fix #232: use %w to wrap error

CHANGELOG.md

@@ -1,8 +1,12 @@
 # Change Log
 
+## v2.7.1
+
+- `[FIX]` [#232](https://github.com/huandu/facebook/issues/232) Fix incorrect error wrapping. Thanks, [@AnatolyRugalev](https://github.com/AnatolyRugalev).
+
 ## v2.7.0
 
-- `[NEW]` [#211](https://github.com/huandu/facebook/pull/211) Make session on app configurable. Thank [Spazzy757](https://github.com/Spazzy757) for your PR.
+- `[NEW]` [#211](https://github.com/huandu/facebook/pull/211) Make session on app configurable. Thank [@Spazzy757](https://github.com/Spazzy757) for your PR.
 
 ## v2.6.0
 

app.go

@@ -67,21 +67,21 @@ func (app *App) ParseSignedRequest(signedRequest string) (res Result, err error)
 	sig, e1 := base64.RawURLEncoding.DecodeString(strs[0])
 
 	if e1 != nil {
-		err = fmt.Errorf("facebook: fail to decode signed request sig with error %v", e1)
+		err = fmt.Errorf("facebook: fail to decode signed request sig with error %w", e1)
 		return
 	}
 
 	payload, e2 := base64.RawURLEncoding.DecodeString(strs[1])
 
 	if e2 != nil {
-		err = fmt.Errorf("facebook: fail to decode signed request payload with error is %v", e2)
+		err = fmt.Errorf("facebook: fail to decode signed request payload with error is %w", e2)
 		return
 	}
 
 	err = json.Unmarshal(payload, &res)
 
 	if err != nil {
-		err = fmt.Errorf("facebook: signed request payload is not a valid json string with error %v", err)
+		err = fmt.Errorf("facebook: signed request payload is not a valid json string with error %w", err)
 		return
 	}
 
@@ -142,7 +142,7 @@ func (app *App) ParseCodeInfo(code, machineID string) (token string, expires int
 	})
 
 	if err != nil {
-		err = fmt.Errorf("facebook: fail to parse facebook response with error %v", err)
+		err = fmt.Errorf("facebook: fail to parse facebook response with error %w", err)
 		return
 	}
 
@@ -190,7 +190,7 @@ func (app *App) ExchangeToken(accessToken string) (token string, expires int, er
 	})
 
 	if err != nil {
-		err = fmt.Errorf("fail to parse facebook response with error %v", err)
+		err = fmt.Errorf("fail to parse facebook response with error %w", err)
 		return
 	}
 
@@ -230,7 +230,7 @@ func (app *App) GetCode(accessToken string) (code string, err error) {
 	})
 
 	if err != nil {
-		err = fmt.Errorf("facebook: fail to get code from facebook with error %v", err)
+		err = fmt.Errorf("facebook: fail to get code from facebook with error %w", err)
 		return
 	}
 

result.go

@@ -328,19 +328,19 @@ func getValueField(value reflect.Value, fields []string) reflect.Value {
 //
 // Examples:
 //
-//     type Foo struct {
-//         // "id" must exist in response. note the leading comma.
-//         Id string `facebook:",required"`
+//	type Foo struct {
+//	    // "id" must exist in response. note the leading comma.
+//	    Id string `facebook:",required"`
 //
-//         // use "name" as field name in response.
-//         TheName string `facebook:"name"`
+//	    // use "name" as field name in response.
+//	    TheName string `facebook:"name"`
 //
-//         // the "json" key also works as expected.
-//         Key string `json:"my_key"`
+//	    // the "json" key also works as expected.
+//	    Key string `json:"my_key"`
 //
-//         // if both "facebook" and "json" key are set, the "facebook" key is used.
-//         Value string `facebook:"value" json:"shadowed"`
-//     }
+//	    // if both "facebook" and "json" key are set, the "facebook" key is used.
+//	    Value string `facebook:"value" json:"shadowed"`
+//	}
 //
 // To change default behavior, set a struct tag `facebook:",required"` to fields
 // should not be missing.
@@ -388,12 +388,13 @@ func (res Result) DecodeField(field string, v interface{}) error {
 // Err returns an error if Result is a Graph API error.
 //
 // The returned error can be converted to Error by type assertion.
-//     err := res.Err()
-//     if err != nil {
-//         if e, ok := err.(*Error); ok {
-//             // read more details in e.Message, e.Code and e.Type
-//         }
-//     }
+//
+//	err := res.Err()
+//	if err != nil {
+//	    if e, ok := err.(*Error); ok {
+//	        // read more details in e.Message, e.Code and e.Type
+//	    }
+//	}
 //
 // For more information about Graph API Errors, see
 // https://developers.facebook.com/docs/reference/api/errors/
@@ -420,13 +421,14 @@ func (res Result) Err() error {
 //
 // Facebook uses following JSON structure to response paging information.
 // If "data" doesn't present in Result, Paging will return error.
-//     {
-//         "data": [...],
-//         "paging": {
-//             "previous": "https://graph.facebook.com/...",
-//             "next": "https://graph.facebook.com/..."
-//         }
-//     }
+//
+//	{
+//	    "data": [...],
+//	    "paging": {
+//	        "previous": "https://graph.facebook.com/...",
+//	        "next": "https://graph.facebook.com/..."
+//	    }
+//	}
 func (res Result) Paging(session *Session) (*PagingResult, error) {
 	return newPagingResult(session, res)
 }
@@ -614,7 +616,7 @@ func decodeField(val reflect.Value, field reflect.Value, fullName string) error
 		data, err := json.Marshal(val.Interface())
 
 		if err != nil {
-			return fmt.Errorf("facebook: fail to marshal value for field '%v' with error %v", fullName, err)
+			return fmt.Errorf("facebook: fail to marshal value for field '%v' with error %w", fullName, err)
 		}
 
 		return unmarshaler.UnmarshalJSON(data)

session.go

@@ -476,7 +476,7 @@ func (session *Session) sendPostRequest(uri string, params Params, res interface
 	mime, err := params.Encode(buf)
 
 	if err != nil {
-		return nil, fmt.Errorf("facebook: cannot encode POST params; %v", err)
+		return nil, fmt.Errorf("facebook: cannot encode POST params; %w", err)
 	}
 
 	request, err := http.NewRequest("POST", uri, buf)
@@ -502,7 +502,7 @@ func (session *Session) sendOauthRequest(uri string, params Params) (Result, err
 	mime, err := params.Encode(buf)
 
 	if err != nil {
-		return nil, fmt.Errorf("facebook: cannot encode POST params; %v", err)
+		return nil, fmt.Errorf("facebook: cannot encode POST params; %w", err)
 	}
 
 	request, err := http.NewRequest("POST", urlStr, buf)
@@ -562,7 +562,7 @@ func (session *Session) sendRequest(request *http.Request) (response *http.Respo
 	}
 
 	if err != nil {
-		err = fmt.Errorf("facebook: cannot reach facebook server; %v", err)
+		err = fmt.Errorf("facebook: cannot reach facebook server; %w", err)
 		return
 	}
 
@@ -571,7 +571,7 @@ func (session *Session) sendRequest(request *http.Request) (response *http.Respo
 	response.Body.Close()
 
 	if err != nil {
-		err = fmt.Errorf("facebook: cannot read facebook response; %v", err)
+		err = fmt.Errorf("facebook: cannot read facebook response; %w", err)
 	}
 
 	data = buf.Bytes()