storage: fix noop writer to help dumpling to do some tests (#1248) (#…

…1258)

pkg/storage/noop.go

@@ -39,7 +39,7 @@ func (s *noopStorage) URI() string {
 
 // Create implements ExternalStorage interface.
 func (*noopStorage) Create(ctx context.Context, name string) (ExternalFileWriter, error) {
-	panic("noop storage not support multi-upload")
+	return &noopWriter{}, nil
 }
 
 func newNoopStorage() *noopStorage {
@@ -49,13 +49,23 @@ func newNoopStorage() *noopStorage {
 type noopReader struct{}
 
 func (noopReader) Read(p []byte) (n int, err error) {
-	return 0, nil
+	return len(p), nil
 }
 
 func (noopReader) Close() error {
 	return nil
 }
 
 func (noopReader) Seek(offset int64, whence int) (int64, error) {
-	return 0, nil
+	return offset, nil
+}
+
+type noopWriter struct{}
+
+func (noopWriter) Write(ctx context.Context, p []byte) (int, error) {
+	return len(p), nil
+}
+
+func (noopWriter) Close(ctx context.Context) error {
+	return nil
 }