How to know if a given user is already logged in with MSAL?

Question

With msal.js library (The Microsoft Authentication Library), which is the way to know if a given user is already logged in? My intention is to avoid to show login pop-up if the user's credentials are already saved in browser's storage

My current approach:

function isUserLoggedIn(username) {
 const agent = msal.UserAgentApplication(...);
 const user = agent.getUser();
 return user != null && user.displayableId === username);
}

But I'm not sure if I have to check if the user credentials are outdated/expired. Which is the proper way to go?

Answer 1

From MSAL samples, they were checking this way:

let isLoggedIn = this.authService.instance.getAllAccounts().length > 0;