Bug 1655442 - Make usage of nsIWorkerDebugger.addListener more explicit. r=loganfsmyth

Declare separate listener objects instead of relying on the presence of the
listener method in a broader class.

Differential Revision: https://phabricator.services.mozilla.com/D84964

devtools/server/actors/targets/worker.js

@@ -40,6 +40,11 @@ const WorkerTargetActor = protocol.ActorClassWithSpec(workerTargetSpec, {
     this._attached = false;
     this._threadActor = null;
     this._transport = null;
+
+    this._dbgListener = {
+      onClose: this._onWorkerClose.bind(this),
+      onError: this._onWorkerError.bind(this),
+    };
   },
 
   form() {
@@ -83,7 +88,7 @@ const WorkerTargetActor = protocol.ActorClassWithSpec(workerTargetSpec, {
       if (isServiceWorker) {
         this._preventServiceWorkerShutdown();
       }
-      this._dbg.addListener(this);
+      this._dbg.addListener(this._dbgListener);
       this._attached = true;
     }
 
@@ -152,7 +157,7 @@ const WorkerTargetActor = protocol.ActorClassWithSpec(workerTargetSpec, {
     return { type: "pushed" };
   },
 
-  onClose() {
+  _onWorkerClose() {
     if (this._attached) {
       this._detach();
     }
@@ -160,7 +165,7 @@ const WorkerTargetActor = protocol.ActorClassWithSpec(workerTargetSpec, {
     this.conn.sendActorEvent(this.actorID, "close");
   },
 
-  onError(filename, lineno, message) {
+  _onWorkerError(filename, lineno, message) {
     reportError("ERROR:" + filename + ":" + lineno + ":" + message + "\n");
   },
 
@@ -194,7 +199,7 @@ const WorkerTargetActor = protocol.ActorClassWithSpec(workerTargetSpec, {
       this._allowServiceWorkerShutdown();
     }
 
-    this._dbg.removeListener(this);
+    this._dbg.removeListener(this._dbgListener);
     this._attached = false;
   },
 

devtools/shared/transport/worker-transport.js

@@ -13,27 +13,28 @@
  * A transport that uses a WorkerDebugger to send packets from the main
  * thread to a worker thread.
  */
-function MainThreadWorkerDebuggerTransport(dbg, id) {
-  this._dbg = dbg;
-  this._id = id;
-  this.onMessage = this._onMessage.bind(this);
-}
+class MainThreadWorkerDebuggerTransport {
+  constructor(dbg, id) {
+    this._dbg = dbg;
+    this._id = id;
 
-MainThreadWorkerDebuggerTransport.prototype = {
-  constructor: MainThreadWorkerDebuggerTransport,
+    this._dbgListener = {
+      onMessage: this._onMessage.bind(this),
+    };
+  }
 
-  ready: function() {
-    this._dbg.addListener(this);
-  },
+  ready() {
+    this._dbg.addListener(this._dbgListener);
+  }
 
-  close: function() {
-    this._dbg.removeListener(this);
+  close() {
+    this._dbg.removeListener(this._dbgListener);
     if (this.hooks) {
       this.hooks.onClosed();
     }
-  },
+  }
 
-  send: function(packet) {
+  send(packet) {
     this._dbg.postMessage(
       JSON.stringify({
         type: "message",
@@ -41,23 +42,21 @@ MainThreadWorkerDebuggerTransport.prototype = {
         message: packet,
       })
     );
-  },
+  }
 
-  startBulkSend: function() {
+  startBulkSend() {
     throw new Error("Can't send bulk data from worker threads!");
-  },
+  }
 
-  _onMessage: function(message) {
+  _onMessage(message) {
     const packet = JSON.parse(message);
-    if (packet.type !== "message" || packet.id !== this._id) {
+    if (packet.type !== "message" || packet.id !== this._id || !this.hooks) {
       return;
     }
 
-    if (this.hooks) {
-      this.hooks.onPacket(packet.message);
-    }
-  },
-};
+    this.hooks.onPacket(packet.message);
+  }
+}
 
 exports.MainThreadWorkerDebuggerTransport = MainThreadWorkerDebuggerTransport;