Improve code coverage

src/app/App.test.tsx

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+import { I18nContext, I18nManager } from '@shopify/react-i18n';
+import { render } from '@testing-library/react';
+import { mock } from 'jest-mock-extended';
+import React from 'react';
+import { Provider } from 'react-redux';
+import { Store } from 'redux';
+import { RootState } from '../reducers';
+import App from './App';
+
+it.each([false, true])('should render', (darkMode) => {
+    const store = mock<Store<RootState>>({
+        getState: () => mock<RootState>({ settings: { darkMode } }),
+    });
+
+    const i18n = new I18nManager({ locale: 'en' });
+
+    render(
+        <Provider store={store}>
+            <I18nContext.Provider value={i18n}>
+                <App />
+            </I18nContext.Provider>
+        </Provider>,
+    );
+});

src/ble-device-info-service/protocol.test.ts

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+import {
+    HubType,
+    LegoCompanyId,
+    TechnicLargeHubVariant,
+} from '../ble-lwp3-service/protocol';
+import { decodePnpId, getHubTypeName } from './protocol';
+
+function encodeInfo(id: HubType, variant?: number) {
+    return new DataView(
+        new Uint8Array([
+            1, // Bluetooth SIG
+            LegoCompanyId & 0xff,
+            LegoCompanyId >> 8,
+            id,
+            0,
+            variant ?? 0,
+            0,
+        ]).buffer,
+    );
+}
+
+test.each([
+    [encodeInfo(HubType.MoveHub), 'Move hub'],
+    [encodeInfo(HubType.CityHub), 'City hub'],
+    [encodeInfo(HubType.TechnicHub), 'Technic hub'],
+    [
+        encodeInfo(HubType.TechnicLargeHub, TechnicLargeHubVariant.SpikePrimeHub),
+        'Prime hub',
+    ],
+    [
+        encodeInfo(
+            HubType.TechnicLargeHub,
+            TechnicLargeHubVariant.MindstormsInventorHub,
+        ),
+        'Inventor hub',
+    ],
+    [encodeInfo(HubType.TechnicSmallHub), 'Essential hub'],
+])('should correctly decode data', (data, expected) => {
+    expect(getHubTypeName(decodePnpId(data))).toBe(expected);
+});

src/status-bar/StatusBar.test.tsx

@@ -1,11 +1,15 @@
 // SPDX-License-Identifier: MIT
 // Copyright (c) 2021 The Pybricks Authors
 
-import { fireEvent, render, screen } from '@testing-library/react';
+import { I18nContext, I18nManager } from '@shopify/react-i18n';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { mock } from 'jest-mock-extended';
 import React from 'react';
 import { Provider } from 'react-redux';
 import { Store } from 'redux';
 import { BleConnectionState } from '../ble/reducers';
+import { RootState } from '../reducers';
 import StatusBar from './StatusBar';
 
 it('should prevent browser context menu', () => {
@@ -24,3 +28,67 @@ it('should prevent browser context menu', () => {
 
     expect(fireEvent.contextMenu(screen.getByRole('status'))).toBe(false);
 });
+
+it('should show popover when hub name is clicked', async () => {
+    const testHubName = 'Test hub';
+
+    const store = mock<Store<RootState>>({
+        getState: () =>
+            mock<RootState>({
+                ble: {
+                    connection: BleConnectionState.Connected,
+                    deviceName: testHubName,
+                    deviceType: 'hub type',
+                    deviceFirmwareVersion: 'v0.0.0',
+                    deviceLowBatteryWarning: false,
+                    deviceBatteryCharging: false,
+                },
+            }),
+    });
+
+    const i18n = new I18nManager({ locale: 'en' });
+
+    render(
+        <Provider store={store}>
+            <I18nContext.Provider value={i18n}>
+                <StatusBar />
+            </I18nContext.Provider>
+        </Provider>,
+    );
+
+    userEvent.click(screen.getByText(testHubName));
+
+    await waitFor(() => screen.getByText('Connected to:'));
+});
+
+it('should show popover when battery is clicked', async () => {
+    const testHubName = 'Test hub';
+
+    const store = mock<Store<RootState>>({
+        getState: () =>
+            mock<RootState>({
+                ble: {
+                    connection: BleConnectionState.Connected,
+                    deviceName: testHubName,
+                    deviceType: 'hub type',
+                    deviceFirmwareVersion: 'v0.0.0',
+                    deviceLowBatteryWarning: false,
+                    deviceBatteryCharging: false,
+                },
+            }),
+    });
+
+    const i18n = new I18nManager({ locale: 'en' });
+
+    render(
+        <Provider store={store}>
+            <I18nContext.Provider value={i18n}>
+                <StatusBar />
+            </I18nContext.Provider>
+        </Provider>,
+    );
+
+    userEvent.click(screen.getByTitle('Battery'));
+
+    await waitFor(() => screen.getByText('Battery level is OK.'));
+});

src/terminal/Terminal.tsx

@@ -106,6 +106,7 @@ const Terminal: React.FC = (_props) => {
 
     // xterm.open() has to be called after terminalRef has been rendered
     useEffect(() => {
+        // istanbul ignore if: should not happen ever
         if (!terminalRef.current) {
             console.error('Missing terminal reference');
             return;

src/utils/ViewHeightSensor.test.tsx

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+import { render } from '@testing-library/react';
+import React from 'react';
+import ViewHeightSensor from './ViewHeightSensor';
+
+it('should set the --pb-vh variable on resize', () => {
+    render(<ViewHeightSensor />);
+    // REVISIT: it is not easy to test the resize event since jest-dom doesn't do layout
+});

src/utils/monkey-patch.ts

@@ -26,6 +26,7 @@ export function useTooltip2MonkeyPatch<T>(): React.RefObject<Tooltip2<T>> {
     const tooltipRef = useRef<Tooltip2<T>>(null);
 
     useEffect(() => {
+        // istanbul ignore if: should not happen ever
         if (!tooltipRef.current) {
             return;
         }
@@ -55,6 +56,7 @@ export function useTooltip2MonkeyPatch<T>(): React.RefObject<Tooltip2<T>> {
  * @param tooltipRef The reference returned from useTooltip2MonkeyPatch()
  */
 export function closeTooltip2<T>(tooltipRef: React.RefObject<Tooltip2<T>>): void {
+    // istanbul ignore if: should not happen ever
     if (!tooltipRef.current) {
         return;
     }