MM-35332 honour config setting when extending session expiry (#17581)

Honour `ServiceSettings.ExtendSessionLengthWithActivity` config setting when extending session expiry on activity.

app/session.go

@@ -351,6 +351,10 @@ func (a *App) UpdateLastActivityAtIfNeeded(session model.Session) {
 // A new ExpiresAt is only written if enough time has elapsed since last update.
 // Returns true only if the session was extended.
 func (a *App) ExtendSessionExpiryIfNeeded(session *model.Session) bool {
+	if !*a.Srv().Config().ServiceSettings.ExtendSessionLengthWithActivity {
+		return false
+	}
+
 	if session == nil || session.IsExpired() {
 		return false
 	}

app/session_test.go

@@ -320,15 +320,22 @@ func TestApp_ExtendExpiryIfNeeded(t *testing.T) {
 	})
 
 	var tests = []struct {
+		enabled bool
 		name    string
 		session *model.Session
 	}{
-		{name: "mobile", session: &model.Session{UserId: model.NewId(), DeviceId: model.NewId(), Token: model.NewId()}},
-		{name: "SSO", session: &model.Session{UserId: model.NewId(), IsOAuth: true, Token: model.NewId()}},
-		{name: "web/LDAP", session: &model.Session{UserId: model.NewId(), Token: model.NewId()}},
+		{enabled: true, name: "mobile", session: &model.Session{UserId: model.NewId(), DeviceId: model.NewId(), Token: model.NewId()}},
+		{enabled: true, name: "SSO", session: &model.Session{UserId: model.NewId(), IsOAuth: true, Token: model.NewId()}},
+		{enabled: true, name: "web/LDAP", session: &model.Session{UserId: model.NewId(), Token: model.NewId()}},
+		{enabled: false, name: "mobile", session: &model.Session{UserId: model.NewId(), DeviceId: model.NewId(), Token: model.NewId()}},
+		{enabled: false, name: "SSO", session: &model.Session{UserId: model.NewId(), IsOAuth: true, Token: model.NewId()}},
+		{enabled: false, name: "web/LDAP", session: &model.Session{UserId: model.NewId(), Token: model.NewId()}},
 	}
+
 	for _, test := range tests {
-		t.Run(fmt.Sprintf("%s session beyond threshold should update ExpiresAt", test.name), func(t *testing.T) {
+		t.Run(fmt.Sprintf("%s session beyond threshold should update ExpiresAt based on feature enabled", test.name), func(t *testing.T) {
+			th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ServiceSettings.ExtendSessionLengthWithActivity = test.enabled })
+
 			session, err := th.App.CreateSession(test.session)
 			require.Nil(t, err)
 
@@ -337,6 +344,12 @@ func TestApp_ExtendExpiryIfNeeded(t *testing.T) {
 
 			ok := th.App.ExtendSessionExpiryIfNeeded(session)
 
+			if !test.enabled {
+				require.False(t, ok)
+				require.Equal(t, expires, session.ExpiresAt)
+				return
+			}
+
 			require.True(t, ok)
 			require.Greater(t, session.ExpiresAt, expires)
 			require.False(t, session.IsExpired())
@@ -353,7 +366,6 @@ func TestApp_ExtendExpiryIfNeeded(t *testing.T) {
 			require.Equal(t, session.ExpiresAt, storedSession.ExpiresAt)
 		})
 	}
-
 }
 
 const (