What version of Go are you using (go version)?

$ go version
go version devel go1.18-14e812bfc Fri Sep 17 00:31:49 2021 +0000 darwin/amd64
$ go list -m golang.org/x/tools golang.org/x/tools/gopls
golang.org/x/tools v0.1.6-0.20210902182115-3b801c8b8389
golang.org/x/tools/gopls v0.0.0-20210902182115-3b801c8b8389

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

$ go env
N/A

What did you do?

With the file structure below I opened up foo_test.go, move cursor to bar.Bar and tried to go to definition / hover / find references.

-- bar/bar.go --
package bar

import "foo"

const Bar = "bar"

const X = foo.Foo(false)
-- foo.go --
package foo

type Foo bool
-- foo_test.go --
package foo_test

import (
	"foo/bar"
	"testing"
)

func TestFoo(t *testing.T) {
	_ = bar.Bar // <= Hover / Go to def / Find refs / etc. from "Bar" here
}
-- go.mod --
module foo

go 1.18
-- other_test.go --
package foo

What did you expect to see?

Results from any of the requests.

What did you see instead?

No results.

It seems like the existence of other_test.go is the key here (i.e. both a _test.go file and package foo_test), if it isn't present everything works as expected.