I try to port an application to NestJS but I have not found the 'NestJS way' of listening for a successful server connection.
From the old app
server.on('listening', async function (): Promise<void> {
...
});
In the new app I currently have placed some code after the listen call...
await app.listen(options.port);
// do anything when the server listens
...but that's not the same as an event handler. I don't know if 'listen' events can come multiple times (reconnects?!) but there has to be a way to listen for that event for example decoupled in other code parts?!
In the docs I have found the onApplicationBootstrap() lifecycle hook method but that's called "once all modules have been initialized, but before listening for connections."
I thought about getting the HttpAdapter or Server ask if it is instanceof ExpressAdapter and do something like .on('listen',... when I find the right instance, but at least in the @types I haven't found the right way of doing this and it smells like a hack.
Can someone please point me to the place in the docs or show me how to do this preferably in an adapter-agnostic NestJS way? Seems like I search for the wrong things.
It's not the getHttpAdapter but getHttpServer!
The important parts are
const app = await NestFactory.create<NestExpressApplication>(AppModule);
const serverInstance = app.getHttpServer() as Server;
serverInstance.on('listening', ...);
Unfortunately app.getHttpServer returns an object of type any. app.listen returns the same instance but the type is Server.