Hide app selector if no devices are available

Summary:
As reported in https://fb.workplace.com/groups/748354712423318/permalink/773382183253904/, special case no devices being present and suggest to launch an emulator.

Also extends `useStore()` hook to accept no arguments, in which case it works as Redux's own `useStore` hook, except that it is strongly typed.

Reviewed By: passy

Differential Revision: D25803497

fbshipit-source-id: d448ac41e0ba7b713ee883caeb27736a2901975c

desktop/app/src/sandy-chrome/LeftRail.tsx

@@ -47,7 +47,6 @@ import {logout, USER_NOT_SIGNEDIN, USER_UNAUTHORIZED} from '../reducers/user';
 import config from '../fb-stubs/config';
 import styled from '@emotion/styled';
 import {showEmulatorLauncher} from './appinspect/LaunchEmulator';
-import {useStore as useReduxStore} from 'react-redux';
 import SupportRequestFormV2 from '../fb-stubs/SupportRequestFormV2';
 import {setStaticView} from '../reducers/connections';
 import {getInstance} from '../fb-stubs/Logger';
@@ -252,7 +251,7 @@ function DebugLogsButton({
 }
 
 function LaunchEmulatorButton() {
-  const store = useReduxStore();
+  const store = useStore();
 
   return (
     <LeftRailButton

desktop/app/src/sandy-chrome/appinspect/AppSelector.tsx

@@ -8,12 +8,13 @@
  */
 
 import React from 'react';
-import {Button, Dropdown, Menu, Radio, Typography} from 'antd';
+import {Alert, Button, Dropdown, Menu, Radio, Typography} from 'antd';
 import {
   AppleOutlined,
   AndroidOutlined,
   WindowsOutlined,
   CaretDownOutlined,
+  RocketOutlined,
 } from '@ant-design/icons';
 import {Glyph, Layout, styled} from '../../ui';
 import {theme, useTrackedCallback} from 'flipper-plugin';
@@ -30,8 +31,9 @@ import {getColorByApp} from '../../chrome/mainsidebar/sidebarUtils';
 import Client from '../../Client';
 import {State} from '../../reducers';
 import {brandIcons} from '../../ui/components/colors';
+import {showEmulatorLauncher} from './LaunchEmulator';
 
-const {Text} = Typography;
+const {Text, Link, Title} = Typography;
 
 function getOsIcon(os?: OS) {
   switch (os) {
@@ -86,7 +88,7 @@ export function AppSelector() {
   );
   const client = clients.find((client) => client.id === selectedApp);
 
-  return (
+  return entries.length ? (
     <Radio.Group
       value={selectedApp}
       size="small"
@@ -96,9 +98,7 @@ export function AppSelector() {
       }}>
       <Dropdown
         overlay={
-          <Menu selectedKeys={selectedApp ? [selectedApp] : []}>
-            {entries.flat()}
-          </Menu>
+          <Menu selectedKeys={selectedApp ? [selectedApp] : []}>{entries}</Menu>
         }>
         <AppInspectButton title="Select the device / app to inspect">
           <Layout.Horizontal gap center>
@@ -114,6 +114,8 @@ export function AppSelector() {
         </AppInspectButton>
       </Dropdown>
     </Radio.Group>
+  ) : (
+    <NoDevices />
   );
 }
 
@@ -216,5 +218,36 @@ function computeEntries(
       )),
     ]);
   }
-  return entries;
+  return entries.flat();
+}
+
+function NoDevices() {
+  const store = useStore();
+
+  const onLaunchEmulator = useTrackedCallback(
+    'select-emulator',
+    () => {
+      showEmulatorLauncher(store);
+    },
+    [],
+  );
+
+  return (
+    <Alert
+      type="info"
+      message={
+        <>
+          <Title level={4}>No devices found</Title>
+          <Text>
+            Start a fresh emulator <RocketOutlined onClick={onLaunchEmulator} />{' '}
+            or check the{' '}
+            <Link href="https://fbflipper.com/docs/troubleshooting">
+              troubleshooting guide
+            </Link>
+            .
+          </Text>
+        </>
+      }
+    />
+  );
 }

desktop/app/src/utils/useStore.tsx

@@ -8,12 +8,13 @@
  */
 
 import {
+  useStore as useReduxStore,
   useSelector,
   shallowEqual,
   useDispatch as useDispatchBase,
 } from 'react-redux';
 import {Dispatch as ReduxDispatch} from 'redux';
-import {State, Actions} from '../reducers/index';
+import {State, Actions, Store} from '../reducers/index';
 
 /**
  * Strongly typed wrapper or Redux's useSelector.
@@ -22,9 +23,14 @@ import {State, Actions} from '../reducers/index';
  */
 export function useStore<Selected>(
   selector: (state: State) => Selected,
-  equalityFn: (left: Selected, right: Selected) => boolean = shallowEqual,
-): Selected {
-  return useSelector(selector, equalityFn);
+  equalityFn?: (left: Selected, right: Selected) => boolean,
+): Selected;
+export function useStore(): Store;
+export function useStore(selector?: any, equalityFn?: any) {
+  // eslint-disable-next-line react-hooks/rules-of-hooks
+  if (arguments.length === 0) return useReduxStore();
+  // eslint-disable-next-line react-hooks/rules-of-hooks
+  return useSelector(selector, equalityFn ?? shallowEqual);
 }
 
 export type Dispatch = ReduxDispatch<Actions>;