[fix] Resume the socket in the CLOSING state

When the value of the `readyState` attribute is `CLOSING`, the internal
socket might still be open. Resume it to read any remaining data and to
allow the connection to be closed cleanly.

Author: lpinca

lib/stream.js

@@ -152,7 +152,10 @@ function createWebSocketStream(ws, options) {
   };
 
   duplex._read = function () {
-    if (ws.readyState === ws.OPEN && !resumeOnReceiverDrain) {
+    if (
+      (ws.readyState === ws.OPEN || ws.readyState === ws.CLOSING) &&
+      !resumeOnReceiverDrain
+    ) {
       resumeOnReceiverDrain = true;
       if (!ws._receiver._writableState.needDrain) ws._socket.resume();
     }

test/create-websocket-stream.test.js

@@ -538,5 +538,31 @@ describe('createWebSocketStream', () => {
         });
       });
     });
+
+    it('resumes the socket if `readyState` is `CLOSING`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        ws.on('message', () => {
+          assert.ok(ws._socket.isPaused());
+
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+
+          duplex.end();
+
+          process.nextTick(() => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+            duplex.resume();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send(randomBytes(16 * 1024));
+      });
+    });
   });
 });