I don't like checkstyle because it cannot be easily applied from the
commandline. I'm happy to learn otherwise, though. And I'd also be very
happy about alternative suggestions that can do that.
Right now, I think Spotless is the most straightforward tool for that.
Also I don't care so much about what style we choose in the end. (If we
choose one). My main motivation is that we have a common, strict style
that can easily applied via tooling so that we no longer need to comment
on coding style in PRs.
Aljoscha
On 09.10.20 11:11, tison wrote:
+1 on locking on one codestyle and I think that is what current checkstyle
rules serving.
For automatic applying part, we suggest developing by IDEA and with
Checkstyle Plugin on IDEA applying checkstyle suggestion is also automatic.
One short coming for spotless is that we can hardly adjust rules if the
project has its own issues to overcome. IIRC only several pre-defined rules
and a clumsy general regex substitution rule can be used.
FYI my team started with spotless but ended up with checkstyle with few
rules and Checkstyle Plugin for automation.
Codestyle, in another perspective, is part of cognition of developers
working in project, not something we just apply before pull request. No
matter how much automation introduced, most of developers will converge
working with the configured codestyle.
Best,
tison.
Kostas Kloudas <kklou...@gmail.com> 于2020年10月7日周三 下午6:37写道：
Hi all,
+1 for enforcing "a" codestyle using "a" tool.
As the project grows both in terms of LOCs and contributors, this
becomes more and more important as it eliminates some potential points
of friction without any additional effort.
From the discussion, I am leaning towards having a single commit with
all the codestyle-related changes. This will avoid sprinkling
refactoring commits all over the place for the next year or more. But
if this is the price to pay for having consensus on a tool, then I am
ok with gradual implementation. I believe that the value added by
having an automated process of enforcing a codestyle exceeds the cost
of the nuisance of gradual refactoring.
As for the actual format, I like the google-java-format but again, if
the community agrees on a different one I would not oppose that (as
long as it does not use the same amount of indentation for method args
and method body :P).
Cheers,
Kostas
On Wed, Oct 7, 2020 at 10:26 AM Chesnay Schepler <ches...@apache.org>
wrote:
To me, ratchet seems to combine the worst aspects of both approaches.
You get disruptive changes, but only in singular files,
for something mundane as a typo fix or import change, which would be
annoying to keep separate from the actual functional changes in a PR.
On 10/7/2020 10:04 AM, Matthias Pohl wrote:
I find the ratchet feature you're suggesting interesting. But Arvid
has a
point referring to the blog post about ignoring revisions in git blame
[1].
Adding the configuration file for commits to ignore revs as proposed
in the
blog post makes it even easier. One problem I see is that this is not
supported by Github (yet?) [2] as mentioned in [1].
Considering all that I prefer applying the code style in one go. I
have no
strong opinion on what codestyle is the best.
PS: We used spotless in the project I previously worked on. It was
convenient to use.
[1]
https://www.moxio.com/blog/43/ignoring-bulk-change-commits-with-git-blame
[2]
https://github.community/t/support-ignore-revs-file-in-githubs-blame-view/3256
On Tue, Oct 6, 2020 at 6:00 PM Aljoscha Krettek <aljos...@apache.org>
wrote:
Maybe I wasn't very clear on how the ratchet works. The changes are
gradual yes, but it doesn't leave you an option: if you touch a file
you
will it will have to conform to the coding style afterwards. It's not
like the previous gradual process we had before where it would be
based
on people actively working towards a style.
That being said, I also completely like the option of just doing one
big
change commit.
Regarding actual coding styles: we're a bit limited by what tools
exist.
I like Spotless because it can be used to both check and apply a
style.
Then you need a formatter that works with Spotless and of those we
only
have the Eclipse Formatter, google-java-format, and Prettier. Prettier
is a Javascript tool that I would like to avoid. Eclipse is doable but
you need to fiddle with configuration files. I like google-java-format
because of it's take-it-or-leave-it approach. You either use the style
or you don't but it's very thorough. The downside is that it won't do
tabs-only formatting.
