Add Cypress Testing Library (#10446)

cypress/support/e2e.ts

@@ -18,6 +18,7 @@ limitations under the License.
 
 import "@percy/cypress";
 import "cypress-real-events";
+import "@testing-library/cypress/add-commands";
 
 import "./homeserver";
 import "./login";
@@ -37,3 +38,4 @@ import "./network";
 import "./composer";
 import "./proxy";
 import "./axe";
+import "./find";

cypress/support/find.ts

@@ -0,0 +1,70 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/// <reference types="cypress" />
+
+import Chainable = Cypress.Chainable;
+
+declare global {
+    // eslint-disable-next-line @typescript-eslint/no-namespace
+    namespace Cypress {
+        interface Chainable {
+            /**
+             * Finds an element with the role "button".
+             *
+             * @param name - accessible name of the element to find
+             */
+            findButton(name: string): Chainable<JQuery>;
+            /**
+             * Finds an element with the role "textbox".
+             *
+             * @param name - accessible name of the element to find
+             */
+            findTextbox(name: string): Chainable<JQuery>;
+            /**
+             * Finds an element with the role "option".
+             *
+             * @param name - accessible name of the element to find
+             */
+            findOption(name: string): Chainable<JQuery>;
+            /**
+             * Finds an element with the role "menuitem".
+             *
+             * @param name - accessible name of the element to find
+             */
+            findMenuitem(name: string): Chainable<JQuery>;
+        }
+    }
+}
+
+Cypress.Commands.add("findButton", (name: string): Chainable<JQuery> => {
+    return cy.findByRole("button", { name });
+});
+
+Cypress.Commands.add("findTextbox", (name: string): Chainable<JQuery> => {
+    return cy.findByRole("textbox", { name });
+});
+
+Cypress.Commands.add("findOption", (name: string): Chainable<JQuery> => {
+    return cy.findByRole("option", { name });
+});
+
+Cypress.Commands.add("findMenuitem", (name: string): Chainable<JQuery> => {
+    return cy.findByRole("menuitem", { name });
+});
+
+// Needed to make this file a module
+export {};