fix: timed out streams should be destroyed on timeout event

Author: mbroadst

lib/cmap/connection.js

@@ -54,6 +54,10 @@ class Connection extends EventEmitter {
     });
 
     stream.on('close', () => {
+      if (this.closed) {
+        return;
+      }
+
       this.closed = true;
       this[kQueue].forEach(op =>
         op.cb(new MongoNetworkError(`connection ${this.id} to ${this.address} closed`))
@@ -64,6 +68,11 @@ class Connection extends EventEmitter {
     });
 
     stream.on('timeout', () => {
+      if (this.closed) {
+        return;
+      }
+
+      stream.destroy();
       this.closed = true;
       this[kQueue].forEach(op =>
         op.cb(new MongoNetworkError(`connection ${this.id} to ${this.address} timed out`))
@@ -106,6 +115,10 @@ class Connection extends EventEmitter {
     return this[kClusterTime];
   }
 
+  get stream() {
+    return this[kStream];
+  }
+
   markAvailable() {
     this[kLastUseTime] = Date.now();
   }

test/unit/cmap/connection.test.js

@@ -38,4 +38,34 @@ describe('Connection', function() {
       }
     );
   });
+
+  it('should destroy streams which time out', function(done) {
+    server.setMessageHandler(request => {
+      const doc = request.document;
+      if (doc.ismaster) {
+        request.reply(mock.DEFAULT_ISMASTER_36);
+      }
+
+      // blackhole all other requests
+    });
+
+    connect(
+      Object.assign({ bson: new BSON(), connectionType: Connection }, server.address()),
+      (err, conn) => {
+        expect(err).to.not.exist;
+        expect(conn).to.exist;
+
+        conn.command('$admin.cmd', { ping: 1 }, { socketTimeout: 50 }, (err, result) => {
+          expect(err).to.exist;
+          expect(result).to.not.exist;
+
+          expect(conn)
+            .property('stream')
+            .property('destroyed').to.be.true;
+
+          done();
+        });
+      }
+    );
+  });
 });