1 files changed, 33 insertions, 4 deletions
diff --git a/client/go/internal/cli/auth/zts/zts_test.go b/client/go/internal/cli/auth/zts/zts_test.go
index 1c75a94ee03..15c60ed46d7 100644
--- a/client/go/internal/cli/auth/zts/zts_test.go
+++ b/client/go/internal/cli/auth/zts/zts_test.go
@@ -2,28 +2,57 @@ package zts
 
 import (
 	"testing"
+	"time"
 
 	"github.com/vespa-engine/vespa/client/go/internal/mock"
 )
 
+type manualClock struct{ t time.Time }
+
+func (c *manualClock) now() time.Time          { return c.t }
+func (c *manualClock) advance(d time.Duration) { c.t = c.t.Add(d) }
+
 func TestAccessToken(t *testing.T) {
 	httpClient := mock.HTTPClient{}
 	client, err := NewClient(&httpClient, "vespa.vespa", "http://example.com")
 	if err != nil {
 		t.Fatal(err)
 	}
+	clock := &manualClock{t: time.Now()}
+	client.now = clock.now
 	httpClient.NextResponseString(400, `{"message": "bad request"}`)
 	_, err = client.AccessToken()
 	if err == nil {
 		t.Fatal("want error for non-ok response status")
 	}
-	httpClient.NextResponseString(200, `{"access_token": "foo bar"}`)
+	httpClient.NextResponseString(200, `{"access_token": "foo", "expires_in": 3600}`)
 	token, err := client.AccessToken()
 	if err != nil {
 		t.Fatal(err)
 	}
-	want := "foo bar"
-	if token != want {
-		t.Errorf("got %q, want %q", token, want)
+
+	// Token is cached
+	expiresAt := clock.now().Add(time.Hour)
+	assertToken(t, Token{Value: "foo", ExpiresAt: expiresAt}, token)
+	clock.advance(54 * time.Minute)
+	assertToken(t, Token{Value: "foo", ExpiresAt: expiresAt}, token)
+
+	// Token is renewed when nearing expiry
+	clock.advance(time.Minute + time.Second)
+	httpClient.NextResponseString(200, `{"access_token": "bar", "expires_in": 1800}`)
+	token, err = client.AccessToken()
+	if err != nil {
+		t.Fatal(err)
+	}
+	expiresAt = clock.now().Add(30 * time.Minute)
+	assertToken(t, Token{Value: "bar", ExpiresAt: expiresAt}, token)
+}
+
+func assertToken(t *testing.T, want, got Token) {
+	if want.Value != got.Value {
+		t.Errorf("got Value=%q, want %q", got.Value, want.Value)
+	}
+	if want.ExpiresAt != got.ExpiresAt {
+		t.Errorf("got ExpiresAt=%s, want %s", got.ExpiresAt, want.ExpiresAt)
 	}
 }