New template button takes user to new template page

for all services that only allow sending one type of notifications

tests/javascripts/templateFolderForm.test.js

@@ -1,6 +1,6 @@
 const helpers = require('./support/helpers');
 
-function setFixtures (hierarchy) {
+function setFixtures (hierarchy, newTemplateDataModules = "") {
 
   const foldersCheckboxesHTML = function (filter) {
     let count = 0;
@@ -27,7 +27,7 @@ function setFixtures (hierarchy) {
 
   }();
 
-  function controlsHTML () {
+  function controlsHTML (newTemplateDataModules) {
 
     return `<div id="sticky_template_forms">
               <button type="submit" name="operation" value="unknown" hidden=""></button>
@@ -78,7 +78,7 @@ function setFixtures (hierarchy) {
                   </div>
                 </fieldset>
               </div>
-              <div id="add_new_template_form">
+              <div id="add_new_template_form" ${newTemplateDataModules}>
                 <div class="js-will-stick-at-bottom-when-scrolling">
                   <div class="form-group ">
                     <fieldset id="add_template_by_template_type">
@@ -127,7 +127,7 @@ function setFixtures (hierarchy) {
   document.body.innerHTML = `
     <form method="post" data-module="template-folder-form">
       ${helpers.templatesAndFoldersCheckboxes(hierarchy)}
-      ${controlsHTML()}
+      ${controlsHTML(newTemplateDataModules)}
     </form>`;
 
 };
@@ -309,6 +309,37 @@ describe('TemplateFolderForm', () => {
 
   });
 
+  describe("Click 'New template' for single channel service", () => {
+    test("should redirect to new template page", () => {
+      setFixtures(hierarchy, "data-channel='sms' data-service='123'")
+      templateFolderForm = document.querySelector('form[data-module=template-folder-form]');
+
+      // start module
+      window.GOVUK.modules.start();
+
+      formControls = templateFolderForm.querySelector('#sticky_template_forms');
+
+      // reset sticky JS mocks called when the module starts
+      resetStickyMocks();
+      // add listener for url change
+      const descriptor1 = Object.getOwnPropertyDescriptor(window, 'location');
+      delete window.location
+
+      const mockCallback = jest.fn(x => {});
+
+      Object.defineProperty(window, 'location', {
+        set: mockCallback
+      });
+      // click
+      helpers.triggerEvent(formControls.querySelector('[value=add-new-template]'), 'click');
+      // expect url to change
+      expect(mockCallback).toHaveBeenCalledWith("/services/123/templates/add-sms")
+
+      setFixtures(hierarchy)
+      resetStickyMocks()
+    });
+  })
+
   describe("Clicking 'New template'", () => {
 
     beforeEach(() => {