Office.js nullifies browser history functions breaking history usage

This works for me – cache the objects before office-js deletes them:

<script type="text/javascript">
    // Office js deletes window.history.pushState and window.history.replaceState. Cache them and restore them
    window._historyCache = {
        replaceState: window.history.replaceState,
        pushState: window.history.pushState
    };
</script>

<script type="text/javascript" src="https://appsforoffice.microsoft.com/lib/1/hosted/office.js"></script>

<script type="text/javascript">
    // Office js deletes window.history.pushState and window.history.replaceState. Restore them
    window.history.replaceState = window._historyCache.replaceState;
    window.history.pushState = window._historyCache.pushState;
</script>