Moved URL utility methods into es modules

app/assets/javascripts/lib/utils/url_utility.js

-/* eslint-disable func-names, space-before-function-paren, wrap-iife, no-var, no-param-reassign, no-cond-assign, one-var, one-var-declaration-per-line, no-void, guard-for-in, no-restricted-syntax, prefer-template, quotes, max-len */
-
-var base;
-var w = window;
-if (w.gl == null) {
-  w.gl = {};
-}
-if ((base = w.gl).utils == null) {
-  base.utils = {};
-}
 // Returns an array containing the value(s) of the
 // of the key passed as an argument
-w.gl.utils.getParameterValues = function(sParam) {
-  var i, sPageURL, sParameterName, sURLVariables, values;
-  sPageURL = decodeURIComponent(window.location.search.substring(1));
-  sURLVariables = sPageURL.split('&');
-  sParameterName = void 0;
-  values = [];
-  i = 0;
-  while (i < sURLVariables.length) {
-    sParameterName = sURLVariables[i].split('=');
+export function getParameterValues(sParam) {
+  const sPageURL = decodeURIComponent(window.location.search.substring(1));
+
+  return sPageURL.split('&').reduce((acc, urlParam) => {
+    const sParameterName = urlParam.split('=');
+
     if (sParameterName[0] === sParam) {
-      values.push(sParameterName[1].replace(/\+/g, ' '));
+      acc.push(sParameterName[1].replace(/\+/g, ' '));
     }
-    i += 1;
-  }
-  return values;
-};
+
+    return acc;
+  }, []);
+}
+
 // @param {Object} params - url keys and value to merge
 // @param {String} url
-w.gl.utils.mergeUrlParams = function(params, url) {
-  var lastChar, newUrl, paramName, paramValue, pattern;
-  newUrl = decodeURIComponent(url);
-  for (paramName in params) {
-    paramValue = params[paramName];
-    pattern = new RegExp("\\b(" + paramName + "=).*?(&|$)");
-    if (paramValue == null) {
-      newUrl = newUrl.replace(pattern, '');
+export function mergeUrlParams(params, url) {
+  let newUrl = Object.keys(params).reduce((accParam, paramName) => {
+    const paramValue = params[paramName];
+    const pattern = new RegExp(`\\b(${paramName}=).*?(&|$)`);
+    let acc = accParam;
+
+    if (paramValue === null) {
+      acc = acc.replace(pattern, '');
     } else if (url.search(pattern) !== -1) {
-      newUrl = newUrl.replace(pattern, "$1" + paramValue + "$2");
+      acc = acc.replace(pattern, `$1${paramValue}$2`);
     } else {
-      newUrl = "" + newUrl + (newUrl.indexOf('?') > 0 ? '&' : '?') + paramName + "=" + paramValue;
-    }
+      acc = `${accParam}${accParam.indexOf('?') > 0 ? '&' : '?'}${paramName}=${paramValue}`;
     }
+
+    return acc;
+  }, decodeURIComponent(url));
+
   // Remove a trailing ampersand
-  lastChar = newUrl[newUrl.length - 1];
+  const lastChar = newUrl[newUrl.length - 1];
+
   if (lastChar === '&') {
     newUrl = newUrl.slice(0, -1);
   }
+
   return newUrl;
-};
-// removes parameter query string from url. returns the modified url
-w.gl.utils.removeParamQueryString = function(url, param) {
-  var urlVariables, variables;
-  url = decodeURIComponent(url);
-  urlVariables = url.split('&');
-  return ((function() {
-    var j, len, results;
-    results = [];
-    for (j = 0, len = urlVariables.length; j < len; j += 1) {
-      variables = urlVariables[j];
-      if (variables.indexOf(param) === -1) {
-        results.push(variables);
-      }
-    }
-    return results;
-  })()).join('&');
-};
-w.gl.utils.removeParams = (params) => {
+}
+
+export function removeParamQueryString(url, param) {
+  const decodedUrl = decodeURIComponent(url);
+  const urlVariables = decodedUrl.split('&');
+
+  return urlVariables.filter(variable => variable.indexOf(param) === -1).join('&');
+}
+
+export function removeParams(params) {
   const url = document.createElement('a');
   url.href = window.location.href;
+
   params.forEach((param) => {
-    url.search = w.gl.utils.removeParamQueryString(url.search, param);
+    url.search = removeParamQueryString(url.search, param);
   });
+
   return url.href;
-};
-w.gl.utils.getLocationHash = function(url) {
-  var hashIndex;
-  if (typeof url === 'undefined') {
-    // Note: We can't use window.location.hash here because it's
-    // not consistent across browsers - Firefox will pre-decode it
-    url = window.location.href;
-  }
-  hashIndex = url.indexOf('#');
-  return hashIndex === -1 ? null : url.substring(hashIndex + 1);
-};
+}
 
-w.gl.utils.refreshCurrentPage = () => gl.utils.visitUrl(window.location.href);
+export function getLocationHash(url) {
+  const hashIndex = window.location.href.indexOf('#');
+
+  return hashIndex === -1 ? null : url.substring(hashIndex + 1);
+}
 
-// eslint-disable-next-line import/prefer-default-export
 export function visitUrl(url, external = false) {
   if (external) {
     // Simulate `target="blank" rel="noopener noreferrer"`
@@ -100,6 +79,10 @@ export function visitUrl(url, external = false) {
   }
 }
 
+export function refreshCurrentPage() {
+  visitUrl(window.location.href);
+}
+
 export function redirectTo(url) {
   return window.location.assign(url);
 }
@@ -107,5 +90,11 @@ export function redirectTo(url) {
 window.gl = window.gl || {};
 window.gl.utils = {
   ...(window.gl.utils || {}),
+  mergeUrlParams,
+  getLocationHash,
+  getParameterValues,
+  redirectTo,
+  refreshCurrentPage,
+  removeParams,
   visitUrl,
 };