diff --git a/assets/static/querystring.js b/assets/static/querystring.js
index 5cd83cc3b..cc330604e 100644
--- a/assets/static/querystring.js
+++ b/assets/static/querystring.js
@@ -1,54 +1,49 @@
-/* exported QueryString */
-var QueryString = (function() {
+const $ = require("jquery");
 
-    var parse = function() {
-        var vars = [],
-            hash;
-        var q = document.URL.split("?")[1];
-        if (q !== undefined) {
-            q = q.split("&");
-            for (var i = 0; i < q.length; i++) {
-                hash = q[i].split("=");
-                vars[hash[0]] = hash.slice(1).join("=");
-            }
+function parse() {
+    var vars = {},
+        hash;
+    var q = document.URL.split("?")[1];
+    if (q !== undefined) {
+        q = q.split("&");
+        for (var i = 0; i < q.length; i++) {
+            hash = q[i].split("=");
+            vars[hash[0]] = hash.slice(1).join("=");
         }
-        return vars;
-    };
+    }
+    return vars;
+}
 
-    var update = function(key, value) {
-        /* https://gist.github.com/excalq/2961415 */
-        var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
-            urlQueryString = document.location.search,
-            newParam = key + "=" + value,
-            params = "?" + newParam;
+function update(key, value) {
+    /* https://gist.github.com/excalq/2961415 */
+    var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
+        urlQueryString = document.location.search,
+        newParam = key + "=" + value,
+        params = "?" + newParam;
 
-        // If the "search" string exists, then build params from it
-        if (urlQueryString) {
-            var keyRegex = new RegExp("([?&])" + key + "[^&]*");
+    // If the "search" string exists, then build params from it
+    if (urlQueryString) {
+        var keyRegex = new RegExp("([?&])" + key + "[^&]*");
 
-            // If param exists already, update it
-            if (urlQueryString.match(keyRegex) !== null) {
-                params = urlQueryString.replace(keyRegex, "$1" + newParam);
-            } else { // Otherwise, add it to end of query string
-                params = urlQueryString + "&" + newParam;
-            }
+        // If param exists already, update it
+        if (urlQueryString.match(keyRegex) !== null) {
+            params = urlQueryString.replace(keyRegex, "$1" + newParam);
+        } else { // Otherwise, add it to end of query string
+            params = urlQueryString + "&" + newParam;
         }
-        window.history.replaceState({}, "", baseUrl + params);
-    };
+    }
+    window.history.replaceState({}, "", baseUrl + params);
+}
 
-    var remove = function(key) {
-        var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
-            q = QueryString.Parse();
-        if (q[key] !== undefined) {
-            delete q[key];
-            window.history.replaceState({}, "", baseUrl + "?" + $.param(q));
-        }
-    };
+function remove(key) {
+    var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
+        q = parse();
+    if (q[key] !== undefined) {
+        delete q[key];
+        window.history.replaceState({}, "", baseUrl + "?" + $.param(q));
+    }
+}
 
-    return {
-        Parse: parse,
-        Set: update,
-        Remove: remove
-    };
-
-}());
+exports.parse = parse;
+exports.update = update;
+exports.remove = remove;
diff --git a/assets/static/querystring.test.js b/assets/static/querystring.test.js
new file mode 100644
index 000000000..1252b0cf9
--- /dev/null
+++ b/assets/static/querystring.test.js
@@ -0,0 +1,23 @@
+const querystring = require("./querystring");
+
+test("querystring parse()", () => {
+    expect(querystring.parse()).toEqual({});
+    Object.defineProperty(document, "URL", {
+        value: "http://example.com?foo=bar",
+        configurable: true,
+    });
+    expect(querystring.parse()).toEqual({"foo": "bar"});
+});
+
+test("querystring update()", () => {
+    Object.defineProperty(document, "URL", {
+        value: "http://example.com?foo=bar",
+        configurable: true,
+    });
+    expect(querystring.parse()).toEqual({"foo": "bar"});
+    /*
+    FIXME disabled as it requires mocking browser history
+    querystring.update("foo", "notbar");
+    expect(querystring.parse()).toEqual({"foo": "notbar"});
+    */
+});