What happens if you don't resolve or reject a promise?

Question

I have a scenario where I am returning a promise. The promise is basically triggered by an ajax request.

On rejecting the promise it shows an error dialog that there

Answer 1

As others stated it's true that it's not really an issue if you don't resolve/reject a promise. Anyway I would solve your problem a bit different:

function makeRequest(ur,params) {

    return new Promise(function(resolve,reject) {

        fetch(url,params)
        .then((response) => {

            let status = response.status;

            if (status >= 200 && status < 300) {
                response.json().then((data) => {
                    resolve(data);
                })
            }
            else {
                reject(response);
            }
        })
    });
}

makeRequest().then(function success(data) {
   //...
}, function error(response) {
    if (response.status === 401) {
        redirectToLoginPage();
    }
    else {
        response.json().then((error) => {
            if (!error.message) {
                error.message = constants.SERVER_ERROR;
            }

            //do sth. with error
        });
    } 
});

That means I would reject every bad response state and then handle this in your error handler of your makeRequest.