list, decide it's now too long, and make 1 line into 10 lines.

At which point I tell him to split formatting and actual changes into different commits (see https://mtlynch.io/code-review-love/).

> I get that you don't like using black - and that's fine! I don't use black on my project either.

Well according to this comment, it's because we are noobs: "the people that disagree just haven't figured out that they're wrong yet"

> But it seems like you're trying to find some other reason to reject black, and constructing hypotheticals that don't make any sense.

After the n-th time I have to re-setup the entire virtual env on a different branch just to re-run black and isort to backport a fix to a release branch… it does get tiring.

I presume most people here just do websites and don't really have a product that is released to customers who pay to support old versions for years, so black changing syntax is a 1 time event rather than a continuous source of daily pain.

But it seems the commentators here don't have the experience to know there might be a use case they didn't think of.

[eesmith]

> and don't really have a product that is released to customers who pay to support old versions for years

My main product is 12 years old, with paying support customers, and with bugfix branches for older releases.

> just to re-run black and isort to backport a fix to a release branch

Great! That's an excellent reason. But it has nothing to with bisection.