node.js with express how to remove the query string from the url

Question

I have a button that is performing a get to my page and adding a filter to the query string. My code applies that filter to the grid...but the user can remove/edit that filter. Since they can see what filter was applied in the grid, I would like to remove the ?filter=blah from the query string when the page is displayed. (It might be confusing if on the page and the URL says ?filter=columnA which is correct initially, but the user removes that filter and applies a new one on columnB....but the query string still says ?filter-columnA. The grid can handle changing filters without needing a post back.) How can I do that? And if you cannot remove/update a query string, is it possible to parse it and then just redirect to the main page without the query string? Once I have the filter saved to var filter, I no longer need it in the query string.

here is the code that displays the page

exports.show = function(req, res) {
    var filter = req.query.filter;
    if (filter === null || filter === "") {
        filter = "n/a";
    }

    res.render("somepage.jade", {
            locals: {
                title: "somepage",
                filter: filter
            }
    });

};

Answer 1

Use url.parse() to get the components of your address, which is req.url. The url without the query string is stored in the pathname property.

Use express' redirect to send the new page address.

const url = require('url'); // built-in utility
res.redirect(url.parse(req.url).pathname);

Node docs for url.