Emit close event when the server closes

docs/api.md

@@ -33,6 +33,10 @@ Emitted each time a socket is connected but is not handled by any handlers. By d
 
 Emitted each time a socket is connected and handled by a handler.
 
+### Event: 'close'
+
+Emitted when the server closes.
+
 ### server.createHandler(options)
 
 - `options` `<Object>`
@@ -44,7 +48,9 @@ If any of these three attributes is passed to `options` an error will be thrown.
 
 Returns a new [`WebSocket.Server`](https://github.com/websockets/ws/blob/master/doc/ws.md#class-websocketserver) instance of `ws`. Please refer the the `ws` documentation for more information on this.
 
-### server.close()
+### server.close([callback])
+
+- `callback` `<function>`
 
 Stops the server from accepting new connections.
 

lib/MultipathServer.js

@@ -7,7 +7,9 @@ const { inherits } = require('util');
 const { invariant, withoutProperties } = require('./utils');
 const { createHandlerCreator } = require('./createHandlerCreator');
 const { rejectSocket } = require('./rejectSocket');
+const { delegateEmittedEvents } = require('./delegateEmittedEvents');
 
+const HTTP_EVENTS_TO_EXPOSE = ['close'];
 const PRIVATE_ATTRS = ['port', 'autoListen'];
 
 const defaults = {
@@ -31,6 +33,8 @@ function MultipathServer(options) {
   const handlers = {};
   const server = createServer();
 
+  delegateEmittedEvents(HTTP_EVENTS_TO_EXPOSE, server, this);
+
   // Handle an HTTP upgrade request by delegating that request to the proper
   // websocket server if it exists
   server.on('upgrade', (request, socket, head) => {

lib/delegateEmittedEvents.js

@@ -0,0 +1,17 @@
+'use-strict';
+
+/**
+ * Delegate events emitted from one EventEmitter to another
+ * @param {Array<string>} events Events to be delegated
+ * @param {EventEmitter} source Original EventEmitter to listen to
+ * @param {EventEmitter} target Target EventEmitter to emit events of the source
+ */
+function delegateEmittedEvents(events, source, target) {
+  for (let event of events) {
+    source.on(event, (...args) => target.emit(event, ...args));
+  }
+}
+
+module.exports = {
+  delegateEmittedEvents,
+};

test/MultipathServer.test.js

@@ -90,6 +90,12 @@ describe('MultipathServer', () => {
     });
   });
 
+  it('emits close event', (done) => {
+    createMultipathServer();
+    server.on('close', done);
+    server.close();
+  });
+
   it('throws when creating duplicate handlers', () => {
     createMultipathServer();
     server.createHandler({ path: '/foo' });