# Test default GOPROXY and GOSUMDB
env GOPROXY=
env GOSUMDB=
go env GOPROXY
stdout '^https://proxy.golang.org,direct$'
go env GOSUMDB
stdout '^sum.golang.org$'
env GOPROXY=https://proxy.golang.org
go env GOSUMDB
stdout '^sum.golang.org$'

# Download direct from github.
[!net] skip
[!exec:git] skip
env GOSUMDB=sum.golang.org
env GOPROXY=direct
go get -d rsc.io/quote@v1.5.2
cp go.sum saved.sum

# Download from proxy.golang.org with go.sum entry already.
# Use 'go list' instead of 'go get' since the latter may download extra go.mod
# files not listed in go.sum.
go clean -modcache
env GOSUMDB=
env GOPROXY=
go list -x -deps rsc.io/quote
! stderr github
stderr proxy.golang.org/rsc.io/quote
! stderr sum.golang.org/tile
! stderr sum.golang.org/lookup/rsc.io/quote
cmp go.sum saved.sum

# Download again.
# Should use the checksum database to validate new go.sum lines,
# but not need to fetch any new data from the proxy.
rm go.sum
go list -mod=mod -x rsc.io/quote
! stderr github
! stderr proxy.golang.org/rsc.io/quote
stderr sum.golang.org/tile
stderr sum.golang.org/lookup/rsc.io/quote
cmp go.sum saved.sum

# test fallback to direct
env TESTGOPROXY404=1
go clean -modcache
rm go.sum
go list -mod=mod -x rsc.io/quote
stderr 'proxy.golang.org.*404 testing'
stderr github.com/rsc
cmp go.sum saved.sum

-- go.mod --
module m