fix: omit empty user info values

internal/service/oidc_service.go

@@ -46,6 +46,10 @@ type ClaimSet struct {
 	Sub               string   `json:"sub"`
 	Iat               int64    `json:"iat"`
 	Exp               int64    `json:"exp"`
+	Name              string   `json:"name,omitempty"`
+	Email             string   `json:"email,omitempty"`
+	PreferredUsername string   `json:"preferred_username,omitempty"`
+	Groups            []string `json:"groups,omitempty"`
 }
 
 type UserinfoResponse struct {
@@ -53,7 +57,7 @@ type UserinfoResponse struct {
 	Name              string   `json:"name"`
 	Email             string   `json:"email"`
 	PreferredUsername string   `json:"preferred_username"`
-	Groups            []string `json:"groups"`
+	Groups            []string `json:"groups,omitempty"`
 	UpdatedAt         int64    `json:"updated_at"`
 }
 
@@ -349,7 +353,7 @@ func (service *OIDCService) GetCodeEntry(c *gin.Context, codeHash string) (repos
 	return oidcCode, nil
 }
 
-func (service *OIDCService) generateIDToken(client config.OIDCClientConfig, sub string) (string, error) {
+func (service *OIDCService) generateIDToken(client config.OIDCClientConfig, user repository.OidcUserinfo, scope string) (string, error) {
 	createdAt := time.Now().Unix()
 	expiresAt := time.Now().Add(time.Duration(service.config.SessionExpiry) * time.Second).Unix()
 
@@ -367,12 +371,18 @@ func (service *OIDCService) generateIDToken(client config.OIDCClientConfig, sub
 		return "", err
 	}
 
+	userInfo := service.CompileUserinfo(user, scope)
+
 	claims := ClaimSet{
 		Iss:               service.issuer,
 		Aud:               client.ClientID,
-		Sub: sub,
+		Sub:               user.Sub,
 		Iat:               createdAt,
 		Exp:               expiresAt,
+		Name:              userInfo.Name,
+		Email:             userInfo.Email,
+		PreferredUsername: userInfo.PreferredUsername,
+		Groups:            userInfo.Groups,
 	}
 
 	payload, err := json.Marshal(claims)
@@ -397,7 +407,13 @@ func (service *OIDCService) generateIDToken(client config.OIDCClientConfig, sub
 }
 
 func (service *OIDCService) GenerateAccessToken(c *gin.Context, client config.OIDCClientConfig, sub string, scope string) (TokenResponse, error) {
-	idToken, err := service.generateIDToken(client, sub)
+	user, err := service.GetUserinfo(c, sub)
+
+	if err != nil {
+		return TokenResponse{}, err
+	}
+
+	idToken, err := service.generateIDToken(client, user, scope)
 
 	if err != nil {
 		return TokenResponse{}, err
@@ -456,9 +472,15 @@ func (service *OIDCService) RefreshAccessToken(c *gin.Context, refreshToken stri
 		return TokenResponse{}, ErrInvalidClient
 	}
 
+	user, err := service.GetUserinfo(c, entry.Sub)
+
+	if err != nil {
+		return TokenResponse{}, err
+	}
+
 	idToken, err := service.generateIDToken(config.OIDCClientConfig{
 		ClientID: entry.ClientID,
-	}, entry.Sub)
+	}, user, entry.Scope)
 
 	if err != nil {
 		return TokenResponse{}, err