# Test support for go mod edit -toolchain to set toolchain to use

env GOTOOLCHAIN=local
env GO111MODULE=on

! grep toolchain go.mod
go mod edit -toolchain=go1.9
grep 'toolchain go1.9' go.mod

go mod edit -toolchain=default
grep 'toolchain default' go.mod

go mod edit -toolchain=none
! grep toolchain go.mod

-- go.mod --
module m

# with --mod=readonly moduleInfo was not setting the GoVersion for the module
# because the checksumOk function was failing because modfetch.GoSumFile
# was not set when running outside of a module.

env GOTOOLCHAIN=local

env TESTGO_VERSION=go1.21
env TESTGO_VERSION_SWITCH=switch
env GOTOOLCHAIN=auto
cp go.mod.new go.mod
cp go.work.new go.work
go get rsc.io/needgo121 rsc.io/needgo122 rsc.io/needgo123 rsc.io/needall
stderr '^go: rsc.io/needall@v0.0.1 requires go >= 1.23; switching to go1.23.9$'
stderr '^go: added rsc.io/needall v0.0.1'
grep 'go 1.23$' go.mod
grep 'go 1.23$' go.work
grep 'toolchain go1.23.9' go.mod

env GOTOOLCHAIN=auto
env TESTGO_VERSION=go1.21.1

# Basic switch should work.
env TESTGO_VERSION_SWITCH=switch
go version
stdout go1.21.99

# Toolchain target mismatch should be detected.
env TESTGO_VERSION_SWITCH=mismatch
! go version
stderr '^go: toolchain go1.21.1 invoked to provide go1.21.99$'

# Toolchain loop should be detected.
env TESTGO_VERSION_SWITCH=loop
! go version

	GOHOSTARCH
	GOHOSTOS
	GOINSECURE
	GOMIPS
	GOMIPS64
	GOMODCACHE
	GONOPROXY
	GONOSUMDB
	GOOS
	GOPATH
	GOPPC64
	GOPRIVATE
	GOPROXY
	GORISCV64
	GOROOT
	GOSUMDB
	GOTMPDIR
	GOTOOLCHAIN
	GOTOOLDIR
	GOVCS
	GOWASM
	GOWORK
	GO_EXTLINK_ENABLED
	PKG_CONFIG

# Go should refuse to build code that is too new according to go.mod.

# go.mod too new
env GOTOOLCHAIN=local
! go build .
stderr '^go: go.mod requires go >= 1.99999 \(running go 1\..+\)$'

# go.mod referenced from go.work too new
cp go.work.old go.work
! go build .
stderr '^go: module . listed in go.work file requires go >= 1.99999, but go.work lists go 1.10; to update it:\n\tgo work use$'

! go work sync

  if [ "${GOTOOLCHAIN:-auto}" != 'auto' ]; then
    # no-op, just respect GOTOOLCHAIN
    :
  elif [ -n "${FORCE_HOST_GO:-}" ]; then
    # ensure existing host version is used, like before GOTOOLCHAIN existed
    export GOTOOLCHAIN='local'
  else
    # otherwise, we want to ensure the go version matches GO_VERSION
    GOTOOLCHAIN="go${GO_VERSION}"
    export GOTOOLCHAIN

// A toolchainRepo is a synthesized repository reporting Go toolchain versions.
// It has path "go" or "toolchain". The "go" repo reports versions like "1.2".
// The "toolchain" repo reports versions like "go1.2".
//
// Note that the repo ONLY reports versions. It does not actually support
// downloading of the actual toolchains. Instead, that is done using
// the regular repo code with "golang.org/toolchain".

//
// To test that the module downloads are usable with the go command:
//
//	./make.bash -distpack
//	mkdir -p /tmp/goproxy/golang.org/toolchain/
//	ln -sf $(pwd)/../pkg/distpack /tmp/goproxy/golang.org/toolchain/@v
//	GOPROXY=file:///tmp/goproxy GOTOOLCHAIN=$(sed 1q ../VERSION) gotip version
//
// gotip can be replaced with an older released Go version once there is one.
// It just can't be the one make.bash built, because it knows it is already that

			if env[i].Value != "" {
				env[i].Changed = true
			}
		case "GOCACHE":
			env[i].Value, env[i].Changed = cache.DefaultDir()
		case "GOTOOLCHAIN":
			env[i].Value, env[i].Changed = cfg.EnvOrAndChanged("GOTOOLCHAIN", "")
		case "GODEBUG":
			env[i].Changed = env[i].Value != ""
		}
	}

	if work.GccgoBin != "" {