Allow conditions to have a replacement URL in filtered search

This allows for conditions to override the previously set URL with
a new URL. For merge requests, we will be replacing WIP with draft
which this will allow.

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/227414

app/assets/javascripts/filtered_search/filtered_search_manager.js

@@ -743,7 +743,7 @@ export default class FilteredSearchManager {
       let tokenPath = '';
 
       if (condition) {
-        tokenPath = condition.url;
+        tokenPath = condition.replacementUrl || condition.url;
       } else {
         let tokenValue = token.value;
 

spec/frontend/filtered_search/filtered_search_manager_spec.js

@@ -225,6 +225,26 @@ describe('Filtered Search Manager', () => {
       manager.search();
     });
 
+    it('should use replacement URL for condition', done => {
+      tokensContainer.innerHTML = FilteredSearchSpecHelper.createTokensContainerHTML(
+        FilteredSearchSpecHelper.createFilterVisualTokenHTML('milestone', '=', '13', true),
+      );
+
+      visitUrl.mockImplementation(url => {
+        expect(url).toEqual(`${defaultParams}&milestone_title=replaced`);
+        done();
+      });
+
+      manager.filteredSearchTokenKeys.conditions.push({
+        url: 'milestone_title=13',
+        replacementUrl: 'milestone_title=replaced',
+        tokenKey: 'milestone',
+        value: '13',
+        operator: '=',
+      });
+      manager.search();
+    });
+
     it('removes duplicated tokens', done => {
       tokensContainer.innerHTML = FilteredSearchSpecHelper.createTokensContainerHTML(`
         ${FilteredSearchSpecHelper.createFilterVisualTokenHTML('label', '=', '~bug')}