NestJS Authentication - Passport strategy, JWT creation problem - authentication

Question

I'm following the official NestJS documentation. Currently, I'm trying to implement the authentication step with Passport strategy. I did every step, as the documentation says, but I got stuck where I need to generate the JWT with the jwtService.sign() method.
The error, that I'm getting is:
ERROR [ExceptionsHandler] secretOrPrivateKey must have a value`.
Here are the code snippets:
AuthModule:
#Module({
imports: [
UserModule,
PassportModule,
User,
TypeOrmModule.forFeature([User]),
JwtModule.register({
secret: 'somerandomsecret',
signOptions: { expiresIn: '60s' }
})
],
providers: [AuthService, LocalStrategy, UserService],
exports: [AuthService]
})
export class AuthModule {}
AuthService
#Injectable()
export class AuthService {
constructor(
private userService: UserService,
private jwtService: JwtService
){}
async validateUser(email: string, pass: string): Promise<any> {
const user = await this.userService.findByEmail(email);
const isMatch = await comparePasswords(pass, user.password);
if( user && isMatch) {
const { password, ...result } = user;
return result;
}
return null;
}
async signIn(user: any) {
const payload = { username: user.email, sub: user.id };
return this.jwtService.sign(payload)
}
}
And inside the User controller, I'm calling the method signIn from the AuthService.
UserController
import {
Body,
Controller,
Post,
HttpException,
HttpStatus,
Request,
UseGuards,
Bind,
} from "#nestjs/common";
import { UserService } from "./user.service";
import { SignUpDataValidation } from "./user.validation";
import { hashPassword } from "../../utils/hash-password";
import { AuthGuard } from '#nestjs/passport';
import { AuthService } from '../auth/auth.servers';
import { LocalAuthGuard } from '../auth/local-auth.guard';
#Controller("user")
export class UserController {
constructor(
private userService: UserService,
private authService: AuthService
) {}
#UseGuards(LocalAuthGuard)
#Post("/signin")
#Bind(Request())
async signIn(req) {
return this.authService.signIn(req.user)
}
}
UserModule
import { Module } from "#nestjs/common";
import { UserController } from "./user.controller";
import { UserService } from "./user.service";
import { TypeOrmModule } from "#nestjs/typeorm";
import { User } from "src/modules/user/user.entity";
import { AuthService } from '../auth/auth.servers';
import { JwtService } from '#nestjs/jwt';
#Module({
imports: [TypeOrmModule.forFeature([User])],
controllers: [UserController],
providers: [UserService, AuthService, JwtService],
})
export class UserModule {}
LocalStrategy
import { Injectable, UnauthorizedException } from '#nestjs/common';
import { PassportStrategy } from '#nestjs/passport';
import { Strategy } from 'passport-local';
import { AuthService } from './auth.servers';
#Injectable()
export class LocalStrategy extends PassportStrategy(Strategy) {
constructor(private authService: AuthService) {
super({usernameField: 'email'});
}
async validate(email: string, password: string): Promise<any> {
const user = await this.authService.validateUser(email,
password);
if(!user) {
throw new UnauthorizedException()
}
return user;
}
}
As you can see, I'm also using Guards, but I'm not going to send you that code to avoid confusion.
So, can anybody tell me, why I'm getting this ERROR? Am I missing something?
Here is the link to the particular NestJS documentation page with a feature that I'm trying to implement: https://docs.nestjs.com/security/authentication