Error: metatype is not a constructor when using instance of own HTTPS Server class - node.js

Question

Good evening, I am playing around with nest and want to achieve an own HTTPS-Server that can be instantiated everywhere in other projects. Right at the beginning I get the following error-message:
TypeError: metatype is not a constructor
… when I init the following HTTPS-Server:
import { Injectable } from '#nestjs/common';
import { NestFactory } from '#nestjs/core';
import { FastifyAdapter, NestFastifyApplication } from '#nestjs/platform-fastify';
import * as fs from 'fs';
#Injectable()
export class HttpsServer {
constructor() {}
async bootstrap() {
const httpsOptions = {
key: fs.readFileSync('./certs/server.key'),
cert: fs.readFileSync('./certs/server.cert'),
};
const app = await NestFactory.create<NestFastifyApplication>(
new FastifyAdapter({ https: httpsOptions }),
);
await app.listen(443);
}
}
like this:
import { Logger } from '#nestjs/common';
import { HttpsServer } from 'server-lib';
const logger = new Logger();
const app = new HttpsServer();
app.bootstrap().then(() => {
logger.log('Bootstrap complete!');
}).catch((error) => {
logger.log('Bootstrap failed: ', error);
process.exit(1);
});
Thx for help...

Answer 1

All Nest applications needs to have a "RootModule" of some sort. With nest new applications this is a AppModule. This class holds the metadata for the server for how to tie everything together and run. What you could probably do is modify your HttpModule's constructor to do something like
export class HttpsServer {
constructor(private readonly rootModule: Type<any>) {} // Type comes from #nestjs/common
async bootstrap() {
const httpsOptions = {
key: fs.readFileSync('./certs/server.key'),
cert: fs.readFileSync('./certs/server.cert'),
};
const app = await NestFactory.create<NestFastifyApplication>(
this.rootModule,
new FastifyAdapter({ https: httpsOptions }),
);
await app.listen(443);
}
}
So now when you call new HttpServer() you pass in the root module and have everything else already set up. The NestFactory will instantiate the metadata from there properly, and you'll use the FastifyAdapter.
For more information, I suggest you follow the docs overview to get a feeling of how these classes fit together and why they're needed.

Answer 2

You probably have used an incorrect guard.
Check #UseGuards() and use the correct guard for that function.

Answer 3

If you're importing some files from index in the same folder such as all entities as
import * as Entities from './entities
make sure that you have that ./entities in the folder path and just plan '.'
It does not throws error but while building this is not recognized. use the full file path and it will most probably solve the issue.