fix: incorrect jwt parsing

Author: luizfonseca

go.mod

@@ -1,6 +1,6 @@
 module github.com/luizfonseca/traefik-github-oauth-plugin
 
-go 1.21.4
+go 1.22.1
 
 require (
 	github.com/go-chi/render v1.0.3

internal/pkg/jwt/jwt.go

@@ -32,10 +32,17 @@ func ParseTokenString(tokenString, key string) (*PayloadUser, error) {
 		return nil, err
 	}
 	if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
+		teamFromClaims := claims["teams"].([]interface{})
+		teams := make([]string, len(teamFromClaims))
+
+		for i, v := range teamFromClaims {
+			teams[i] = v.(string)
+		}
+
 		return &PayloadUser{
 			Id:    claims["id"].(string),
 			Login: claims["login"].(string),
-			Teams: claims["teams"].([]string),
+			Teams: teams,
 		}, nil
 	} else {
 		return nil, fmt.Errorf("invalid token")

internal/pkg/jwt/jwt_test.go

@@ -6,6 +6,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var testTeams = []string{"team1", "team2"}
+
 const (
 	id    = "12345"
 	login = "testuser"
@@ -14,7 +16,7 @@ const (
 
 func TestGenerateJwtTokenString(t *testing.T) {
 	// execution
-	tokenString, err := GenerateJwtTokenString(id, login, key)
+	tokenString, err := GenerateJwtTokenString(id, login, testTeams, key)
 
 	// assertion
 	assert.NoError(t, err)
@@ -23,7 +25,7 @@ func TestGenerateJwtTokenString(t *testing.T) {
 
 func TestParseTokenString(t *testing.T) {
 	// setup
-	tokenString, _ := GenerateJwtTokenString(id, login, key)
+	tokenString, _ := GenerateJwtTokenString(id, login, testTeams, key)
 
 	// execution
 	payload, err := ParseTokenString(tokenString, key)
@@ -32,6 +34,7 @@ func TestParseTokenString(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, id, payload.Id)
 	assert.Equal(t, login, payload.Login)
+	assert.Equal(t, testTeams, payload.Teams)
 }
 
 func TestParseTokenString_InvalidToken(t *testing.T) {
@@ -48,7 +51,7 @@ func TestParseTokenString_InvalidToken(t *testing.T) {
 
 func TestParseTokenString_InvalidKey(t *testing.T) {
 	// setup
-	tokenString, _ := GenerateJwtTokenString(id, login, key)
+	tokenString, _ := GenerateJwtTokenString(id, login, testTeams, key)
 	invalidKey := "invalidkey"
 
 	// execution