How to handle a 200 response but response struct is not expected ?

[y4code]

The server response would be like

{
    "result": 0,
    "productCode": "111112"
}

and

{
    "result": 0,
    "messages": [
        {
            "message": "The productCode test_product_1 has been existed, try another one.",
            "ruleType": 1
        }
    ]
}

Here is my solution below trying to make this case elegant, not taking benefit of auto-unmarshal of resty caused i didn't find any document about this.

So, does resty give some solution or feature to handle a 200 response but the response body may be different in some cases?

func (s *proxyService) CreateProduct(dto *CreateProductPayloadDTO, token string) (*CreateProductResDTO, error) {
	var (
		payload                  []byte
		err                      error
		createProductRes         CreateProductResDTO
		createProductResErrorDTO CreateProductResErrorDTO
		res                      *resty.Response
	)
	if payload, err = json.Marshal(dto); err != nil {
		return nil, err
	}
	if res, err = http_util.R(s.Resty, s.Context, token, nil).
		SetBody(payload).
		SetResult(&createProductRes).
		Post(s.ProductHost + CreateProductEndpoint); err != nil || res.StatusCode() != 200 {
		return nil, errors.New("create product in platform failed" + res.String())
	}
	if createProductRes.ProductId == 0 && createProductRes.Result == 0 {
		if err = json.Unmarshal(res.Body(), &createProductResErrorDTO); err != nil {
			return nil, errors.New("create product in platform failed")
		}
		if createProductResErrorDTO.Result == 0 && len(createProductResErrorDTO.Messages) != 0 {
			return nil, errors.New("product code existed, try another one. " + createProductResErrorDTO.Messages[0].Message)
		}
	}
	return &createProductRes, nil
}

[y4code]

Of course a generic response dto is suitable for this case, but what about a quite different response ?

type GenericResDTO struct {
	Result   int `json:"result"`
	ProductId int64 `json:"productId"`
	Messages []struct {
		Message  string `json:"message"`
		RuleType int    `json:"ruleType"`
	} `json:"messages"`
}

[jeevatkm]

@y4code Have a look at the section Features on the readme. That mentions the details of auto unmarshal for success and error scenarios.
Then, if you follow the godoc from the readme.

• https://pkg.go.dev/github.com/go-resty/resty/v2#Request.SetResult
• https://pkg.go.dev/github.com/go-resty/resty/v2#Request.SetError

It covers details about HTTP status codes on method doc.

So, you can use your GenericResDTO on any scenario, and Resty does not limit you.