Add errors package and handling

client/client.go

@@ -104,6 +104,10 @@ func (c *client) Call(service string, path string, reqval interface{}, respval i
  return fmt.Errorf("decode response: %w", err)
  }
 
+ if err, ok := respmsg.GetError(); ok {
+ return err
+ }
+
  return nil
 }
 

errors/error.go

@@ -0,0 +1,51 @@
+package errors
+
+import (
+ "bytes"
+ "encoding/base64"
+ "encoding/gob"
+ "fmt"
+ "net/http"
+ "strings"
+)
+
+type Error struct {
+ StatusCode int16
+ Detail string
+}
+
+func NewError(code int16, format string, a ...interface{}) error {
+ return &Error{
+ StatusCode: code,
+ Detail: fmt.Sprintf(format, a...),
+ }
+}
+
+// Encode transforms the error instance into a base64-encoded blob
+func (e *Error) Encode() (string, error) {
+ var b bytes.Buffer
+ enc := gob.NewEncoder(&b)
+
+ if err := enc.Encode(e); err != nil {
+ return "", err
+ }
+
+ return base64.StdEncoding.EncodeToString(b.Bytes()), nil
+}
+
+// Decode tries to decode en error from a base64-encoded string
+func Decode(str string) (*Error, error) {
+ b := strings.NewReader(str)
+ dec := gob.NewDecoder(b)
+
+ var merr Error
+ if err := dec.Decode(&merr); err != nil {
+ return nil, err
+ }
+
+ return &merr, nil
+}
+
+func (e *Error) Error() string {
+ return fmt.Sprintf("%s: %s", http.StatusText(int(e.StatusCode)), e.Detail)
+}

errors/errors.go

@@ -0,0 +1,21 @@
+package errors
+
+func BadRequest(format string, a ...string) error {
+ return NewError(400, format, a)
+}
+
+func Unauthorized(format string, a ...string) error {
+ return NewError(401, format, a)
+}
+
+func Forbidden(format string, a ...string) error {
+ return NewError(403, format, a)
+}
+
+func NotFound(format string, a ...string) error {
+ return NewError(404, format, a)
+}
+
+func InternalServerError(format string, a ...string) error {
+ return NewError(404, format, a)
+}

transport/message.go

@@ -1,5 +1,11 @@
 package transport
 
+import (
+ goerrors "errors"
+
+ "github.com/MouseHatGames/mice/errors"
+)
+
 type Message struct {
  Headers map[string]string
  Data []byte
@@ -12,5 +18,32 @@ func NewMessage() *Message {
 }
 
 func (m *Message) SetError(err error) {
- m.Headers[HeaderError] = err.Error()
+ var value string
+
+ if merr, ok := err.(*errors.Error); ok {
+ enc, err := merr.Encode()
+
+ if err != nil {
+ value = err.Error()
+ } else {
+ value = enc
+ }
+ } else {
+ value = err.Error()
+ }
+
+ m.Headers[HeaderError] = value
+}
+
+func (m *Message) GetError() (err error, hasError bool) {
+ value, ok := m.Headers[HeaderError]
+ if !ok {
+ return nil, false
+ }
+
+ if merr, err := errors.Decode(value); err != nil {
+ return merr, true
+ }
+
+ return goerrors.New(value), true
 }