Merge pull request #25 from go-zoox/fix/debug-marshal-config-error

fix: debug marshal config error because func cannot be marshal, shoul…

config.go

@@ -47,7 +47,7 @@ type Config struct {
 	//
 	Context context.Context
 	//
-	OnProgress func(percent int64, current, total int64)
+	OnProgress OnProgress
 	//
 	BasicAuth BasicAuth
 	//
@@ -61,6 +61,19 @@ type BasicAuth struct {
 	Password string
 }
 
+// OnProgress is the progress callback
+type OnProgress func(percent int64, current, total int64)
+
+// MarshalJSON returns the json string
+func (op *OnProgress) MarshalJSON() ([]byte, error) {
+	return []byte("null"), nil
+}
+
+// UnmarshalJSON unmarshals the json string
+func (op *OnProgress) UnmarshalJSON(data []byte) error {
+	return nil
+}
+
 // Merge merges the config with the given config
 func (c *Config) Merge(config *Config) {
 	if config == nil {