nits

.eslintrc.js

@@ -362,6 +362,6 @@ module.exports = {
     btoa: 'readable',
     atob: 'readable',
     performance: 'readable',
-    structuredClone: 'readable'
+    structuredClone: 'readable',
   },
 };

lib/internal/bootstrap/node.js

@@ -256,7 +256,7 @@ if (!config.noBrowserGlobals) {
   defineOperation(globalThis, 'setImmediate', timers.setImmediate);
 
   const {
-    structuredClone
+    structuredClone,
   } = require('internal/structured_clone');
   defineOperation(globalThis, 'structuredClone', structuredClone);
 }

lib/internal/structured_clone.js

@@ -2,16 +2,14 @@
 
 const {
   MessageChannel,
-  receiveMessageOnPort
+  receiveMessageOnPort,
 } = require('internal/worker/io');
 
 let channel;
 function structuredClone(value, transfer) {
   // TODO: Improve this with a more efficient solution that avoids
   // instantiating a MessageChannel
-  if (!channel) {
-    channel = new MessageChannel();
-  }
+  channel ??= new MessageChannel();
   channel.port1.unref();
   channel.port2.unref();
   channel.port1.postMessage(value, transfer);