add model of error for response

v1/client.go

@@ -674,7 +674,7 @@ func (c *MgClient) Error(info []byte) error {
 
 	values := data["errors"].([]interface{})
 
-	return errors.New(values[0].(string))
+	return APIError(values[0].(string))
 }
 
 // MakeTimestamp returns current unix timestamp.

v1/client_test.go

@@ -678,3 +678,11 @@ func (t *MGClientTest) Test_UploadFile() {
 	resp.CreatedAt = data.CreatedAt
 	t.Assert().Equal(resp, data)
 }
+
+func (t *MGClientTest) Test_SuccessHandleError() {
+	client := t.client()
+	handleError := client.Error([]byte(`{"errors": ["Channel not found"]}`))
+
+	t.Assert().IsType(APIError(""), handleError)
+	t.Assert().Equal(handleError.Error(), "Channel not found")
+}

v1/types.go

@@ -66,6 +66,12 @@ const (
 	OriginatorChannel
 )
 
+type APIError string
+
+func (err APIError) Error() string {
+	return string(err)
+}
+
 type ErrorType string
 
 const (