diff --git a/mfs/mfs_test.go b/mfs/mfs_test.go index 42a87fde4..c91d77168 100644 --- a/mfs/mfs_test.go +++ b/mfs/mfs_test.go @@ -1136,3 +1136,43 @@ func TestTruncateAtSize(t *testing.T) { } fd.Truncate(4) } + +func TestTruncateAndWrite(t *testing.T) { + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + ds, rt := setupRoot(ctx, t) + + dir := rt.GetDirectory() + + nd := dag.NodeWithData(ft.FilePBData(nil, 0)) + fi, err := NewFile("test", nd, dir, ds) + if err != nil { + t.Fatal(err) + } + + fd, err := fi.Open(OpenReadWrite, true) + defer fd.Close() + if err != nil { + t.Fatal(err) + } + for i := 0; i < 200; i++ { + err = fd.Truncate(0) + if err != nil { + t.Fatal(err) + } + l, err := fd.Write([]byte("test")) + if err != nil { + t.Fatal(err) + } + if l != len("test") { + t.Fatal("incorrect write length") + } + data, err := ioutil.ReadAll(fd) + if err != nil { + t.Fatal(err) + } + if string(data) != "test" { + t.Errorf("read error at read %d, read: %v", i, data) + } + } +}