chore(tvix): move store golang bindings to tvix/store-go

Similar to the castore-go CL before, this also updates the store-go
bindings to the new layout.

Change-Id: Id73d7ad43f7d70171ab021728e303300c5db71f0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9788
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>

tvix/store-go/pick_next_node_test.go

@@ -0,0 +1,51 @@
+package storev1
+
+import (
+	"testing"
+
+	castorev1pb "code.tvl.fyi/tvix/castore/protos"
+	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/testing/protocmp"
+)
+
+func requireProtoEq(t *testing.T, expected interface{}, actual interface{}) {
+	if diff := cmp.Diff(expected, actual, protocmp.Transform()); diff != "" {
+		t.Errorf("unexpected difference:\n%v", diff)
+	}
+}
+
+func TestPopNextNode(t *testing.T) {
+	t.Run("empty directory", func(t *testing.T) {
+		d := &castorev1pb.Directory{
+			Directories: []*castorev1pb.DirectoryNode{},
+			Files:       []*castorev1pb.FileNode{},
+			Symlinks:    []*castorev1pb.SymlinkNode{},
+		}
+
+		n := drainNextNode(d)
+		require.Equal(t, nil, n)
+	})
+	t.Run("only directories", func(t *testing.T) {
+		ds := &castorev1pb.Directory{
+			Directories: []*castorev1pb.DirectoryNode{{
+				Name:   []byte("a"),
+				Digest: []byte{},
+				Size:   0,
+			}, {
+				Name:   []byte("b"),
+				Digest: []byte{},
+				Size:   0,
+			}},
+			Files:    []*castorev1pb.FileNode{},
+			Symlinks: []*castorev1pb.SymlinkNode{},
+		}
+
+		n := drainNextNode(ds)
+		requireProtoEq(t, &castorev1pb.DirectoryNode{
+			Name:   []byte("a"),
+			Digest: []byte{},
+			Size:   0,
+		}, n)
+	})
+}