# go.dev/issue/63507: in a module whose go.mod has no go directive, 'go get'
# synthesizes the version of the go command itself internally. The change must
# be reported against the version the module implicitly had, go 1.16, not
# against whichever go command happened to run.

env TESTGO_VERSION=go1.99

# No go directive: 'go get go@1.20' writes one. The module was implicitly at
# go 1.16, so this is an upgrade from 1.16, not a downgrade from go1.99.
# Moving past 1.17 expands the requirements, so the existing note applies.
go get go@1.20
stderr '^go: upgraded implicit go 1.16 => 1.20$'
stderr 'note: expanded dependencies to upgrade to go 1.17 or higher'
! stderr 'downgraded'
grep '^go 1.20$' go.mod

# The same holds when the new version is the version of the go command: the
# module still moves from the implicit go 1.16, so the change is reported.
cp go.mod.none go.mod
go get go@1.99
stderr '^go: upgraded implicit go 1.16 => 1.99$'
grep '^go 1.99$' go.mod
! grep '^toolchain' go.mod

# Below the implicit version is a real downgrade.
cp go.mod.none go.mod
go get go@1.15
stderr '^go: downgraded implicit go 1.16 => 1.15$'
grep '^go 1.15$' go.mod

# Writing the implicit version explicitly changes nothing, so it stays silent.
cp go.mod.none go.mod
go get go@1.16
! stderr 'implicit'
! stderr 'go: (added|upgraded|downgraded) go'
grep '^go 1.16$' go.mod

# A version go.mod really declared is reported without 'implicit', including
# when it declares the same 1.16 that the implicit version would have been.
cp go.mod.116 go.mod
go get go@1.20
stderr '^go: upgraded go 1.16 => 1.20$'
! stderr 'implicit'

cp go.mod.high go.mod
go get go@1.20
stderr '^go: downgraded go 1.25 => 1.20$'

cp go.mod.low go.mod
go get go@1.20
stderr '^go: upgraded go 1.18 => 1.20$'

# This is not specific to 'go get go@version'. Getting a package writes the
# directive as a side effect, and that is now reported too.
cp go.mod.none go.mod
go get rsc.io/quote@v1.5.2
stderr '^go: upgraded implicit go 1.16 => 1.99$'

-- go.mod --
module example.com/m

-- go.mod.none --
module example.com/m

-- go.mod.116 --
module example.com/m
go 1.16

-- go.mod.high --
module example.com/m
go 1.25

-- go.mod.low --
module example.com/m
go 1.18