From 218e428036e5a3d6e76fc618bd13e179597480e3 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 23 Oct 2025 19:01:25 +0000
Subject: [PATCH] feat(go-sdk): Automatically refresh expired authentication
 tokens

The Looker Go SDK was not automatically refreshing expired authentication tokens, causing authentication to fail after one hour. This change modifies the AuthSession to proactively manage the token's lifecycle. An IsActive method was added to check the token's validity, and a Login method was added to refresh the token when needed. The Do method was updated to call Login before making any API requests, ensuring the token is always active.
---
 go/rtl/auth.go | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/go/rtl/auth.go b/go/rtl/auth.go
index d993bec7f..7c924f59f 100644
--- a/go/rtl/auth.go
+++ b/go/rtl/auth.go
@@ -39,6 +39,29 @@ func (t *transportWithHeaders) RoundTrip(req *http.Request) (*http.Response, err
 type AuthSession struct {
 	Config ApiSettings
 	Client http.Client
+	token  *oauth2.Token
+	source oauth2.TokenSource
+}
+
+func (s *AuthSession) IsActive() bool {
+	if s.token == nil {
+		return false
+	}
+	leeway := time.Second * 10
+	return s.token.Expiry.After(time.Now().Add(leeway))
+}
+
+func (s *AuthSession) Login() (*oauth2.Token, error) {
+	if s.IsActive() {
+		return s.token, nil
+	}
+
+	token, err := s.source.Token()
+	if err != nil {
+		return nil, err
+	}
+	s.token = token
+	return token, nil
 }
 
 func NewAuthSession(config ApiSettings) *AuthSession {
@@ -74,9 +97,11 @@ func NewAuthSessionWithTransport(config ApiSettings, transport http.RoundTripper
 		&http.Client{Transport: appIdHeaderTransport},
 	)
 
+	source := oauthConfig.TokenSource(ctx)
+
 	// Make use of oauth2 transport to handle token management
 	oauthTransport := &oauth2.Transport{
-		Source: oauthConfig.TokenSource(ctx),
+		Source: source,
 		// Will set "x-looker-appid" Header on all other requests
 		Base: appIdHeaderTransport,
 	}
@@ -84,11 +109,15 @@ func NewAuthSessionWithTransport(config ApiSettings, transport http.RoundTripper
 	return &AuthSession{
 		Config: config,
 		Client: http.Client{Transport: oauthTransport},
+		source: source,
 	}
 }
 
 func (s *AuthSession) Do(result interface{}, method, ver, path string, reqPars map[string]interface{}, body interface{}, options *ApiSettings) error {
-
+	_, err := s.Login()
+	if err != nil {
+		return err
+	}
 	// prepare URL
 	u := fmt.Sprintf("%s/api%s%s", s.Config.BaseUrl, ver, path)