Use Rubocop for some brew audits

[MikeMcQuaid]

We should investigate using Rubocop for some (maybe all) brew audits rather than just regex as Rubocop can actually parse Ruby.

[maxnordlund]

I might be able to take a stab at this, seems doable. But I would like some pointers though. May I please have some? (Also maybe you could ping the right persons @MikeMcQuaid)

[jawshooah]

Take a look at rubocop-cask as an example of custom cops and parsing logic.

[maxnordlund]

Nice, will do 👍 . But should I then point a PR to that repo or put inside here somewhere (and then what is a good place)?

[maxnordlund]

Or make a new repo, but that seems like overkill.

[MikeMcQuaid]

@maxnordlund That would be so great! I agree that probably having it inside this repo would be ideal, if that's possible (similarly maybe with rubocop-cask one day). @jawshooah any thoughts on why you made it a separate repo to avoid hitting any issues you may have hit?

Regardless, I wouldn't worry too much about location or even completeness for now; I'd pick a single rule from brew audit that looks like a good candidate for Rubocop and try and get the flow working end-to-end and then we can look at porting other rules across.

[maxnordlund]

Sounds like a plan, I'll make a new repo and steal/borrow the cask rubocop structure and do as you say and implement a single rule. We can always move the code around if needed I guess.

[MikeMcQuaid]

A suggestion for an easy single rule that requires understanding Ruby more than audit really can currently: revision in a bottle do block should be renamed to rebuild and Rubocop should autocorrect it to rebuild.

[maxnordlund]

I haven't been able to get this rolling because a lot of stuff have cropped up at work. I still will try to do this, but it may take quite some time.

[MikeMcQuaid]

@maxnordlund No worries or rush.

[GauthamGoli]

@MikeMcQuaid I could work on implementing this feature. I implemented a basic cop that you mentioned above.

revision in a bottle do block should be renamed to rebuild and Rubocop should autocorrect it to rebuild

I tested it on a formula and its working fine. The link to the code: https://github.com/GauthamGoli/rubocop-brew . Please let me know what you think
as I'm still trying to understand how to write custom cops, and also am a ruby novice.

Command to run the custom cop
$rubocop --require /absolute/path/to/custom_cop.rb --only CustomCops/CorrectBottleBlock --auto-correct /path/to/test/formula.rb

[MikeMcQuaid]

@GauthamGoli That looks like a great start, nice work! Next step and I'd consider this done would be to submit a PR to add bottle_block_cop.rb to Homebrew somewhere so it can be run without needing manual arguments. @jawshooah may have input on how to (or how best to) do this such that it'll also work for people running rubocop locally without configuration (that's my end goal/dream).

[GauthamGoli]

@MikeMcQuaid We can place bottle_block_cop.rb (and other custom cops) in a directory, I used Library/Homebrew/cops/ and then used the require directive in .rubocop.yml file to specify them. Without further configuration, the custom cop was getting executed locally and detecting violations when --strict argument is passed to brew audit. There is one final issue though, --strict just checks for cop violations, but for autocorrecting the code, may be a new option should be added to brew audit, let's say --fix may be ?

[MikeMcQuaid]

I used Library/Homebrew/cops/ and then used the require directive in .rubocop.yml file to specify them.

Nice! I think Library/Homebrew/rubocops/ would be best.

There is one final issue though, --strict just checks for cop violations, but for autocorrecting the code, may be a new option should be added to brew audit, let's say --fix may be ?

Yeh, that works. It's already there on brew style: https://github.com/Homebrew/brew/blob/master/Library/Homebrew/cmd/style.rb#L8-L9

[GauthamGoli]

@MikeMcQuaid Can porting audit rules to use Rubo Cop be a GSoC project?

[MikeMcQuaid]

@GauthamGoli Yep, that seems like a good one 👍

[MikeMcQuaid]

Going to consider this basically done at this point. Great work again, @GauthamGoli and hope that you'll keep doing some bits on this!