Upgrade to go 1.22

[jesseduffield]

Is your feature request related to a problem? Please describe.
go 1.22 is out and notably it updates the way that loops are handled:

Previously, the variables declared by a “for” loop were created once and updated by each iteration. In Go 1.22, each iteration of the loop creates new variables, to avoid accidental sharing bugs. The transition support tooling described in the proposal continues to work in the same way it did in Go 1.21.

This is a very good improvement: it means we don't need to say x := x on the first line of any loop in which x will be closed over by a function. The reason I'm raising this issue is because just now I had a bug because I forgot to add x := x myself!

Describe the solution you'd like
Let's upgrade to go 1.22 and go find all the places we're doing x := x in loops and delete those lines.

[kyu08]

As you may already know, by using a linter called copyloopvar, you can detect unnecessary assignments. Once the update to Go 1.22 is complete, enabling this linter would reduce the effort of having to point out these issues during PR reviews.

To enable copyloopvar:

diff --git a/.golangci.yml b/.golangci.yml
index 85a95650..5b7c5e32 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -14,6 +14,7 @@ linters:
     - exhaustive
     - makezero
     - nakedret
+    - copyloopvar
     # - goconst # TODO: enable and fix issues
   fast: false

For example, if there was unnecessary assignment, output is like this:

$ golangci-lint run -c ./.golangci.yml  ./...
pkg/app/app.go:161:3: The copy of the 'for' variable "repoDir" can be deleted (Go 1.22+) (copyloopvar)
                repoDir := repoDir
                ^

[jesseduffield]

Ah nice! Would you be up to raising a PR for that @kyu08 ?

[kyu08]

Sure! I'd be happy to do that. 👍

[jesseduffield]

Awesome, thanks