From 0ac506be85f91fc156929e2fbd73404926bba22c Mon Sep 17 00:00:00 2001
From: Florian Klampfer <mail@qwtel.com>
Date: Sat, 31 Aug 2024 13:04:42 +0700
Subject: [PATCH] Commit

---
 src/caplink.ts      | 21 +++++++++++----------
 src/node-adapter.ts | 42 +++++++++++++++++-------------------------
 src/protocol.ts     |  3 ++-
 3 files changed, 30 insertions(+), 36 deletions(-)

diff --git a/src/caplink.ts b/src/caplink.ts
index 19177a4..3a94be7 100644
--- a/src/caplink.ts
+++ b/src/caplink.ts
@@ -465,9 +465,12 @@ export function wrap<T>(ep: Endpoint, target?: any): Remote<T> {
   return createProxy<T>(ep, [], target) as any;
 }
 
-function throwIfProxyReleased(isReleased: boolean) {
+function throwIfProxyReleased(isReleased: boolean|string|Error) {
   if (isReleased) {
-    throw new Error("Proxy has been released and is not useable");
+    throw new Error(
+      "Proxy has been released and is not useable" + (typeof isReleased === 'string' ? `: ${isReleased}` : ''),
+      isReleased instanceof Error ? { cause: isReleased } : {},
+    );
   }
 }
 
@@ -475,9 +478,7 @@ async function releaseEndpoint(ep: Endpoint, force = false) {
   if (endpointState.has(ep)) {
     const { resolvers, messageHandler } = endpointState.get(ep)!;
     try {
-      const releasedPromise = !force ? requestResponseMessage(ep, {
-        type: MessageType.RELEASE,
-      }) : null;
+      const releasedPromise = !force && requestResponseMessage(ep, { type: MessageType.RELEASE });
       endpointState.delete(ep); // prevent reentry
       await releasedPromise; // now save to await
     } finally {
@@ -518,7 +519,7 @@ function createProxy<T>(
   path: PropertyKey[] = [],
   target: object = function () {}
 ): Remote<T> {
-  let isProxyReleased = false;
+  let isProxyReleased: boolean|string|Error = false;
   const proxy = new Proxy(target, {
     get(_target, prop) {
       if (prop === Symbol.dispose || prop === releaseProxy) {
@@ -632,16 +633,16 @@ function createProxy<T>(
   // If the endpoint gets closed on us, we should mark the proxy as released and reject all pending promises.
   // This shouldn't really happen since the proxy must be closed from this side, either through manual dispose or finalization registry.
   // Also note that support for the `close` event is unclear (MDN doesn't document it, spec says it should be there...), so this is a last resort.
-  ep.addEventListener("close", async () => {
-    isProxyReleased = true;
+  ep.addEventListener("close", async (ev) => {
+    isProxyReleased = ev.reason ?? 'closed';
     unregisterProxy(proxy);
     // Passing the force flag to skip sending a release message, since the endpoint is already closed.
     await releaseEndpoint(ep, true);
   });
 
   // Similarly, if the endpoint errors for any reason, we should mark the proxy as released and reject all pending promises.
-  ep.addEventListener("error", async () => {
-    isProxyReleased = true;
+  ep.addEventListener("error", async (ev) => {
+    isProxyReleased = ev.error instanceof Error ? ev.error : 'errored';
     unregisterProxy(proxy);
     await releaseEndpoint(ep, true);
   });
diff --git a/src/node-adapter.ts b/src/node-adapter.ts
index 5f6ca58..24724a9 100644
--- a/src/node-adapter.ts
+++ b/src/node-adapter.ts
@@ -21,43 +21,35 @@ import type { Endpoint } from "./protocol.ts";
 
 export interface NodeEndpoint {
   postMessage(message: any, transfer?: any[]): void;
-  on(
-    type: string,
-    listener: EventListenerOrEventListenerObject,
-    options?: {}
-  ): void;
-  off(
-    type: string,
-    listener: EventListenerOrEventListenerObject,
-    options?: {}
-  ): void;
+  on(type: string, listener: (value: any) => void): void;
+  off(type: string, listener: (value: any) => void): void;
   start?: () => void;
 }
 
+const mkl = (eh: EventListenerOrEventListenerObject) => (data: any) => {
+  if ("handleEvent" in eh) {
+    eh.handleEvent({ data } as MessageEvent); // XXX: doesn't work for non-MessageEvent
+  } else {
+    eh({ data } as MessageEvent); // XXX: doesn't work for non-MessageEvent
+  }
+};
+
 export default function nodeEndpoint(nep: Endpoint|NodeEndpoint): Endpoint {
   if (!('on' in nep) || !('off' in nep)) return nep;
   const listeners = new WeakMap();
   return {
     postMessage: nep.postMessage.bind(nep),
-    addEventListener: (_: string, eh: any) => {
-      const l = (data: any) => {
-        if ("handleEvent" in eh) {
-          eh.handleEvent({ data } as MessageEvent);
-        } else {
-          eh({ data } as MessageEvent);
-        }
-      };
-      nep.on("message", l);
+    addEventListener: (name: string, eh: EventListenerOrEventListenerObject) => {
+      const l = mkl(eh);
+      nep.on(name, l);
       listeners.set(eh, l);
     },
-    removeEventListener: (_: string, eh: any) => {
+    removeEventListener: (name: string, eh: EventListenerOrEventListenerObject) => {
       const l = listeners.get(eh);
-      if (!l) {
-        return;
-      }
-      nep.off("message", l);
+      if (!l) return;
+      nep.off(name, l);
       listeners.delete(eh);
     },
-    start: nep.start && nep.start.bind(nep),
+    ...nep.start && { start: nep.start.bind(nep) },
   };
 }
diff --git a/src/protocol.ts b/src/protocol.ts
index 0d170bf..fab1e96 100644
--- a/src/protocol.ts
+++ b/src/protocol.ts
@@ -6,7 +6,8 @@
 
 import type { TypedEventTarget } from "@workers/typed-event-target";
 
-export type MessageEventTarget = Pick<TypedEventTarget<MessagePortEventMap>, "addEventListener"|"removeEventListener">;
+export type MessageEventTargetEventMap = MessagePortEventMap & { error: ErrorEvent, close: CloseEvent };
+export type MessageEventTarget = Pick<TypedEventTarget<MessageEventTargetEventMap>, "addEventListener"|"removeEventListener">;
 
 export const messageChannel = Symbol('Caplink.messageChannel');
 export const adoptNative = Symbol('Caplink.adaptNative');