add retry mechanism before terminating an unresponsive debugger socket

Differential Revision: D58220230

packages/dev-middleware/src/inspector-proxy/InspectorProxy.js

@@ -23,6 +23,8 @@ import type {IncomingMessage, ServerResponse} from 'http';
 import type {Timeout} from 'timers';
 
 import Device from './Device';
+import {logger} from '@react-native-community/cli-tools';
+import chalk from 'chalk';
 import nullthrows from 'nullthrows';
 // Import these from node:timers to get the correct Flow types.
 // $FlowFixMe[cannot-resolve-module] libdef missing in RN OSS
@@ -38,6 +40,7 @@ const PAGES_LIST_JSON_URL = '/json';
 const PAGES_LIST_JSON_URL_2 = '/json/list';
 const PAGES_LIST_JSON_VERSION_URL = '/json/version';
 const MAX_PONG_LATENCY_MS = 5000;
+const MAX_MISSED_PONG_COUNT = 3;
 const DEBUGGER_HEARTBEAT_INTERVAL_MS = 10000;
 
 const INTERNAL_ERROR_CODE = 1011;
@@ -297,6 +300,7 @@ export default class InspectorProxy implements InspectorProxyQueries {
   // https://datatracker.ietf.org/doc/html/rfc6455#section-5.5.2
   #startHeartbeat(socket: WS, intervalMs: number) {
     let terminateTimeout = null;
+    let missedPongCount = 0;
 
     const pingTimeout: Timeout = setTimeout(() => {
       if (socket.readyState !== WS.OPEN) {
@@ -309,6 +313,16 @@ export default class InspectorProxy implements InspectorProxyQueries {
         if (socket.readyState !== WS.OPEN) {
           return;
         }
+        if (missedPongCount < MAX_MISSED_PONG_COUNT) {
+          missedPongCount++;
+
+          logger.warn(
+            `Temporarily lost connection to the debugger. Reconnecting in ${intervalMs / 1000} seconds (attempt ${missedPongCount} of ${MAX_MISSED_PONG_COUNT})…`,
+          );
+          pingTimeout.refresh();
+          return;
+        }
+
         // We don't use close() here because that initiates a closing handshake,
         // which will not complete if the other end has gone away - 'close'
         // would not be emitted.
@@ -320,11 +334,24 @@ export default class InspectorProxy implements InspectorProxyQueries {
     }, intervalMs).unref();
 
     socket.on('pong', () => {
+      if (missedPongCount > 0) {
+        logger.info('Connection to the debugger restored.');
+        missedPongCount = 0;
+      }
       terminateTimeout && clearTimeout(terminateTimeout);
       pingTimeout.refresh();
     });
 
     socket.on('close', () => {
+      if (missedPongCount > 0) {
+        logger.error(
+          `Couldn't reconnect to the debugger after ${missedPongCount} attempt${missedPongCount > 1 ? 's' : ''}.`,
+        );
+        missedPongCount = 0;
+      }
+      logger.info(
+        `The debugger has disconnected. You may restart the debugger by typing ${chalk.bold('j')} in the terminal.`,
+      );
       terminateTimeout && clearTimeout(terminateTimeout);
       clearTimeout(pingTimeout);
     });