cmd/gofmt: inconsistent indentation for comments inside switch-case

[subsr97]

What version of Go are you using (go version)?

$ go version
go version go1.11.4 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/local/ZOHOCORP/mani-pt2396/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/local/ZOHOCORP/mani-pt2396/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build688297931=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Commented out the last case of switch with line or block comment(s).

https://play.golang.org/p/fkseigRrxYV

What did you expect to see?

The last case(s) to be in their place and not go inside the scope of the previous case.

	switch val {
	case foo1:
		foo()
	case foo2:
		foo()
	// case bar:
		// bar()
	}

	switch val {
	case foo1:
		foo()
	case foo2:
		foo()
	/* case bar:
		// bar()*/
	}

What did you see instead?

The last case(s) is aligned as if it is inside the scope of the previous case.

	switch val {
	case foo1:
		foo()
	case foo2:
		foo()
		// case bar:
		// bar()
	}

	switch val {
	case foo1:
		foo()
	case foo2:
		foo()
		/* case bar:
		// bar()*/
	}

[agnivade]

Maybe good to fix, but the heuristics are complicated. How do we know whether we are not actually commenting out code inside the last case ?

Although I agree we should be consistent in the indentation whether we are in the middle of a switch-case or at the end. Currently, it seems there is an inconsistency.

package main

func main() {
	val := 1
	switch val {
	case 1:
		_ = 1
	// case 5: // gets aligned to the case
	// 	_ = 5
	case 2:
		_ = 2
		// case 3: // gets aligned to the code block inside the case
		// 	_ = 3
	}
}

@griesemer

[josharian]

I’m 95% confident this is a dup. On my phone and can’t find the original (apologies?), but there has been significant discussion of indent, gofmt, and switch cases on some other issue.

[subsr97]

@josharian Are you referring to #28057?

[josharian]

Yes. And in a related vein there's also #20681 and #9910. And perhaps others.

[griesemer]

Leaving open for future consideration. Unfortunately, gofmt work is not currently a priority for us as long as code is not broken by it, so theses issues will linger a bit. The good news is that when we eventually get to addressing these, we have a lot of corner cases to test against. And once fixed, it's trivial to "fix" huge corpuses of code in one fell swoop.