Fails to detect new http routing patterns introduced in go1.22

[mattkasun]

mingo output:
go.mod declares version 1.23 but computed minimum is 1.1

go1.23 is required for proper functionality .... due to "GET\t/{$}" in http.Handler func

package main

import (
	"fmt"
	"net/http"
)

func main() {
	http.HandleFunc("GET\t/{$}", homeHandler)
	http.ListenAndServe(":8000", nil)
}

func homeHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintln(w, "hello world")
}

[bobg]

Thanks for this suggestion, but I think this is outside the scope of Mingo, at least for now. Mingo is strictly concerned with:

• language features;
• when identifiers were added to the standard library; and
• the declared Go version of dependencies.

What you're describing is a change to an existing stdlib function, which isn't any of those three.

Handling this specific change doesn't seem too hard on the face of it. But when you consider that the first argument to HandleFunc is not necessarily a constant, you quickly see that this is tractable only in some cases and intractable in general.

How many other changes in stdlib behavior like this one would Mingo also have to track? I suppose I could pore over the Go release notes to find out but really don't want to.

I can see adding a go vet-style mode to Mingo in the future that is happy to check things like this in a best-effort manner.

BTW, sorry for the long delay, I only just saw this now. Somehow GitHub failed to notify me originally about the appearance of this and your other issue.

[mattkasun]

understood. If and when you implement the go vet -style mode, an analyzer for this already exists.

htttpmux

report using Go 1.22 enhanced ServeMux patterns in older Go versions.

The httpmux analysis is active for Go modules configured to run with Go 1.21 or
earlier versions. It reports calls to net/http.ServeMux.Handle and HandleFunc
methods whose patterns use features added in Go 1.22, like HTTP methods (such as
"GET") and wildcards. (See https://pkg.go.dev/net/http#ServeMux for details.)
Such patterns can be registered in older versions of Go, but will not behave as expected.