Why in some cases error model is set even if request is a success?

[thetarby]

In middleware.go, the code where error is set to nil is never reached if status is 201 no content because of the if block at the beginning of the method.

func parseResponseBody(c *Client, res *Response) (err error) {
	if res.StatusCode() == http.StatusNoContent {
		return
	}
	// Handles only JSON or XML content type
	ct := firstNonEmpty(res.Request.forceContentType, res.Header().Get(hdrContentTypeKey), res.Request.fallbackContentType)
	if IsJSONType(ct) || IsXMLType(ct) {
		// HTTP status code > 199 and < 300, considered as Result
		if res.IsSuccess() {
			res.Request.Error = nil
			if res.Request.Result != nil {
				err = Unmarshalc(c, ct, res.body, res.Request.Result)
				return
			}
		}

		// HTTP status code > 399, considered as Error
		if res.IsError() {
			// global error interface
			if res.Request.Error == nil && c.Error != nil {
				res.Request.Error = reflect.New(c.Error).Interface()
			}

			if res.Request.Error != nil {
				err = Unmarshalc(c, ct, res.body, res.Request.Error)
			}
		}
	}

	return
}

This makes it impossible to check errors like

errM := resp.Error()
if errM == nil {
          // ...
}

This does not seem to be the desired behavior to me, am I missing something or is this an issue?

[kecci]

Hi @thetarby,

Before the discussion, I assume you are refer the code of middleware was get from here: https://github.com/go-resty/resty/blob/master/middleware.go#L322

As we can see, the func called parseResponseBody which is the something to do with parsing response body to another thing.

And status code 201 it's not an error, just a http status that show response the empty content.

If you want to makesure this is empty content, you can have 2 ways to validate it:

Option 1, using res.StatusCode() == http.StatusNoContent:

	if res.StatusCode() == http.StatusNoContent {
		return errors.New("the response is no content")
	}

Option 2, using res.Body == nil:

	if res.Body == nil {
		return errors.New("the response is no content")
	}

Hopefully this could be help your discussion.