Poll history - read only list of polls in current timeline (#10055)

* add settings while under development

* very basic tests for roomsummarycard

* empty poll history dialog and option in room summary

* pollS history in settings

* render an ugly list of polls in current timeline

* readonly poll history list items

* fix scroll window

* use short year code in date format, tidy

* no results message + tests

* strict fix

* mock intldatetimeformat for stable date formatting

* extract date format fn into date-utils

* jsdoc

test/components/views/dialogs/polls/PollListItem-test.tsx

@@ -0,0 +1,53 @@
+/*
+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.
+*/
+
+import React from "react";
+import { render } from "@testing-library/react";
+import { MatrixEvent } from "matrix-js-sdk/src/matrix";
+
+import PollListItem from "../../../../../src/components/views/dialogs/polls/PollListItem";
+import { makePollStartEvent, mockIntlDateTimeFormat, unmockIntlDateTimeFormat } from "../../../../test-utils";
+
+describe("<PollListItem />", () => {
+    const event = makePollStartEvent("Question?", "@me:domain.org");
+    event.getContent().origin;
+    const defaultProps = { event };
+    const getComponent = (props = {}) => render(<PollListItem {...defaultProps} {...props} />);
+
+    beforeAll(() => {
+        // mock default locale to en-GB and set timezone
+        // so these tests run the same everywhere
+        mockIntlDateTimeFormat();
+    });
+
+    afterAll(() => {
+        unmockIntlDateTimeFormat();
+    });
+
+    it("renders a poll", () => {
+        const { container } = getComponent();
+        expect(container).toMatchSnapshot();
+    });
+
+    it("renders null when event does not have an extensible poll start event", () => {
+        const event = new MatrixEvent({
+            type: "m.room.message",
+            content: {},
+        });
+        const { container } = getComponent({ event });
+        expect(container.firstElementChild).toBeFalsy();
+    });
+});