Cannot read properties of undefined (reading 'decode') NestJs

Question

I'm trying to get the information stored in my jwt in Nestjs.But I'm getting the following error

[Nest] 16960 - 19/12/2022, 10:22:28 pm ERROR [ExceptionsHandler] Cannot read properties of undefined (reading 'decode') TypeError: Cannot read properties of undefined (reading 'decode')
at AdminGuard.canActivate (D:\Noum\Data\CYBRNODE\MAN STACK\Cybrnode-Blog-Backend\Cybr-Blog-Nest-Backend\src\guard\admin.guard.ts:28:34)

at GuardsConsumer.tryActivate (D:\Noum\Data\CYBRNODE\MAN STACK\Cybrnode-Blog-Backend\Cybr-Blog-Nest-Backend\node_modules@nestjs\core\guards\guards-consumer.js:15:34) at processTicksAndRejections (node:internal/process/task_queues:96:5)

code

export type PayloadType = {
      id: string;
    };

code. I can see that token is present through console

  let jwtService: JwtService;

    let token = AuthenticationService.jwtToken.accessToken;
    console.log(token);

    if (token) {
      const payload = jwtService.decode(token.split('')[1]) as PayloadType;
      console.log(payload);

    }

Answer 1

Always make sure the Imports

I was using

import { JwtService } from '@nestjs/jwt';

But according to @mh377 the following import is used to decode

import * as jwt from 'jsonwebtoken';

Example according to my code

let token = AuthenticationService.jwtToken;

    var { header, payload, signature } = jwt.decode(token.accessToken, {
      complete: true,
    });
    console.log('ID', payload.sub);