Improve session error reporting

irmaclient/session.go

@@ -322,7 +322,14 @@ func (session *session) KeyshareBlocked(duration int) {
 }
 
 func (session *session) KeyshareError(err error) {
-	session.fail(&irma.SessionError{ErrorType: irma.ErrorKeyshare, Err: err})
+	var serr *irma.SessionError
+	var ok bool
+	if serr, ok = err.(*irma.SessionError); !ok {
+		serr = &irma.SessionError{ErrorType: irma.ErrorKeyshare, Err: err}
+	} else {
+		serr.ErrorType = irma.ErrorKeyshare
+	}
+	session.fail(serr)
 }
 
 func (session *session) KeysharePin() {

messages.go

@@ -3,10 +3,13 @@ package irma
 import (
 	"encoding/base64"
 	"encoding/json"
-	"fmt"
 	"math/big"
 	"strings"
 
+	"bytes"
+
+	"fmt"
+
 	"github.com/go-errors/errors"
 )
 
@@ -27,8 +30,9 @@ type SessionError struct {
 	Err error
 	ErrorType
 	*ApiError
-	Info   string
-	Status int
+	Info          string
+	Status        int
+	StatusMessage string
 }
 
 // ApiError is an error message returned by the API server on errors.
@@ -40,6 +44,14 @@ type ApiError struct {
 	Stacktrace  string `json:"stacktrace"`
 }
 
+func (err *ApiError) Error() string {
+	var msg string
+	if err.Message != "" {
+		msg = fmt.Sprintf(" (%s)", err.Message)
+	}
+	return fmt.Sprintf("%s%s: %s", err.ErrorName, msg, err.Description)
+}
+
 // Qr contains the data of an IRMA session QR (as generated by irma_js),
 // suitable for NewSession().
 type Qr struct {
@@ -110,10 +122,28 @@ const (
 )
 
 func (e *SessionError) Error() string {
+	var buffer bytes.Buffer
+	typ := e.ErrorType
+	if typ == "" {
+		typ = ErrorType("unknown")
+	}
+
+	buffer.WriteString("Error type: ")
+	buffer.WriteString(string(typ))
 	if e.Err != nil {
-		return fmt.Sprintf("%s: %s", string(e.ErrorType), e.Err.Error())
+		buffer.WriteString("\nDescription: ")
+		buffer.WriteString(e.Err.Error())
 	}
-	return string(e.ErrorType)
+	if e.Status != 200 && e.StatusMessage != "" {
+		buffer.WriteString("\nConnection: ")
+		buffer.WriteString(e.StatusMessage)
+	}
+	if e.ApiError != nil {
+		buffer.WriteString("\nIRMA server error: ")
+		buffer.WriteString(e.ApiError.Error())
+	}
+
+	return buffer.String()
 }
 
 func JwtDecode(jwt string, body interface{}) error {

transport.go

@@ -110,18 +110,18 @@ func (transport *HTTPTransport) jsonRequest(url string, method string, result in
 
 	body, err := ioutil.ReadAll(res.Body)
 	if err != nil {
-		return &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode}
+		return &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode, StatusMessage: res.Status}
 	}
 	if res.StatusCode != 200 {
 		apierr := &ApiError{}
 		err = json.Unmarshal(body, apierr)
 		if err != nil || apierr.ErrorName == "" { // Not an ApiErrorMessage
-			return &SessionError{ErrorType: ErrorServerResponse, Status: res.StatusCode}
+			return &SessionError{ErrorType: ErrorServerResponse, Status: res.StatusCode, StatusMessage: res.Status}
 		}
 		if verbose {
 			fmt.Printf("ERROR: %+v\n", apierr)
 		}
-		return &SessionError{ErrorType: ErrorApi, Status: res.StatusCode, ApiError: apierr}
+		return &SessionError{ErrorType: ErrorApi, Status: res.StatusCode, ApiError: apierr, StatusMessage: res.Status}
 	}
 
 	if verbose {
@@ -132,7 +132,7 @@ func (transport *HTTPTransport) jsonRequest(url string, method string, result in
 	} else {
 		err = json.Unmarshal(body, result)
 		if err != nil {
-			return &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode}
+			return &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode, StatusMessage: res.Status}
 		}
 	}
 
@@ -146,7 +146,7 @@ func (transport *HTTPTransport) GetBytes(url string) ([]byte, error) {
 	}
 	b, err := ioutil.ReadAll(res.Body)
 	if err != nil {
-		return nil, &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode}
+		return nil, &SessionError{ErrorType: ErrorServerResponse, Err: err, Status: res.StatusCode, StatusMessage: res.Status}
 	}
 	return b, nil
 }