add cypress test case for simple poll flow (#9073)

* add cypress test case for simple poll flow

* tidy comments

* actually correct comments

* add polls x thread test

* tweak comments

* pr improvements

cypress/support/composer.ts

@@ -0,0 +1,48 @@
+/*
+Copyright 2022 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 {
+            // Get the composer element
+            // selects main timeline composer by default
+            // set `isRightPanel` true to select right panel composer
+            getComposer(isRightPanel?: boolean): Chainable<JQuery>;
+            // Open the message composer kebab menu
+            openMessageComposerOptions(isRightPanel?: boolean): Chainable<JQuery>;
+        }
+    }
+}
+
+Cypress.Commands.add("getComposer", (isRightPanel?: boolean): Chainable<JQuery> => {
+    const panelClass = isRightPanel ? '.mx_RightPanel' : '.mx_RoomView_body';
+    return cy.get(`${panelClass} .mx_MessageComposer`);
+});
+
+Cypress.Commands.add("openMessageComposerOptions", (isRightPanel?: boolean): Chainable<JQuery> => {
+    cy.getComposer(isRightPanel).within(() => {
+        cy.get('[aria-label="More options"]').click();
+    });
+    return cy.get('.mx_MessageComposer_Menu');
+});
+
+// Needed to make this file a module
+export { };