Repository: nodejs/node
Pull request: debugger: fix event listener leak in the run command

It should remove both the error and the ready event listeners attached when either of them fires, instead of removing only the one whose corresponding event fires, otherwise the other event listener will always get leaked.

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Changed files:
filename: lib/internal/debugger/inspect_client.js
patch: @@ -13,7 +13,7 @@ const {
 const Buffer = require('buffer').Buffer;
 const crypto = require('crypto');
 const { ERR_DEBUGGER_ERROR } = require('internal/errors').codes;
-const { EventEmitter } = require('events');
+const { EventEmitter, once } = require('events');
 const http = require('http');
 const { URL } = require('internal/url');
 
@@ -343,13 +343,10 @@ class Client extends EventEmitter {
       this.emit('ready');
     };
 
-    return new Promise((resolve, reject) => {
-      this.once('error', reject);
-      this.once('ready', resolve);
-
-      httpReq.on('upgrade', handshakeListener);
-      httpReq.end();
-    });
+    const onReady = once(this, 'ready');
+    httpReq.on('upgrade', handshakeListener);
+    httpReq.end();
+    return onReady;
   }
 }
 

filename: test/common/debugger.js
patch: @@ -141,6 +141,10 @@ function startCLI(args, flags = [], spawnOpts = {}, opts = { randomPort: true })
       return getOutput();
     },
 
+    get stderrOutput() {
+      return stderrOutput;
+    },
+
     get rawOutput() {
       return outputBuffer.join('').toString();
     },

filename: test/parallel/test-debugger-restart-message.js
patch: @@ -31,6 +31,8 @@ const startCLI = require('../common/debugger');
     } finally {
       await cli.quit();
     }
+
+    assert.doesNotMatch(cli.stderrOutput, /MaxListenersExceededWarning/);
   }
 
   onWaitForInitialBreak();