How to solve "secretOrPrivateKey must have a value" in Node.js

I was writing an awesome stuff with Express today and I ran into an error, after solving it (thanks to some wonderful geeks on Stackoverflow) I thought it best to write about it just incase anyone runs into this same error in future this article will kind them on how to solve it.

what is the error and why did it occur?

I installed the dotenv dependency with the aim of storing my json web token secret inside it so as to avoid pushing a secret pass to a Github public repo.

Initially, I had put the connection pass of my MongoDB database in it with the name DB_DETAILS and I wanted to add my token secret in the next line. Well, I did just that and boooom! the terminal threw me an error warning at run time.

UnhandledPromiseRejectionWarning: Error: secretOrPrivateKey must have a value
at Object.module.exports as sign

How did I solve this?

You'd be amazed! I only had to replace process.env.TOKEN_SECRET to ${process.env.TOKEN_SECRET} using ES6 String Literals.

Yes, that worked for me. Go ahead and try it out.

explicitly configure dotenv in NestJS to solve error

Ooooh, oh! Since NestJS uses dotenv under the hood, you could easily use ConfigService or configure dotenv by changing some files.

jwt.strategy.ts

import * as dotenv from 'dotenv';
dotenv.config();

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {
  constructor() {
    super({
      secretOrKey: process.env.TOKEN_SECRET,
    });
  }
}

auth.module.ts

import * as dotenv from 'dotenv';
dotenv.config();

@Module({
  imports: [
    JwtModule.register({
      secret: process.env.JWT_SECRET,
    }),
  ],
})

Let me know in the comments if it works for you!