Update tests to use most recent jest and supporting libraries

tests/javascripts/support/helpers.js

@@ -23,5 +23,5 @@ exports.templatesAndFoldersCheckboxes = html.templatesAndFoldersCheckboxes;
 exports.element = elements.element;
 exports.WindowMock = rendering.WindowMock;
 exports.ScreenMock = rendering.ScreenMock;
-exports.spyOnFormSubmit = forms.spyOnFormSubmit;
+exports.spyOnFormSubmitEventPrevention = forms.spyOnFormSubmitEventPrevention;
 exports.getFormDataFromPairs = utilities.getFormDataFromPairs;

tests/javascripts/support/helpers/forms.js

@@ -1,6 +1,6 @@
 
-// helper for spying on the submit method on a form element
-// JSDOM's implementation of submit just wraps a 'not implemented' error so we need to mock that to track calls to it
+// helper for spying on the submit method on a form element, via the event's `preventDefault` method
+// JSDOM's implementation of requestSubmit triggers the submit event but then throws an error unless the submit handler returns false
 //
 // * Remove when JSDOM implements submit on its form elements *
 //
@@ -11,7 +11,9 @@
 //
 // form elements link to their implementation instance via a symbol property
 // this spies on the submit method of the implementation instance for a form element and mocks it to prevent 'not implemented' errors
-function spyOnFormSubmit (jest, form) {
+// it returns a spy on the event preventDefault function because submit is called every time, no matter if they submission will happen or not
+
+function spyOnFormSubmitEventPrevention (jest, form) {
 
   const formImplementationSymbols = Object.getOwnPropertySymbols(form).filter(
     symbol => form[symbol].constructor.name === 'HTMLFormElementImpl'
@@ -23,11 +25,15 @@ function spyOnFormSubmit (jest, form) {
 
   const HTMLFormElementImpl = form[formImplementationSymbols[0]];
 
-  const submitSpy = jest.spyOn(HTMLFormElementImpl, 'submit')
+  const event = new Event("submit", {bubbles: true, cancelable: true})
+  const preventDefaultSpy = jest.spyOn(event, 'preventDefault')
 
-  submitSpy.mockImplementation();
-  return submitSpy;
+  const submitSpy = jest.spyOn(HTMLFormElementImpl, 'requestSubmit')
+  submitSpy.mockImplementation(() => {
+    form.dispatchEvent(event)
+  });
 
+  return preventDefaultSpy;
 };
 
-exports.spyOnFormSubmit = spyOnFormSubmit;
+exports.spyOnFormSubmitEventPrevention = spyOnFormSubmitEventPrevention;

tests/javascripts/support/polyfills.js

@@ -1,53 +1,15 @@
 // Polyfills for any parts of the DOM API available in browsers but not JSDOM
 
-// From: https://gist.github.com/eligrey/1276030
-HTMLElement.prototype.insertAdjacentHTML = function(position, html) {
-  "use strict";
-
-  var
-      ref = this
-    , container = ref.ownerDocument.createElementNS("http://www.w3.org/1999/xhtml", "_")
-    , ref_parent = ref.parentNode
-    , node, first_child, next_sibling
-  ;
-
-  container.innerHTML = html;
-
-  switch (position.toLowerCase()) {
-    case "beforebegin":
-      while ((node = container.firstChild)) {
-        ref_parent.insertBefore(node, ref);
-      }
-      break;
-    case "afterbegin":
-      first_child = ref.firstChild;
-      while ((node = container.lastChild)) {
-        first_child = ref.insertBefore(node, first_child);
-      }
-      break;
-    case "beforeend":
-      while ((node = container.firstChild)) {
-        ref.appendChild(node);
-      }
-      break;
-    case "afterend":
-      next_sibling = ref.nextSibling;
-      while ((node = container.lastChild)) {
-        next_sibling = ref_parent.insertBefore(node, next_sibling);
-      }
-      break;
-  }
-
-};
-
-// from: https://developer.mozilla.org/en-US/docs/Web/API/Element/insertAdjacentText#Polyfill
-if (!Element.prototype.insertAdjacentText) {
-  Element.prototype.insertAdjacentText = function(type, txt){
-    this.insertAdjacentHTML(
-      type,
-      (txt+'') // convert to string
-        .replace(/&/g, '&') // embed ampersand symbols
-        .replace(/</g, '&lt;') // embed less-than symbols
-    )
-  }
+let _location = {
+  reload: jest.fn(),
+  hostname: "www.notifications.service.gov.uk",
+  assign: jest.fn(),
+  href: "https://www.notifications.service.gov.uk",
 }
+
+Object.defineProperty(window, 'location', {
+  get: () => _location,
+  set: (value) => {
+    _location = value
+  },
+})