fix hanging when attempting to write to a closed pipe

Author: kevzoid

lib/stdio-wrapper.js

@@ -39,7 +39,10 @@ class StdioWrapper extends EventEmitter {
         this._pendingMessage = '';
         this._eventListeners = [
             addEventListener(pipeRead, 'data', buffer => this._dispatch(buffer)),
-            addEventListener(pipeRead, 'close', () => this.emit('close')),
+            addEventListener(pipeRead, 'close', () => {
+                this._pipeWrite = null;
+                this.emit('close');
+            }),
             addEventListener(pipeRead, 'error', (err) => this.emit('error', err)),
             addEventListener(pipeWrite, 'error', (err) => this.emit('error', err)),
         ];
@@ -48,6 +51,8 @@ class StdioWrapper extends EventEmitter {
 
     send(message, callback) {
         try {
+            if (!this._pipeWrite)
+                throw new Error('CDP pipeWrite closed');
             this._pipeWrite.write(message);
             this._pipeWrite.write('\0');
             callback();