env GO111MODULE=off

# go env should default to the right places
env AppData=$HOME/windowsappdata
env home=$HOME/plan9home
go env GOENV
[aix] stdout $HOME/.config/go/env
[darwin] stdout $HOME'/Library/Application Support/go/env'
[freebsd] stdout $HOME/.config/go/env
[linux] stdout $HOME/.config/go/env
[netbsd] stdout $HOME/.config/go/env
[openbsd] stdout $HOME/.config/go/env
[plan9] stdout $HOME/plan9home/lib/go/env
[windows] stdout $HOME\\windowsappdata\\go\\env

# Now override it to something writable.
env GOENV=$WORK/envdir/go/env
go env GOENV
stdout envdir[\\/]go[\\/]env

# go env shows all variables
go env
stdout GOARCH=
stdout GOOS=
stdout GOROOT=

# go env -w changes default setting
env root=
[windows] env root=c:
env GOPATH=
go env -w GOPATH=$root/non-exist/gopath
! stderr .+
grep GOPATH=$root/non-exist/gopath $WORK/envdir/go/env
go env GOPATH
stdout /non-exist/gopath

# go env -w does not override OS environment, and warns about that
env GOPATH=$root/other
go env -w GOPATH=$root/non-exist/gopath2
stderr 'warning: go env -w GOPATH=... does not override conflicting OS environment variable'
go env GOPATH
stdout $root/other

# but go env -w does do the update, and unsetting the env var exposes the change
env GOPATH=
go env GOPATH
stdout $root/non-exist/gopath2

# unsetting with go env -u does not warn about OS environment overrides,
# nor does it warn about variables that haven't been set by go env -w.
env GOPATH=$root/other
go env -u GOPATH
! stderr .+
go env -u GOPATH
! stderr .+

# go env -w rejects unknown or bad variables
! go env -w GODEBUG=gctrace=1
stderr 'unknown go command variable GODEBUG'
! go env -w GOEXE=.bat
stderr 'GOEXE cannot be modified'
! go env -w GOENV=/env
stderr 'GOENV can only be set using the OS environment'

# go env -w can set multiple variables
env CC=
go env CC
! stdout ^xyc$
go env -w GOOS=$GOOS CC=xyc
grep CC=xyc $GOENV
# file is maintained in sorted order
grep 'CC=xyc\nGOOS=' $GOENV
go env CC
stdout ^xyc$

# go env -u unsets effect of go env -w.
go env -u CC
go env CC
! stdout ^xyc$

# go env -w rejects double-set variables
! go env -w GOOS=$GOOS GOOS=$GOOS
stderr 'multiple values for key: GOOS'

# go env -w rejects missing variables
! go env -w GOOS
stderr 'arguments must be KEY=VALUE: invalid argument: GOOS'

# go env -w rejects invalid GO111MODULE values, as otherwise cmd/go would break
! go env -w GO111MODULE=badvalue
stderr 'invalid GO111MODULE value "badvalue"'

# go env -w rejects invalid GOPATH values
! go env -w GOPATH=~/go
stderr 'GOPATH entry cannot start with shell metacharacter'

! go env -w GOPATH=./go
stderr 'GOPATH entry is relative; must be absolute path'

# go env -w/-u checks validity of GOOS/ARCH combinations
env GOOS=
env GOARCH=
# check -w doesn't allow invalid GOOS
! go env -w GOOS=linuxx
stderr 'unsupported GOOS/GOARCH pair linuxx'
# check -w doesn't allow invalid GOARCH
! go env -w GOARCH=amd644
stderr 'unsupported GOOS/GOARCH.*/amd644$'
# check -w doesn't allow invalid GOOS with valid GOARCH
! go env -w GOOS=linuxx GOARCH=amd64
stderr 'unsupported GOOS/GOARCH pair linuxx'
# check a valid GOOS and GOARCH values but an incompatible combinations
! go env -w GOOS=android GOARCH=s390x
stderr 'unsupported GOOS/GOARCH pair android/s390x'
# check that -u considers explicit envs
go env -w GOOS=linux GOARCH=mips
env GOOS=windows
! go env -u GOOS
stderr 'unsupported GOOS/GOARCH.*windows/mips$'