Compatibility with FastifyAdapter

[mhavelant]

I'm submitting a...

[ ] Regression 
[?] Bug report
[?] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

Using the "FastifyAdapter" the server fails to start with the message

UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'listeners' of undefined

Expected behavior

The server starts and the added health check URLs are available.

Minimal reproduction of the problem with instructions

App:

• Basic setup of nest from the first-steps docs
  • index.ts with app = nestfactory.create() and app.listen,
  • app.module;
    • controllers: app.controller, which has a single @get(/hello) route
    • imports: HealthModule, that's the same as the one in the README, but DatabaseHealthIndicator replaced with DNSHealthIndicator which pings google

This start like expected:
const app = await NestFactory.create(AppModule); await app.listen(20000);

This fails with the mentioned error:
const app = await NestFactory.create(AppModule, new FastifyAdapter()); await app.listen(20000);

Note:

• When using fastify/fastify with godaddy/terminus it works with this: createTerminus(fastify.server, options); (everything else is just copy/paste from their respective READMEs)

What is the motivation / use case for changing the behavior?

Nest provides FastifyAdapter by default, nestjs/terminus should be compatible with it.

Environment

Nest version: 5.5.1

 
For Tooling issues:
- Node version: 10.14.2  
- Platform: Linux running docker, image: 10.14.2-alpine ; but also Linux running 10.13.0 directly

Others:

[mhavelant]

Small note: Using createTerminus(app.getHttpAdapter().getHttpServer(), terminusOptions); will register the routes for the server (but not for nest, so it's kinda pointless, but at least more info for the maintainers).

[BrunnerLivio]

Thanks a lot for reporting!

getHttpServer() won't work as far as I know in a TestModuleContext. nestjs/nest#1282

Therefore I needed to change to ApplicationReferenceHost.
Seems like ApplicationReferenceHost provided by @nestjs/core does not provide a HttpServer when using Fastify.

I was able to reproduce the error by adding a FastifyAdapter e2e test case.
Travis fails with: Cannot read property 'listeners' of undefined, therefore ApplicationReferenceHost.applicationRef.httpServer must be null

https://travis-ci.org/nestjs/terminus/builds/470600392#L717

terminus/lib/terminus-bootstrap.service.ts

Line 146 in ca5bef4

this.httpServer = this.refHost.applicationRef.httpServer;

I created an issue on the nestjs repository
nestjs/nest#1391

[BrunnerLivio]

Fixed with 5.5.2