Allow assignment generics on custom classes object name lintr

[jonkeane]

For assignment methods like names<-.class_name I'm seeing linting errors:

> lintr::lint(text = "`names<-.my_custom_class` <- function() 2", linters = lintr::object_name_linter())
<text>:1:1: style: Variable and function name style should be snake_case or symbols.
`names<-.my_custom_class` <- function() 2

This PR resolves this (by looking for <-. and replacing it with ., in strip_names() since the <- are stripped from the generics before they are used in the matching regex in the object name lintr.

Alternatively, I could try keeping <- in both the generic list and the function names that are being linted if we think that's a better approach.

[AshesITR]

Thanks for reporting this bug.
The actual problem here seems to be that the generic detection messes up.

`names<-`

is in .S3PrimitiveGenerics and thus should be considered to be a generic in and of itself. I'd prefer to fix the detection rather than automatically assume all <--functions are generic if and only if their non-setter versions are.

cc @MichaelChirico: lintr:::strip_names(.S3PrimitiveGenerics) removes "names<-" from the list of known generics. Do you remember why we needed strip_names() there and have an idea for a fix?

[jonkeane]

I'm happy to try removing strip_names() from the generics detection and seeing if the tests pass / using the compare_branches.R script to check if there are any regressions.

[AshesITR]

Hi @jonkeane, sorry for the late reply.
I've just locally tested removing strip_names() from the generics call and didn't notice any adverse side-effects.
So this really seems like the best way to fix the issue.

[jonkeane]

Is there anything you need from me to get this finished?

[AshesITR]

Just a few tiny things still need to be done:

1. revert the change to strip_names()
2. remove the strip_names() call from

   lintr/R/object_name_linters.R

   Line 65 in be7a7f2

   generics <- strip_names(c(

3. Add a bullet the NEWS, crediting yourself and citing this PR number (since there is no associated issue IINM)

[jonkeane]

Thanks for the follow up — I've done all three of those. I put the news at the end of the current list, but happy to move it elsewhere if that's perferable.

[AshesITR]

Thank you very much, almost ready to merge.

[AshesITR]

Maybe *object_name_linter() now correctly detects assignment generics (#843, @jonkeane)?

[jonkeane]

Done, and thank you, again!