Check login succeeded

[wiktor000]

Hello How to check login succeeded I try `

const login = require("facebook-chat-api");
var email = req.query.email
var pass = req.query.pass
login({email: email, password: pass}, (err, api) => {
    if(err) return console.error(err);

    switch(err)
{
	case null:
	console.log("ok");
	break;
default:
console.log("bad pass or login");

}
	`

but working only when the data is correct

[BadAimWeeb]

just check if function returned api like this:

const login = require("facebook-chat-api");
var email = req.query.email
var pass = req.query.pass
login({email: email, password: pass}, (err, api) => {
    if (!api) { 
        console.log("bad pass or login");
    } else {
        console.log("ok");
    }
    if(err) return console.error(err);
}

[Schmavery]

Isn't this what if (err) return console.error(err); is doing??