Simpe script that allows you to keep all query parameters from URL

keep-query-params.js

function setParameter(key, value) {
    if (history.pushState) {
        let parameters = new URLSearchParams(window.location.search);
        parameters.set(key, value);

        let newUrl = window.location.protocol + "//" + window.location.host + window.location.pathname + '?' + parameters.toString();

        window.history.pushState({
            path: newUrl
        }, '', newUrl);
    }
}

function unsetParameter(key) {
    if (history.pushState) {
        let parameters = new URLSearchParams(window.location.search);
        parameters.delete(key);

        let newUrl = window.location.protocol + "//" + window.location.host + window.location.pathname + '?' + parameters.toString();
        window.history.pushState({
            path: newUrl
        }, '', newUrl);
    }
}

function getParameter(key) {
    if (history.pushState) {
        let parameters = new URLSearchParams(window.location.search);
        return parameters.get(key);
    }
}


function requestData(existingParameters) {
    let newData = {};

    if ('' !== $('#input').val().trim()) {
        newParameters.input = $('#input').val().trim();
        setGetParam('input', newParameters.input);
    } else {
        unsetGetParam('input');
    }

    return newParameters;
}