Bug 1880162 - Split off portPromises from ProxyMessenger.ports, r=robwu

Differential Revision: https://phabricator.services.mozilla.com/D206231

toolkit/components/extensions/ExtensionParent.sys.mjs

@@ -245,8 +245,10 @@ let apiManager = new (class extends SchemaAPIManager {
 // to relevant child messengers.  Also handles Native messaging and GeckoView.
 /** @typedef {typeof ProxyMessenger} NativeMessenger */
 const ProxyMessenger = {
-  /** @type {Map<number, Partial<ParentPort>&Promise<ParentPort>>} */
+  /** @type {Map<number, ParentPort>} */
   ports: new Map(),
+  /** @type {Map<number, Promise>} */
+  portPromises: new Map(),
 
   init() {
     this.conduit = new lazy.BroadcastConduit(ProxyMessenger, {
@@ -363,17 +365,24 @@ const ProxyMessenger = {
     }
 
     // PortMessages that follow will need to wait for the port to be opened.
-    /** @type {callback} */
-    let resolvePort;
-    this.ports.set(arg.portId, new Promise(res => (resolvePort = res)));
+    let { promise, resolve, reject } = Promise.withResolvers();
+    this.portPromises.set(arg.portId, promise);
 
-    let kind = await this.normalizeArgs(arg, sender);
-    let all = await this.conduit.castPortConnect(kind, arg);
-    resolvePort();
+    try {
+      let kind = await this.normalizeArgs(arg, sender);
+      let all = await this.conduit.castPortConnect(kind, arg);
+      resolve();
 
-    // If there are no active onConnect listeners.
-    if (!all.some(x => x.value)) {
-      throw new ExtensionError(ERROR_NO_RECEIVERS);
+      // If there are no active onConnect listeners.
+      if (!all.some(x => x.value)) {
+        throw new ExtensionError(ERROR_NO_RECEIVERS);
+      }
+    } catch (err) {
+      // Throw _and_ reject with error, so everything awaiting this port fails.
+      reject(err);
+      throw err;
+    } finally {
+      this.portPromises.delete(arg.portId);
     }
   },
 
@@ -387,7 +396,7 @@ const ProxyMessenger = {
     // NOTE: the following await make sure we await for promised ports
     // (ports that were not yet open when added to the Map,
     // see recvPortConnect).
-    await this.ports.get(sender.portId);
+    await this.portPromises.get(sender.portId);
     this.sendPortMessage(sender.portId, holder, !sender.source);
   },