[#335] treesvc: Add GetSubTree ordering unit test

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/services/tree/getsubtree_test.go

@@ -3,6 +3,8 @@ package tree
 import (
 	"context"
 	"errors"
+	"path"
+	"sort"
 	"testing"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/pilorama"
@@ -119,6 +121,65 @@ func TestGetSubTree(t *testing.T) {
 	})
 }
 
+func TestGetSubTreeOrderAsc(t *testing.T) {
+	d := pilorama.CIDDescriptor{CID: cidtest.ID(), Size: 1}
+	treeID := "sometree"
+	p := pilorama.NewMemoryForest()
+
+	tree := []struct {
+		path []string
+		id   uint64
+	}{
+		{path: []string{"dir1"}},
+		{path: []string{"dir2"}},
+		{path: []string{"dir1", "sub1"}},
+		{path: []string{"dir2", "sub1"}},
+		{path: []string{"dir2", "sub2"}},
+		{path: []string{"dir2", "sub1", "subsub1"}},
+	}
+
+	for i := range tree {
+		path := tree[i].path
+		meta := []pilorama.KeyValue{
+			{Key: pilorama.AttributeFilename, Value: []byte(path[len(path)-1])}}
+
+		lm, err := p.TreeAddByPath(context.Background(), d, treeID, pilorama.AttributeFilename, path[:len(path)-1], meta)
+		require.NoError(t, err)
+		require.Equal(t, 1, len(lm))
+		tree[i].id = lm[0].Child
+	}
+
+	acc := subTreeAcc{errIndex: -1}
+	err := getSubTree(context.Background(), &acc, d.CID, &GetSubTreeRequest_Body{
+		TreeId: treeID,
+		OrderBy: &GetSubTreeRequest_Body_Order{
+			Direction: GetSubTreeRequest_Body_Order_Asc,
+		},
+	}, p)
+	require.NoError(t, err)
+	// GetSubTree must return child only after is has returned the parent.
+	require.Equal(t, uint64(0), acc.seen[0].Body.NodeId)
+
+	paths := make([]string, 0, len(acc.seen))
+	for i := range acc.seen {
+		if i == 0 {
+			continue
+		}
+		found := false
+		for j := range tree {
+			if acc.seen[i].Body.NodeId == tree[j].id {
+				found = true
+				paths = append(paths, path.Join(tree[j].path...))
+			}
+		}
+		require.True(t, found, "unknown node")
+	}
+
+	require.True(t, sort.SliceIsSorted(paths, func(i, j int) bool {
+		return paths[i] < paths[j]
+	}))
+}
+
 var (
 	errSubTreeSend           = errors.New("send finished with error")
 	errSubTreeSendAfterError = errors.New("send was invoked after an error occurred")