client support SetCommonError

client.go

@@ -16,6 +16,7 @@ import (
 	"net/http/cookiejar"
 	urlpkg "net/url"
 	"os"
+	"reflect"
 	"strings"
 	"time"
 )
@@ -36,23 +37,23 @@ var defaultClient *Client = C()
 
 // Client is the req's http client.
 type Client struct {
-	BaseURL               string
-	PathParams            map[string]string
-	QueryParams           urlpkg.Values
-	Headers               http.Header
-	Cookies               []*http.Cookie
-	FormData              urlpkg.Values
-	DebugLog              bool
-	AllowGetMethodPayload bool
-
+	BaseURL                 string
+	PathParams              map[string]string
+	QueryParams             urlpkg.Values
+	Headers                 http.Header
+	Cookies                 []*http.Cookie
+	FormData                urlpkg.Values
+	DebugLog                bool
+	AllowGetMethodPayload   bool
+	trace                   bool
+	disableAutoReadResponse bool
+	commonErrorType         reflect.Type
 	retryOption             *retryOption
 	jsonMarshal             func(v interface{}) ([]byte, error)
 	jsonUnmarshal           func(data []byte, v interface{}) error
 	xmlMarshal              func(v interface{}) ([]byte, error)
 	xmlUnmarshal            func(data []byte, v interface{}) error
-	trace                   bool
 	outputDirectory         string
-	disableAutoReadResponse bool
 	scheme                  string
 	log                     Logger
 	t                       *Transport
@@ -72,6 +73,15 @@ func (c *Client) R() *Request {
 	}
 }
 
+// SetCommonError set the common result that response body will be unmarshalled to
+// if it is an error response ( status `code >= 400`).
+func (c *Client) SetCommonError(err interface{}) *Client {
+	if err != nil {
+		c.commonErrorType = util.GetType(err)
+	}
+	return c
+}
+
 // SetCommonFormDataFromValues set the form data from url.Values for all requests
 // which request method allows payload.
 func (c *Client) SetCommonFormDataFromValues(data urlpkg.Values) *Client {

client_wrapper.go

@@ -10,6 +10,12 @@ import (
 	"time"
 )
 
+// SetCommonError is a global wrapper methods which delegated
+// to the default client's SetCommonError.
+func SetCommonError(err interface{}) *Client {
+	return defaultClient.SetCommonError(err)
+}
+
 // SetCommonFormDataFromValues is a global wrapper methods which delegated
 // to the default client's SetCommonFormDataFromValues.
 func SetCommonFormDataFromValues(data url.Values) *Client {

client_wrapper_test.go

@@ -23,6 +23,7 @@ func TestGlobalWrapper(t *testing.T) {
 	form.Add("test", "test")
 
 	assertAllNotNil(t,
+		SetCommonError(nil),
 		SetCookieJar(nil),
 		SetDialTLS(nil),
 		SetDial(nil),

internal/util/util.go

@@ -27,6 +27,11 @@ func GetPointer(v interface{}) interface{} {
 	return reflect.New(vv.Type()).Interface()
 }
 
+// GetType return the underlying type.
+func GetType(v interface{}) reflect.Type {
+	return reflect.Indirect(reflect.ValueOf(v)).Type()
+}
+
 // CutString slices s around the first instance of sep,
 // returning the text before and after sep.
 // The found result reports whether sep appears in s.

middleware.go

@@ -11,6 +11,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"time"
 )
@@ -280,10 +281,18 @@ func parseResponseBody(c *Client, r *Response) (err error) {
 			r.result = r.Request.Result
 		}
 	}
-	if r.Request.Error != nil && r.IsError() {
-		err = unmarshalBody(c, r, r.Request.Error)
-		if err == nil {
-			r.error = r.Request.Error
+	if r.IsError() {
+		if r.Request.Error != nil {
+			err = unmarshalBody(c, r, r.Request.Error)
+			if err == nil {
+				r.error = r.Request.Error
+			}
+		} else if c.commonErrorType != nil {
+			e := reflect.New(c.commonErrorType).Interface()
+			err = unmarshalBody(c, r, e)
+			if err == nil {
+				r.error = e
+			}
 		}
 	}
 	return

request_test.go

@@ -687,6 +687,15 @@ func testError(t *testing.T, c *Client) {
 		Get("/search")
 	assertIsError(t, resp, err)
 	assertEqual(t, 10001, errMsg.ErrorCode)
+
+	c.SetCommonError(&errMsg)
+	resp, err = c.R().
+		SetQueryParam("username", "").
+		Get("/search")
+	assertIsError(t, resp, err)
+	em, ok := resp.Error().(*ErrorMessage)
+	assertEqual(t, true, ok)
+	assertEqual(t, 10000, em.ErrorCode)
 }
 
 func TestForm(t *testing.T) {