[Proposal] x/mod: api to get the module path that will be loaded by go mod in code ?

[dfang]

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

$ go version
go version go1.12.1 darwin/amd64

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

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/mj/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/mj/go"
GOPROXY="https://goproxy.io"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.12.1/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.1/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/mj/src/qor-demo/go.mod"
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/xb/dsd0_2b92x7bsl92xlzj6fbm0000gn/T/go-build351214963=/tmp/go-build -gno-record-gcc-switches -fno-common"

What do you want ?

in go.mod file

github.com/a/b

there are many dependencies, how do i get the path for this mod that will be loaded in a/b module ?

$GOPATH/pkg/mod/github.com/a/b@<hash>

simply read go.mod is not enough, because there may be lines for go mod edit --replace

or go mod vendor

want to get the results like this in code

go list -deps -f '{{with .Module}}{{.Path}}@{{.Version}}{{end}}' ./... | sort -u

internal package can do this, but it can't be called

[bcmills]

You can always execute go list -json as a subprocess. (That's why the -json flag exists!)

Depending on exactly which details you need, you may be able to use golang.org/x/tools/go/packages instead.

What's the underlying problem you're trying to solve? (What is it that you want to do with the path once you've found it?)

CC @ianthehat

[bcmills]

What's the underlying problem you're trying to solve?

I'm guessing that's #32384, in which case there really isn't an API that does what you're after.

[dfang]

@bcmills, internal packages for go list seems can do this, but it can't be called :(

yes, i'm trying to solve is #32384. i'm forking all github.com/qor sub projects, try to add mod support for viewpaths.

for example. in https://github.com/qor/admin/blob/master/admin.go#L102
if RegisterViewPath like this. template can be found when run in go mod way in Dockerfile.

it's not suitable for go list -json or golang.org/x/tools/go/packages here, i want to register viewpath in every sub project, not in module depends on them

currently my workaround is:

_, filename, _, _ := runtime.Caller(0)
dir := path.Join(path.Dir(filename), "views")
log.Debug().Str("viewpath", dir).Msg("registering viewpath")
admin.RegisterViewPath(dir)