JWT expired with fetch javascript

Question

What is the best way with pure javascript fetch function to check if JWT has expired that is being passed in authorization header before making a request to get data?

const headers = new Headers({
    'Content-Type': 'application/json',
    Authorization: 'Bearer GrabbedFromParamQueryString'
});

const settings = {
    method: 'GET',
    headers: headers
};

fetch('/info/user, settings).then(response => {
    console.log(response.json());
});

I know in jQuery you can do a precheck if it has expired then generate a new token then continue with the original request. Is there something like that with Javascript fetch if so how?

Any help would be appreciated.

Answer 1

I was able to achieve this by checking the status of the response which gave me the answer if it was expired or not. Once I had that information created a handled error function and do the next set of action to grab the new refresh and token id.

Answer 2

try

       console.log(response.json());
       if(response.msg=== "Token is expired"){
           alert('token is already expired, login again')
          }
});

Atleast thats what I do for jwt extended tokens , because they generate such a response. so in your case, If you used some other naming type like "message" please go ahead and use it to loop through your response. I hope its been of help.