Optimize SetResponseBodyTransformer

client.go

@@ -66,7 +66,7 @@ type Client struct {
 	udBeforeRequest         []RequestMiddleware
 	afterResponse           []ResponseMiddleware
 	wrappedRoundTrip        RoundTripper
-	responseBodyTransformer func([]byte) ([]byte, error)
+	responseBodyTransformer func(rawBody []byte, req *Request, resp *Response) (transformedBody []byte, err error)
 }
 
 // R create a new request.
@@ -154,7 +154,7 @@ func (c *Client) GetTransport() *Transport {
 
 // SetResponseBodyTransformer set the response body transformer, which can modify the
 // response body before unmarshalled if auto-read response body is not disabled.
-func (c *Client) SetResponseBodyTransformer(fn func(body []byte) ([]byte, error)) *Client {
+func (c *Client) SetResponseBodyTransformer(fn func(rawBody []byte, req *Request, resp *Response) (transformedBody []byte, err error)) *Client {
 	c.responseBodyTransformer = fn
 	return c
 }

client_test.go

@@ -594,9 +594,12 @@ func TestEnableDumpAllAsync(t *testing.T) {
 }
 
 func TestSetResponseBodyTransformer(t *testing.T) {
-	c := tc().SetResponseBodyTransformer(func(body []byte) ([]byte, error) {
-		result, err := url.QueryUnescape(string(body))
-		return []byte(result), err
+	c := tc().SetResponseBodyTransformer(func(rawBody []byte, req *Request, resp *Response) (transformedBody []byte, err error) {
+		if resp.IsSuccess() {
+			result, err := url.QueryUnescape(string(rawBody))
+			return []byte(result), err
+		}
+		return rawBody, nil
 	})
 	user := &UserInfo{}
 	resp, err := c.R().SetResult(user).Get("/urlencode")

client_wrapper.go

@@ -600,7 +600,7 @@ func AddCommonRetryCondition(condition RetryConditionFunc) *Client {
 
 // SetResponseBodyTransformer is a global wrapper methods which delegated
 // to the default client, create a request and SetResponseBodyTransformer for request.
-func SetResponseBodyTransformer(fn func(body []byte) ([]byte, error)) *Client {
+func SetResponseBodyTransformer(fn func(rawBody []byte, req *Request, resp *Response) (transformedBody []byte, err error)) *Client {
 	return defaultClient.SetResponseBodyTransformer(fn)
 }
 

response.go

@@ -170,10 +170,11 @@ func (r *Response) ToBytes() ([]byte, error) {
 	defer r.Body.Close()
 	body, err := ioutil.ReadAll(r.Body)
 	r.setReceivedAt()
+	r.body = body
 	if err == nil && r.Request.client.responseBodyTransformer != nil {
-		body, err = r.Request.client.responseBodyTransformer(body)
+		body, err = r.Request.client.responseBodyTransformer(body, r.Request, r)
+		r.body = body
 	}
-	r.body = body
 	return body, err
 }