Implement a cop which tracks _-prefixed variables/params that are actually used

[bbatsov]

This came up in #931:

node.children.each do |_node|
  do_something(_node)
end

[bbatsov]

@yujinakayama Something else we might consider - an offense for unused block and method params:

def something(x)
  # x is not used
end

hash.each { |k, v| puts k } 

I guess such a check might be useful.

[yujinakayama]

@bbatsov My concern about unused arguments is that sometimes people have no control on them when overriding methods of superclass or conforming to some protocols. In that case, should we force users name the arguments with _ prefix?

[bbatsov]

On Wednesday, April 9, 2014, Yuji Nakayama [email protected] wrote:

@bbatsov https://github.com/bbatsov My concern about unused arguments
is that sometimes people have no control on them when overriding methods of
superclass. In that case, should we force users name the arguments with _prefix?

Seems reasonable to me. Those could be two cops (one for methods and one
for block params) so people can opt out if they don't like this.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/934#issuecomment-39905591
.

Best Regards,
Bozhidar Batsov

http://www.batsov.com

[yujinakayama]

Those could be two cops (one for methods and one for block params) so people can opt out if they don't like this.

👍