proxy: do not throw on event binding. see nodejs/node#26463.

lib/internal/proxy.js

@@ -27,7 +27,7 @@ class EventProxy {
         if (this.dom)
           this.target[`on${name}`] = handler;
         else
-          this.target.addListener(name, handler);
+          addListener(this.target, name, handler);
       }
     }
 
@@ -42,7 +42,7 @@ class EventProxy {
         if (this.dom)
           this.target[`on${name}`] = null;
         else
-          this.target.removeListener(name, handler);
+          removeListener(this.target, name, handler);
       }
     }
 
@@ -104,6 +104,37 @@ class EventProxy {
   }
 }
 
+/*
+ * Helpers
+ */
+
+function addListener(ee, name, handler) {
+  try {
+    ee.addListener(name, handler);
+  } catch (e) {
+    if (!isCloseError(name, e))
+      throw e;
+  }
+}
+
+function removeListener(ee, name, handler) {
+  try {
+    ee.removeListener(name, handler);
+  } catch (e) {
+    if (!isCloseError(name, e))
+      throw e;
+  }
+}
+
+function isCloseError(name, err) {
+  if (name !== 'message')
+    return false;
+
+  // Node throws when trying to unbind `message` from a closed port.
+  // See: https://github.com/nodejs/node/issues/26463
+  return err && err.message === 'Cannot send data on closed MessagePort';
+}
+
 /*
  * Expose
  */

test/threads-test.js

@@ -933,4 +933,14 @@ describe(`Threads (${threads.backend})`, (ctx) => {
     thread.on('error', cb);
     thread.on('exit', onExit(cb, () => called, 0));
   });
+
+  it('should not throw on unbind after close', () => {
+    const {port1, port2} = new threads.Channel();
+    const fn = () => {};
+
+    port1.on('message', fn);
+    port1.close(() => {
+      port1.off('message', fn);
+    });
+  });
 });