Customer marshaller not invoked

[vocoded]

I discovered this as a breaking change in gin during the time when jsoniter was made the default JSON renderer. I have a struct that looks something like this:

type GeoLocation struct {
	Id             string     `json:"id,omitempty" db:"id"`
	Latitude       null.Float `json:"latitude" db:"latitude"`
	Longitude      null.Float `json:"longitude" db:"longitude"`
	CreateTime     null.Int   `json:"createTime" db:"-"`
	Created        util.NullableTime   `json:"-" db:"created"`
	Received       util.NullableTime   `json:"-" db:"received"`
}

And a custom marshaller defined on the pointer of this type:

func (p *GeoLocation) MarshalJSON() ([]byte, error) {
	var created string
	var received string
	if p.Created.Valid {
		created = p.Created.Time.Format("2006-01-02 15:04:05")
		p.CreateTime.SetValid(p.Created.Time.Unix())
	}

	if p.Received.Valid {
		received = p.Received.Time.Format("2006-01-02 15:04:05")
	}

	type GeoLocationJSON GeoLocation
	return json.Marshal(&struct {
		*GeoLocationJSON
		CreateTime string `json:"created"`
		ReceivedTime string `json:"received"`
	}{
		CreateTime:      created,
		ReceivedTime:    received,
		GeoLocationJSON: (*GeoLocationJSON)(p),
	})
}

When rendering a gin response with a slice of these objects, such as:

var locations []GeoLocation
locations = getLocations()
c.JSON(200, locations)

The custom marshaller is not invoked. Changing the marshaller signature to use a value receiver (ie, func (p GeoLocation) MarshalJSON() ([]byte, error)) does work.

The stdlib version of json handles this as expected.

[taowen]

should be fixed now