Add support for disposing communicator with "await using" (#3526)

js/gulpfile.js

@@ -285,6 +285,12 @@ for (const name of tests) {
         let bundle = await rollup({
             input: input,
             plugins: [IceResolver(), NodeMockupResolver()],
+            onwarn: (warning, next) => {
+                // Ignore the "this is undefined" warning, let rollup silently rewrite it.
+                // This avoids warnings from the TypeScript polyfills for async disposable resources.
+                if (warning.code === "THIS_IS_UNDEFINED") return;
+                next(warning);
+            },
         });
         await bundle.write({
             file: path.join("dist", name, "index.js"),

js/src/Ice/Communicator.d.ts

@@ -22,6 +22,11 @@ declare module "ice" {
              */
             destroy(): Promise<void>;
 
+            /**
+             * Asynchronously disposes this communicator. It's an alias for {@link Communicator#destroy}.
+             */
+            [Symbol.asyncDispose](): Promise<void>;
+
             /**
              * Shuts down this communicator. In JavaScript, shutdown resolves a promise and doesn't do anything else.
              *

js/src/Ice/Communicator.js

@@ -21,6 +21,10 @@ export class Communicator {
         return this._instance.destroy();
     }
 
+    [Symbol.asyncDispose]() {
+        return this.destroy();
+    }
+
     shutdown() {
         if (!this._isShutdown) {
             this._isShutdown = true;

js/test/Ice/properties/Client.ts

@@ -118,7 +118,7 @@ export class Client extends TestHelper {
         }
 
         {
-            const communicator = Ice.initialize(args);
+            await using communicator = Ice.initialize(args);
             const properties = communicator.getProperties();
 
             out.write("testing that creating an object adapter with unknown properties throws an exception...");