How to unmarshal a reflect.Value in Golang

I got this test

func (t *DeviceTests) CreatePublicDevice() {
	registerRegularDevice := tester.TableTest{
		Method:      "POST",
		Path:        "/iot/devices",
		Status:      http.StatusOK,
		Name:        "CreatePublicDevice",
		Description: "register Regular Device has to return 200",
		Body:        PublicDevice,
	}
	resp := registerRegularDevice.DoubleSpin(t.Test)
	log.Println(resp.(types.Device).ID)

}

I want to keep this in a separate package so I can reuse on diferent projects.

func (test TableTest) DoubleSpin(t *testing.T) interface{} {
	actualBody := test.innnerSpin(t)
	log.Print(string(actualBody))
	thetype := reflect.TypeOf(test.Body)
	log.Println(thetype)
	receivedev := reflect.Zero(thetype)
	err := json.Unmarshal(actualBody, receivedev.Interface())
	assert.NoError(t, err)
	log.Println(receivedev)
	return receivedev.Interface()
}

Logs say:

2016/11/06 16:54:01 {"id":"581f7c49b2c79a543c627474","hostname":"Shriekersolar","alias":"my PublicDevice","channels":8,"owner":"public","location":{}}
2016/11/06 16:54:01 types.Device
2016/11/06 16:54:01 {ObjectIdHex("")   0  map[]}
2016/11/06 16:54:01 ObjectIdHex("")

Where a device looks like:

type Device struct {
	ID       bson.ObjectId     `json:"id" bson:"_id,omitempty"`
	Hostname string            `json:"hostname"`
	Alias    string            `json:"alias"`
	Channels int               `json:"channels"`
	Owner    string            `json:"owner"`
	Location map[string]string `json:"location"`
}

Use reflect.New rather than reflect.Zero to get a pointer:

thetype := reflect.TypeOf(i)
receivedev := reflect.New(thetype)
err := json.Unmarshal(actualBody, receivedev.Interface())
if err != nil {
	panic(err)
}

Playground: https://play.golang.org/p/pGXRWpBFiF.