[Cop request]: UnneededRequireFileExtension

[TSMMark]

Is your feature request related to a problem? Please describe.

.rb is not necessary when require or require_relative a Ruby file. When performing code review I am having to ask contributors to remove the superfluous file extension.

Describe the solution you'd like

When given:

require_relative "./whatever.rb"
require "../foo/bar.rb"

Autocorrect to:

require_relative "./whatever"
require "../foo/bar"

[TSMMark]

I would be happy to implement this cop myself given a pointer or two.

[koic]

It seems to be good overall to me.

It is a caution. *.rb, *.o, *.so, and other extensions are searched if the extension is omitted. (*.rb takes precedence) .
https://ruby-doc.org/core-2.6.4/Kernel.html#method-i-require

There is an edge case where foo.so file is loaded instead of a LoadError if foo.so file exists when require 'foo.rb' will be changed to require 'foo'.

FYI, the cop name should use Redundant instead of Unneeded. And I think it's probably the Style department, not the Lint department.
#7077

@rubocop-hq/rubocop-core Is there anything you are worrying about?

[jonas054]

It looks safe to me. Since *.rb takes precedence I can't see any risk that removing .rb would alter the behavior, except for the edge case @koic mentioned, but that seems harmless.

[jonas054]

@TSMMark Start by reading Contributing and let us know if you have any questions. For this cop I think you should implement on_send and check calls to require and require_relative. Call the cop Style/RedundantFileExtensionInRequire.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution and understanding!

[stale]

This issues been automatically closed due to lack of activity. Feel free to re-open it if you ever come back to it.

[TSMMark]

Sorry y'all I totally lost track of this ticket! @fatkodima you rock!