Add sort option to mergeUrlParams

When sort option is given, mergeUrlParams
alphabetically sorts the params in ascending order (a to z).

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

@@ -75,7 +75,7 @@ export function getParameterValues(sParam, url = window.location) {
  * @param {Boolean} options.spreadArrays - split array values into separate key/value-pairs
  */
 export function mergeUrlParams(params, url, options = {}) {
-  const { spreadArrays = false } = options;
+  const { spreadArrays = false, sort = false } = options;
   const re = /^([^?#]*)(\?[^#]*)?(.*)/;
   let merged = {};
   const [, fullpath, query, fragment] = url.match(re);
@@ -108,7 +108,9 @@ export function mergeUrlParams(params, url, options = {}) {
 
   Object.assign(merged, params);
 
-  const newQuery = Object.keys(merged)
+  const mergedKeys = sort ? Object.keys(merged).sort() : Object.keys(merged);
+
+  const newQuery = mergedKeys
     .filter(key => merged[key] !== null)
     .map(key => {
       let value = merged[key];

spec/frontend/lib/utils/url_utility_spec.js

@@ -161,6 +161,15 @@ describe('URL utility', () => {
       );
     });
 
+    it('sorts params in alphabetical order with sort option', () => {
+      expect(mergeUrlParams({ c: 'c', b: 'b', a: 'a' }, 'https://host/path', { sort: true })).toBe(
+        'https://host/path?a=a&b=b&c=c',
+      );
+      expect(
+        mergeUrlParams({ alpha: 'alpha' }, 'https://host/path?op=/&foo=bar', { sort: true }),
+      ).toBe('https://host/path?alpha=alpha&foo=bar&op=%2F');
+    });
+
     describe('with spread array option', () => {
       const spreadArrayOptions = { spreadArrays: true };