test: add testRender()

This adds a testRender() helper function to simplify UI tests. Instead
of mocking the redux store, we use the real thing.

src/about/AboutDialog.test.tsx

@@ -1,59 +1,29 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2021 The Pybricks Authors
+// Copyright (c) 2021-2022 The Pybricks Authors
 
-import { I18nContext, I18nManager } from '@shopify/react-i18n';
-import {
-    getByLabelText,
-    render,
-    screen,
-    waitForElementToBeRemoved,
-} from '@testing-library/react';
+import { getByLabelText, waitForElementToBeRemoved } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import React from 'react';
-import { Provider } from 'react-redux';
-import { Store } from 'redux';
+import { testRender } from '../../test';
 import AboutDialog from './AboutDialog';
 
 it('should close when the button is clicked', () => {
-    const store = {
-        getState: jest.fn(() => ({ licenses: { list: null } })),
-        dispatch: jest.fn(),
-        subscribe: jest.fn(),
-    } as unknown as Store;
-    const i18n = new I18nManager({ locale: 'en' });
     const close = jest.fn();
-    render(
-        <Provider store={store}>
-            <I18nContext.Provider value={i18n}>
-                <AboutDialog isOpen={true} onClose={() => close()} />
-            </I18nContext.Provider>
-        </Provider>,
-    );
 
-    userEvent.click(screen.getByLabelText('Close'));
+    const dialog = testRender(<AboutDialog isOpen={true} onClose={() => close()} />);
+
+    userEvent.click(dialog.getByLabelText('Close'));
 
     expect(close).toHaveBeenCalled();
 });
 
 it('should manage license dialog open/close', async () => {
-    const store = {
-        getState: jest.fn(() => ({ licenses: { list: null } })),
-        dispatch: jest.fn(),
-        subscribe: jest.fn(),
-    } as unknown as Store;
-    const i18n = new I18nManager({ locale: 'en' });
-    render(
-        <Provider store={store}>
-            <I18nContext.Provider value={i18n}>
-                <AboutDialog isOpen={true} onClose={() => undefined} />
-            </I18nContext.Provider>
-        </Provider>,
-    );
+    const dialog = testRender(<AboutDialog isOpen={true} onClose={() => undefined} />);
 
-    userEvent.click(screen.getByText('Software Licenses'));
+    userEvent.click(dialog.getByText('Software Licenses'));
 
     expect(
-        screen.getByText(
+        dialog.getByText(
             `${process.env.REACT_APP_NAME} is built on open source software.`,
             {
                 exact: false,
@@ -67,7 +37,7 @@ it('should manage license dialog open/close', async () => {
     userEvent.click(getByLabelText(licenseDialog, 'Close'));
 
     await waitForElementToBeRemoved(() =>
-        screen.queryByText(
+        dialog.queryByText(
             `${process.env.REACT_APP_NAME} is built on open source software.`,
             {
                 exact: false,