feat: rewrite strings.SplitN(..., 2) to strings.Cut

[dnwe]

Use strings.Cut instead of strings.SplitN for cleaner string splitting

[ccoVeille]

My point was also to add SplitN -1 and Split for [1]

As you can see there are some out there.

[dnwe]

So I wrote this rule to catch "someone wrote valid and reasonable code with a clear intent (split into exactly two values), but it could be done in a cleaner more readable way that achieves the exact same result, here is an autofix to tidy that up for you" approach – a bit like the new gopls modernize package.

For $x := strings.Split($y, $delim)[1] and $x := strings.SplitN($y, $delim, -1)[1] the autofix is only valid if there are exactly two elements because the [1] equivalent in strings.Cut is "after", i.e., all elements after the delimiter, not just the second element alone

So whilst these two lines are equivalent:

port := strings.Split("host:port", ":")[1]
_, port, _ := strings.Cut("host:port", ":")

These two are not

want := strings.Split("a,b,c", ",")[1]
_, got, _ := strings.Cut("a,b,c", ",")

string differs (-got, +want):
  string(
- 	"b,c",
+ 	"b",
  )

(playground link)

[ccoVeille]

You are right.