Extract getAppVersion() util

Summary:
Just some simple memoisation so we limit this particular `remote`
call to one per session.

Reviewed By: mweststrate

Differential Revision: D26223274

fbshipit-source-id: 7a12764758823c52f68fb7075f46caf58affb22f

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

@@ -22,7 +22,8 @@ const {Text, Title} = Typography;
 
 import constants from '../fb-stubs/constants';
 import isProduction from '../utils/isProduction';
-import {shell, remote} from 'electron';
+import {getAppVersion} from '../utils/info';
+import {shell} from 'electron';
 
 const RowContainer = styled(FlexRow)({
   alignItems: 'flex-start',
@@ -144,9 +145,7 @@ function WelcomeScreenContent() {
         <Image width={125} height={125} src="./icon.png" preview={false} />
         <Title level={1}>Welcome to Flipper</Title>
         <Text style={{color: theme.textColorPlaceholder}}>
-          {isProduction() && remote
+          {isProduction() ? `Version ${getAppVersion()}` : 'Development Mode'}
-            ? `Version ${remote.app.getVersion()}`
-            : 'Development Mode'}
         </Text>
       </Space>
       <Space direction="vertical" size="large" style={{width: '100%'}}>

desktop/app/src/utils/exportData.tsx

@@ -17,6 +17,7 @@ import {State as PluginStatesState} from '../reducers/pluginStates';
 import {State as PluginsState} from '../reducers/plugins';
 import {PluginNotification} from '../reducers/notifications';
 import Client, {ClientExport, ClientQuery} from '../Client';
+import {getAppVersion} from './info';
 import {pluginKey} from '../reducers/pluginStates';
 import {
   callClient,
@@ -383,7 +384,7 @@ async function addSaltToDeviceSerial({
   });
   const revision: string | undefined = await readCurrentRevision();
   return {
-    fileVersion: remote.app.getVersion(),
+    fileVersion: getAppVersion() || 'unknown',
     flipperReleaseRevision: revision,
     clients: updatedClients,
     device: {...newDevice.toJSON(), pluginStates: devicePluginStates},

desktop/app/src/utils/info.tsx

@@ -8,6 +8,7 @@
  */
 
 import os from 'os';
+import {remote} from 'electron';
 
 export type Info = {
   arch: string;
@@ -35,6 +36,17 @@ export function getInfo(): Info {
   };
 }
 
+let APP_VERSION: string | undefined = undefined;
+// Prefer using this function over manually calling `remote.app.getVersion()`
+// as calls to the remote object go over IPC and can be slow.
+export function getAppVersion(): string | undefined {
+  if (APP_VERSION === undefined && remote) {
+    APP_VERSION = remote.app.getVersion();
+  }
+
+  return APP_VERSION;
+}
+
 export function stringifyInfo(info: Info): string {
   const lines = [
     `Platform: ${info.platform} ${info.arch}`,

desktop/app/src/utils/versionString.tsx

@@ -8,15 +8,13 @@
  */
 
 import isProduction from '../utils/isProduction';
-import {remote} from 'electron';
+import {getAppVersion} from './info';
 import config from '../fb-stubs/config';
 import ReleaseChannel from '../ReleaseChannel';
 
-const version = remote.app.getVersion();
-
 export function getVersionString() {
   return (
-    version +
+    getAppVersion() +
     (isProduction() ? '' : '-dev') +
     (config.getReleaseChannel() !== ReleaseChannel.STABLE
       ? `-${config.getReleaseChannel()}`