deps,test: fix undici globals on frozen globalThis

deps/undici/src/lib/global.js

@@ -8,6 +8,9 @@ const { InvalidArgumentError } = require('./core/errors')
 const Agent = require('./dispatcher/agent')
 const Dispatcher1Wrapper = require('./dispatcher/dispatcher1-wrapper')
 
+// Fallback storage used when globalThis is not extensible (e.g. Object.freeze(globalThis)).
+let fallbackDispatcher
+
 if (getGlobalDispatcher() === undefined) {
   setGlobalDispatcher(new Agent())
 }
@@ -17,25 +20,31 @@ function setGlobalDispatcher (agent) {
     throw new InvalidArgumentError('Argument agent must implement Agent')
   }
 
-  Object.defineProperty(globalThis, globalDispatcher, {
-    value: agent,
-    writable: true,
-    enumerable: false,
-    configurable: false
-  })
-
-  const legacyAgent = agent instanceof Dispatcher1Wrapper ? agent : new Dispatcher1Wrapper(agent)
-
-  Object.defineProperty(globalThis, legacyGlobalDispatcher, {
-    value: legacyAgent,
-    writable: true,
-    enumerable: false,
-    configurable: false
-  })
+  try {
+    Object.defineProperty(globalThis, globalDispatcher, {
+      value: agent,
+      writable: true,
+      enumerable: false,
+      configurable: false
+    })
+
+    const legacyAgent = agent instanceof Dispatcher1Wrapper ? agent : new Dispatcher1Wrapper(agent)
+
+    Object.defineProperty(globalThis, legacyGlobalDispatcher, {
+      value: legacyAgent,
+      writable: true,
+      enumerable: false,
+      configurable: false
+    })
+  } catch {
+    // globalThis is not extensible (e.g. frozen via Object.freeze(globalThis)).
+    // Fall back to module-level storage so that fetch, WebSocket, etc. still work.
+    fallbackDispatcher = agent
+  }
 }
 
 function getGlobalDispatcher () {
-  return globalThis[globalDispatcher]
+  return globalThis[globalDispatcher] ?? fallbackDispatcher
 }
 
 // These are the globals that can be installed by undici.install().

deps/undici/undici.js

@@ -10470,30 +10470,35 @@ var require_global2 = __commonJS({
     var { InvalidArgumentError } = require_errors();
     var Agent = require_agent();
     var Dispatcher1Wrapper = require_dispatcher1_wrapper();
+    var fallbackDispatcher;
     if (getGlobalDispatcher2() === void 0) {
       setGlobalDispatcher2(new Agent());
     }
     function setGlobalDispatcher2(agent) {
       if (!agent || typeof agent.dispatch !== "function") {
         throw new InvalidArgumentError("Argument agent must implement Agent");
       }
-      Object.defineProperty(globalThis, globalDispatcher, {
-        value: agent,
-        writable: true,
-        enumerable: false,
-        configurable: false
-      });
-      const legacyAgent = agent instanceof Dispatcher1Wrapper ? agent : new Dispatcher1Wrapper(agent);
-      Object.defineProperty(globalThis, legacyGlobalDispatcher, {
-        value: legacyAgent,
-        writable: true,
-        enumerable: false,
-        configurable: false
-      });
+      try {
+        Object.defineProperty(globalThis, globalDispatcher, {
+          value: agent,
+          writable: true,
+          enumerable: false,
+          configurable: false
+        });
+        const legacyAgent = agent instanceof Dispatcher1Wrapper ? agent : new Dispatcher1Wrapper(agent);
+        Object.defineProperty(globalThis, legacyGlobalDispatcher, {
+          value: legacyAgent,
+          writable: true,
+          enumerable: false,
+          configurable: false
+        });
+      } catch {
+        fallbackDispatcher = agent;
+      }
     }
     __name(setGlobalDispatcher2, "setGlobalDispatcher");
     function getGlobalDispatcher2() {
-      return globalThis[globalDispatcher];
+      return globalThis[globalDispatcher] ?? fallbackDispatcher;
     }
     __name(getGlobalDispatcher2, "getGlobalDispatcher");
     var installedExports = (

test/parallel/test-undici-frozen-globalthis.js

@@ -0,0 +1,26 @@
+'use strict';
+
+// Test that globals provided by undici (fetch, WebSocket, etc.) do not throw
+// when globalThis has been frozen via Object.freeze(globalThis).
+//
+// Refs: https://github.com/nodejs/node/issues/46788
+
+require('../common');
+
+// Freeze globalThis before any undici globals are accessed.
+Object.freeze(globalThis);
+
+const assert = require('node:assert');
+
+// Accessing these globals triggers undici's lazy initialisation, which calls
+// setGlobalDispatcher internally. With a frozen globalThis, the original code
+// threw: "TypeError: Cannot define property Symbol(undici.globalDispatcher.2),
+// object is not extensible". The fix uses a module-level fallback instead.
+assert.strictEqual(typeof fetch, 'function', 'fetch must be a function');
+assert.strictEqual(typeof WebSocket, 'function', 'WebSocket must be a function');
+assert.strictEqual(typeof Response, 'function', 'Response must be a function');
+assert.strictEqual(typeof Request, 'function', 'Request must be a function');
+assert.strictEqual(typeof Headers, 'function', 'Headers must be a function');
+assert.strictEqual(typeof FormData, 'function', 'FormData must be a function');
+
+console.log('All undici globals accessible after Object.freeze(globalThis)');