From 8aebea7ba23ae19899ad01b0c36bae867335f6b1 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Wed, 11 Sep 2024 21:31:05 +0200
Subject: [PATCH] fuse: test that the same fs.Node is used for the same file

---
 internal/fuse/fuse_test.go | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/internal/fuse/fuse_test.go b/internal/fuse/fuse_test.go
index 5818c1edd..6cd7a450a 100644
--- a/internal/fuse/fuse_test.go
+++ b/internal/fuse/fuse_test.go
@@ -217,6 +217,34 @@ func testTopUIDGID(t *testing.T, cfg Config, repo restic.Repository, uid, gid ui
 	rtest.Equals(t, uint32(0), attr.Gid)
 }
 
+// The Lookup method must return the same Node object unless it was forgotten in the meantime
+func testStableLookup(t *testing.T, node fs.Node, path string) fs.Node {
+	t.Helper()
+	result, err := node.(fs.NodeStringLookuper).Lookup(context.TODO(), path)
+	rtest.OK(t, err)
+	result2, err := node.(fs.NodeStringLookuper).Lookup(context.TODO(), path)
+	rtest.OK(t, err)
+	rtest.Assert(t, result == result2, "%v are not the same object", path)
+
+	result2.(fs.NodeForgetter).Forget()
+	result2, err = node.(fs.NodeStringLookuper).Lookup(context.TODO(), path)
+	rtest.OK(t, err)
+	rtest.Assert(t, result != result2, "object for %v should change after forget", path)
+	return result
+}
+
+func TestStableNodeObjects(t *testing.T) {
+	repo := repository.TestRepository(t)
+	restic.TestCreateSnapshot(t, repo, time.Unix(1460289341, 207401672), 2)
+	root := NewRoot(repo, Config{})
+
+	idsdir := testStableLookup(t, root, "ids")
+	snapID := loadFirstSnapshot(t, repo).ID().Str()
+	snapshotdir := testStableLookup(t, idsdir, snapID)
+	dir := testStableLookup(t, snapshotdir, "dir-0")
+	testStableLookup(t, dir, "file-2")
+}
+
 // Test reporting of fuse.Attr.Blocks in multiples of 512.
 func TestBlocks(t *testing.T) {
 	root := &Root{}