garble test fails to resolve test-scoped dependency packages listed as "pkg [pkg.test]"

[zamai]

Output of garble version:

mvdan.cc/garble v0.15.0

Build settings:
-buildmode exe
-compiler gc
DefaultGODEBUG cryptocustomrand=1,tlssecpmlkem=0,urlstrictcolons=0
CGO_ENABLED 1
GOARCH arm64
GOOS darwin
GOARM64 v8.0

Output of go env in your module/workspace:

-> % go env
AR='ar'
CC='cc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='c++'
GCCGO='gccgo'
GO111MODULE=''
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/alex/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/alex/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/xx/_y62swfx7wngnmzb40174vb80000gn/T/go-build4051403362=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/alex/Code/garble/go.mod'
GOMODCACHE='/Users/alex/go/pkg/mod'
GONOPROXY='github.com/castai/*'
GONOSUMDB='github.com/castai/*,gitlab.com/castai/*'
GOOS='darwin'
GOPATH='/Users/alex/go'
GOPRIVATE='github.com/castai/*'
GOPROXY='https://us-central1-go.pkg.dev/cicd-master-oxk5/go-modules,https://proxy.golang.org,direct'
GOROOT='/opt/homebrew/Cellar/go/1.26.1/libexec'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/alex/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN=''
GOTOOLDIR='/opt/homebrew/Cellar/go/1.26.1/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.26.1'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

I am garble test over the repo that had mock.
I reproduced this with a integration test: test_scoped_module.txtar

# A package used only via export_test.go can be listed under a test-scoped
# import path like "pkg/path [pkg.test]". Garble must resolve that form too.

env GOGARBLE=test/bar

exec go test ./internal/foo
stdout 'ok\s+test/bar/internal/foo'

exec go list -deps -test ./internal/foo
stdout 'test/bar/mocks/foo \[test/bar/internal/foo.test\]'

exec garble test ./internal/foo
stdout 'ok\s+test/bar/internal/foo'
-- go.mod --
module test/bar

go 1.23
-- internal/foo/foo.go --
package foo

func LocalFoo(v interface{ Foo() string }) string {
	return v.Foo()
}
-- internal/foo/export_test.go --
package foo

type ExportedFoo interface {
	Foo() string
}

-- internal/foo/foo_test.go --
package foo_test

import (
	"testing"

	"test/bar/internal/foo"
	mockfoo "test/bar/mocks/foo"
)

func TestFoo(t *testing.T) {
	if got := foo.LocalFoo(mockfoo.MockFoo{}); got != "Foo" {
		t.Fatalf("LocalFoo() = %q", got)
	}
}

-- mocks/foo/foo.go --
package foo

import under_test "test/bar/internal/foo"

var _ under_test.ExportedFoo = MockFoo{}

type MockFoo struct{}

func (MockFoo) Foo() string { return "Foo" }

(pity that I can't attach file here, but it's also in my draft RP: #1017

What did you see happen?

go test passes:

$ go test ./internal/foo
ok test/bar/internal/foo
go list -deps -test shows the important package shape:

$ go list -deps -test ./internal/foo
...
test/bar/internal/foo [test/bar/internal/foo.test]
test/bar/mocks/foo [test/bar/internal/foo.test]
test/bar/internal/foo_test [test/bar/internal/foo.test]
test/bar/internal/foo.test

But garble test fails:

$ GOGARBLE=test/bar garble test ./internal/foo
# test/bar/internal/foo.test
list test/bar/mocks/foo: not found
FAIL	test/bar/internal/foo [build failed]
FAIL

So the failure seems to be that garble only looks up test/bar/mocks/foo, while go list -deps -test only recorded it under the test-scoped form test/bar/mocks/foo [test/bar/internal/foo.test].

What did you expect to see?

garble test ./internal/foo should behave like go test ./internal/foo and pass.

go list -deps -test is allowed to report the mock package under a test-scoped import path like:

test/bar/mocks/foo [test/bar/internal/foo.test]

Garble should resolve that dependency correctly instead of only looking up the plain import path.

[mvdan]

I think this is user error; adjust your script to do go test ./... rather than go test ./internal/foo and you will see a clear error that I think is correct.

The fact that go test ./internal/foo works is, I think, a bug. You have a non-test package which imports a non-test package, and tries to access a test-package-exported name. That should not exist, unless I'm missing something.

In any case, I don't think you want to be using export_test.go like this. Its use is to export names to the test package in the same directory, not in other directories or packages. For that, you actually need to export the name in a non-test file.

[zamai]

@mvdan thanks for the reply.
i tried with the ./... pattern - the same issue.

here is the minimal example repo I've created to showcase the bug: https://github.com/zamai/garble-example/blob/main/Makefile#L17 - in that makefile the test internal command - works fine, but the test-garble-external fails. Which is the same scenario we are facing with our production code.

github.com/example/garble-repro/mocks/greeter - is not the test package because this is how https://github.com/vektra/mockery is generating our mocks.

[mvdan]

I'm not saying that garble test ./... would work, I am saying that go test ./... fails with your original example. The way the code and test packages are laid out is incorrect.

[zamai]

In the example I've linked, go test ./... - works, garble test fails.

https://github.com/zamai/garble-example/blob/main/Makefile#L21
https://github.com/zamai/garble-example/blob/main/Makefile#L6

laid out is incorrect.

Not sure that I understand why the code I have in the example is incorrect, this the real use case with mocks that we have in our codebase...

[mvdan]

Please note I'm talking about your original example. Are you intending that I discard it and look at your new example instead?

[zamai]

@mvdan yes, my intention was that it's simpler to see the failure mode, and easier to reason when it's a separate repo.
https://github.com/zamai/garble-example