use WeakRef and WeakMap

Author: arcticnotes

lib/node/node-wsh.js

@@ -22,7 +22,7 @@ export class WindowsScriptingHost extends EventEmitter {
 	#trace;
 	#finalizer = new FinalizationRegistry( this.#finalized.bind( this));
 	#ref2proxy = new Map();
-	#proxy2ref = new Map();
+	#proxy2ref = new WeakMap();
 
 	#objectHandler = {
 
@@ -137,21 +137,24 @@ export class WindowsScriptingHost extends EventEmitter {
 	}
 
 	#getOrCreate( ref, handler) {
-		const existingProxy = this.#ref2proxy.get( ref);
+		const existingWeakRef = this.#ref2proxy.get( ref);
+		const existingProxy = existingWeakRef && existingWeakRef.deref();
 		if( existingProxy)
 			return existingProxy;
 
 		const target = handler === this.#objectHandler? new RemoteObject( ref): function() {};
 		const newProxy = new Proxy( target, handler);
 		target[ PROXY] = newProxy;
-		this.#ref2proxy.set( ref, newProxy);
+		this.#ref2proxy.set( ref, new WeakRef( newProxy)); // may be overwriting a dead WeakRef
 		this.#proxy2ref.set( newProxy, ref);
 		this.#finalizer.register( newProxy, ref);
 		this.emit( 'ref', ref, newProxy);
 		return newProxy;
 	}
 
 	#finalized( ref) {
+		if( this.#ref2proxy.get( ref).deref() === undefined) // otherwise, it's overwritten by a refreshed proxy
+			this.#ref2proxy.delete( ref);
 		const output = this.#syncline.exchange( JSON.stringify( [ 'unref', ref]));
 		if( this.#trace >= TRACE_REF)
 			switch( output[ 0]) {
@@ -186,7 +189,7 @@ export class WindowsScriptingHost extends EventEmitter {
 				}
 				if( decoded instanceof RemoteObject) {
 					const objref = this.#proxy2ref.get( decoded);
-					if( objref === undefined)
+					if( objref === undefined) // not because garbage-collected, because clearly `decoded` is still alive
 						throw new Error( `remote object reference not found: ${ decoded}`);
 					return { type: 'objref', value: objref};
 				}
@@ -196,7 +199,7 @@ export class WindowsScriptingHost extends EventEmitter {
 				return encoded;
 			case 'function':
 				const funref = this.#proxy2ref.get( decoded);
-				if( funref === undefined)
+				if( funref === undefined) // not because garbage-collected, because clearly `decoded` is still alive
 					throw new Error( `functions from node are disallowed: ${ decoded}`);
 				return { type: 'funref', value: funref};
 			case 'bigint':