Merge pull request #13 from laggingreflex/attach

use existing app.server

README.md

@@ -48,7 +48,7 @@ app.server.listen( process.env.PORT || 3000 )
 
 ## Attaching to existing projects
 
-The `attach` function is used to attach the `IO` instance to the application, this adds `server` and `io` properties to the koa application and should happen before the app starts listening on a port.
+The `attach` function is used to attach the `IO` instance to the application, this adds `server`\* and `io` properties to the koa application and should happen before the app starts listening on a port. \*If `app.server` already exists (as an http server), it uses that instead.
 
 The only change you need to make to your existing code is to start the server listening by calling `app.server.listen` rather than `app.listen` (you’ll get a console warning if you get it wrong ;) ).
 

index.js

@@ -97,7 +97,25 @@ module.exports = class IO {
    * @param app <Koa app> the koa app to use
    */
   attach( app ) {
-    if ( app.server || app._io ) {
+
+    if ( app.server && app.server.constructor.name != 'Server' ) {
+      throw new Error( 'app.server already exists but it\'s not an http server' );
+    }
+
+    if ( !app.server ) {
+      // Create a server if it doesn't already exists
+      app.server = http.createServer( app.callback() )
+
+      // Add warning to conventional .listen
+      // @TODO should this just be removed?
+      app.__listen = app.listen
+      app.listen = function listen() {
+        console.warn( 'IO is attached, did you mean app.server.listen()' )
+        return app.__listen.apply( app, arguments )
+      }
+    }
+
+    if ( app._io ) {
       // Without a namespace we’ll use the default, but .io already exists meaning
       // the default is taken already
       if ( !this.opts.namespace ) {
@@ -108,19 +126,10 @@ module.exports = class IO {
       return
     }
 
-    // Add warning to conventional .listen
-    // @TODO should this just be removed?
-    app.__listen = app.listen
-    app.listen = function listen() {
-      console.warn( 'IO is attached, did you mean app.server.listen()' )
-      return app.__listen.apply( app, arguments )
-    }
-
     if ( this.opts.hidden && !this.opts.namespace ) {
       throw new Error( 'Default namespace can not be hidden' )
     }
 
-    app.server = http.createServer( app.callback() )
     app._io = new socketIO( app.server, this.opts.ioOptions )
 
     if ( this.opts.namespace ) {

spec/attach.test.js

@@ -35,7 +35,18 @@ tape( 'should not alter a koa app that already has ._io unless called with a nam
   }, null, 'calling .attach throws an error when ._io already exists without a namespace' )
 })
 
-tape( 'should not alter a koa app that already has .server', t => {
+tape( 'should work with koa app that already has .server', t => {
+  t.plan( 1 )
+
+  const app = new Koa()
+  const socket = new IO()
+  app.server = http.createServer()
+  socket.attach( app )
+
+  t.ok( app.io, 'socket is attached to koa app' )
+})
+
+tape( 'shouldn\'t work if app.server exists but it\'s not an http server', t => {
   t.plan( 1 )
 
   const app = new Koa()
@@ -44,7 +55,7 @@ tape( 'should not alter a koa app that already has .server', t => {
 
   t.throws( () => {
     socket.attach( app )
-  }, null, 'calling .attach throws an error when .server already exists' )
+  }, null, 'calling .attach throws an error when .server already exists but it\'s not an http server' )
 })
 
 tape( 'Attaching a namespace to a koa app with socket.io existing is all cool', t => {