LineLength Max: 120?

[jnebeker]

Just wanted to open this issue for discussion. Currently, the common rubocop configuration sticks to the default Metrics/LineLength constraint of 80 characters. Previously in donkeykong we had a higher limit of 120 characters:

Metrics/LineLength:
  Max: 120

I'm not sure how strongly people feel about this, I know that the style guide has the 80 character limit, and some other style guides suggest a 100 character limit.

Do we want to stick to the default 80 character limit or increase it to something like 100 or 120?

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For context on how some of our apps currently align to the constraints, I ran rubocup on different apps with the 80 character limit and 120 character limit:

App	80 char. offenses	120 char. offenses
captain_crook	349	64
hamburglar	219	13
donkeykong	191	6
gossamer	427	24
kronos	444	76
kracken	246	22
sauron	:scream: 0 👏	0

After seeing what @cupakromer has done with sauron I'm not even sure I want to switch to the 120 limit anymore. Instead we could keep the default 80 character limit as a constant reminder to strive for greatness.

[cupakromer]

I extracted a few more settings from the project in #2. One of those was stuff around line limits. It sets it to 90 as a compromise. Generally prefer 80 but don't complain if you have to go a little over. I was debating about going to 85 to stress the "prefer 80" but thought maybe that was too restrictive at the moment.

It also makes some concessions for lines which are long due to comments.

Happy to get your thoughts on that PR.

[csexton]

I prefer the 120 (which is why I added it to donkeykong). This is personal preference from back in days of yore, but my take:

1. It effects readability where we are forced to wrap lines just to make the cop happy
2. Drives up line count because we are wrapping things more often, which will trigger the too-many-lines cop
3. Discourages descriptive names

But, if we disagree then we fall back to the rubo-default.

[cupakromer]

IMO 120 is too long. Just to verify, I tested on my laptop and external monitor with a split code window. 120 wraps on both with just 2 window panes (b/c I also have line numbers, git gutter, etc.).

I thought Rubocop was smart enough to understand that a method with a multi-line call was "one-statement". I double checked and you're correct it's not 😞 so even just basic method param wrapping increases the method line count.

I applied the changes per #2 to test DK and CC to see how much the comment exceptions make a difference. This is what I found:

App	80 char	85 char	90 char	100 char	120 char
cc	299	250	208	132	69
dk	168	117	77	48	6

While I'd still personally prefer the 80 - 90 range, I'd be ok with setting it to 100. I can split that without a 2 window split forcing wrapping.

[jnebeker]

💯That sounds like a good compromise, we could maybe vote on 90 vs. 100 during today's DLL if we wanted.