filelu: run the chunked upload integration tests

Implement SetUploadChunkSizer and SetUploadCutoffer in the tests so
fstests can exercise the multipart upload path with small chunk sizes.

backend/filelu/filelu_internal_test.go

@@ -0,0 +1,29 @@
+package filelu
+
+import (
+	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fstest/fstests"
+)
+
+// SetUploadChunkSize changes the configured chunk size, returning the old value.
+//
+// It is only called by the integration tests while no transfer is in progress.
+func (f *Fs) SetUploadChunkSize(cs fs.SizeSuffix) (fs.SizeSuffix, error) {
+	var old fs.SizeSuffix
+	old, f.opt.ChunkSize = f.opt.ChunkSize, cs
+	return old, nil
+}
+
+// SetUploadCutoff changes the configured upload cutoff, returning the old value.
+//
+// It is only called by the integration tests while no transfer is in progress.
+func (f *Fs) SetUploadCutoff(cutoff fs.SizeSuffix) (fs.SizeSuffix, error) {
+	var old fs.SizeSuffix
+	old, f.opt.UploadCutoff = f.opt.UploadCutoff, cutoff
+	return old, nil
+}
+
+var (
+	_ fstests.SetUploadChunkSizer = (*Fs)(nil)
+	_ fstests.SetUploadCutoffer   = (*Fs)(nil)
+)

backend/filelu/filelu_test.go

@@ -12,5 +12,8 @@ func TestIntegration(t *testing.T) {
 		RemoteName:      "TestFileLu:",
 		NilObject:       nil,
 		SkipInvalidUTF8: true,
+		ChunkedUpload: fstests.ChunkedUploadConfig{
+			MinChunkSize: 1,
+		},
 	})
 }