Reading PORT number from .env file in nestjs

I have details defined in .env file. Below is my code.

import { Module } from '@nestjs/common';
import { MailService } from './mail.service';
import { MailController } from './mail.controller';
import { MailerModule } from '@nestjs-modules/mailer';
import { HandlebarsAdapter}  from '@nestjs-modules/mailer/dist/adapters/handlebars.adapter';
import { join } from 'path';


@Module({
  imports:[
     MailerModule.forRoot({
      transport:{
        host: process.env.SMTP_HOST,
        port: 1025,
        ignoreTLS: true,
        secure: false,
        auth:{
          user:'[e-mail]',
          pass:'Ddixit90@@',
        },
      },
      defaults:{
           from: '"No Reply" <no-reply@localhost>',
      },
      template:{
        dir:join(__dirname,'templates'),
        adapter: new HandlebarsAdapter(),
        options:{
          strict:false,
        },
      }
     }
      
     )
  ],
  controllers: [MailController],
  providers: [MailService],
  exports:[MailService]
})
export class MailModule {}

host: process.env.SMTP_HOST is working properly. but when I am writing process.env.SMTP_PORT it is saying you can not assign string to number.

when I wrote parseInt(process.env.SMTP_PORT) it is still not working. how to assign port from .env file

Answer

port: +process.env.SMTP_PORT should work casting it to a number. If there is something different, perhaps share the error you are getting.

An alternative would be to use the config service for the MailerModule and use the factory. Here is an example implementation of that:

MailerModule.forRootAsync({
            useFactory: async (config: ConfigService) => ({
                transport: {
                    host: process.env.SMTP_HOST,
                    port: 1025,
                    ignoreTLS: true,
                    secure: false,
                    auth: {
                        user: "[e-mail]",
                        pass: "Ddixit90@@",
                    },
                },
                defaults: {
                    from: '"No Reply" <no-reply@localhost>',
                },
                template: {
                    dir: join(__dirname, "templates"),
                    adapter: new HandlebarsAdapter(),
                    options: {
                        strict: false,
                    },
                },
            }),
            inject: [ConfigService],
        }),

Doing it this way, config.get is able to determine the type by the property. Else you can define it with config.get<number>