feat: add notification about available new version

cli/index.ts

@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 /* tslint:disable:no-implicit-dependencies */
 import * as React from 'react';
+import * as updateNotifier from 'update-notifier';
 import { renderToString } from 'react-dom/server';
 import { ServerStyleSheet } from 'styled-components';
 
@@ -111,6 +112,7 @@ const handlerForBuildCommand = async (argv: any) => {
   };
 
   try {
+    notifyUpdateCliVersion();
     await bundle(argv.spec, config);
   } catch (e) {
     handleError(e);
@@ -174,6 +176,7 @@ YargsParser.command(
     };
 
     try {
+      notifyUpdateCliVersion();
       await serve(argv.host as string, argv.port as number, argv.spec as string, config);
     } catch (e) {
       handleError(e);
@@ -468,3 +471,13 @@ function getObjectOrJSON(options) {
       return {};
   }
 }
+
+function notifyUpdateCliVersion() {
+  const pkg = require('./package.json');
+  const notifier = updateNotifier({
+    pkg,
+    updateCheckInterval: 0,
+    shouldNotifyInNpmScript: true,
+  });
+  notifier.notify();
+}

cli/package.json

@@ -21,6 +21,7 @@
     "react-dom": "^17.0.1",
     "redoc": "2.0.0-rc.72",
     "styled-components": "^5.3.0",
+    "update-notifier": "^5.0.1",
     "yargs": "^17.3.1"
   },
   "publishConfig": {