Best,
Aljoscha
On 06.10.20 17:43, Arvid Heise wrote:
After having written that I did a quick search, you can even use git
blame
with one big massive change commit [1], which would further help the
idea
of "just get over with it".
With that option, I'd even change all whitespaces if the community
thinks
that it's a better option (a separate discussion that I'll gladly
skip).
[1]
https://www.moxio.com/blog/43/ignoring-bulk-change-commits-with-git-blame
On Tue, Oct 6, 2020 at 5:38 PM Arvid Heise <ar...@ververica.com>
wrote:
I'm also +1 for automatically enforceable code style.
I also would just go over it as Chesnay said. While it makes some
changes
a bit harder to track (inline git blame), it's easy to skip over in
any
git
history and if it's only one massive commit, then it's also much
easier
to
ignore than many gradual changes. Further, if we just do it once,
git
blame
will quickly become more reliable again.
Btw I completely don't care about the code style as long as it plays
well
with IntelliJ (it used to be different, but things change :p).
On Tue, Oct 6, 2020 at 5:23 PM Chesnay Schepler <ches...@apache.org
wrote:
We shouldn't switch to spaces _now_; cutting this bit from your
proposal
will massively simplify things and there's hardly any value in
changing
it.
Also I'm getting rather tired of this constant idea of "gradual
application". We've been doing this for 2-3 years now since we
introduced Checkstyle and basically got nowhere. We should just
bite
the
bullet and get it over with; we could've solved this whole problem
already.
In conclusion, I'm +1 on finally locking down the codestyle and
applying
it immediately, I'm -1 on any gradual application scheme because
they
_just don't work_.
On 10/6/2020 2:15 PM, Aljoscha Krettek wrote:
Hi All,
I know I know, but please keep reading because I recently learned
about some new developments in the area of coding-style
automation.
The tool I would propose we use is Spotless
(https://github.com/diffplug/spotless). This doesn't come with a
formatter but allows using other popular formatters such as
google-java-format. The nice thing about Spotless is that it
serves as
a verifier for CI but can also apply the configured style
automatically. That is, for the programmer all she has to do is
`mvn
spotless:apply` to fix any style violations.
An interesting feature, which was (somewhat) recently added is
"ratchet"
(
https://github.com/diffplug/spotless/blob/main/plugin-maven/README.md#ratchet
).
With this, you can set up Spotless to only apply it's rules to
files
that were changed after a configured commit. This would allow a
gradual application of the new coding style instead of one big
change.
If we decide to use Spotless, we would of course also have to
decide
on a coding style. For this I would propose google-java-format,
which
the flink-statefun project uses. The main difference from our
current
"style" is that this uses spaces instead of tabs for indentation.
By
default it would be 2 spaces but it can be configured to use 4
spaces
which would make code look more or less like our current style.
There
are no more configuration knobs, so using tabs is not an option.
Finally, why should we do this? I think most engineers agree that
having a common enforced style is good to have so I only want to
highlight a few thoughts here about things we could improve:
- No more nits about coding style in reviews, this makes it
easier
for both the reviewer and developer
- No manual fixing of Checkstyle errors because Spotless can
do that
automatically
- Because Flink is such a big project little islands of coding
style
have formed between people that commonly work on components. It
can be
a nuisance when you work on a different component and then
reviewers
don't like your typical coding style. And you first have to get
used
to the slight differences in style when reading code.
There are also downsides I see in this:
- We break the history, but both "git blame" and modern
IntelliJ can
ignore whitespace when attributing changes. So for files that are
already "well" formatted not much would change.
- In the short-term it will be harder to apply changes both to
master
and one of the release-x branches because formatting will be
different. I think this is not too hard though because Spotless
can
automatically apply the style.
In summary, we would have some short-term pain with this but I
think
it would be good in the long run. What are your thoughts?
Best,
Aljoscha
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