TypeError: Cannot read property 'sign' of undefined [JWT / Nestjs / e2e tests]

Question

I need to generate a Jwt Bearer Token for my e2e tests. As the process it a bit tedious, and because that's not what I am trying to test, I'd like to bypass it by directly getting instead of going through the 2FA real process.

Unfortunately I keep getting the following error:

 TypeError: Cannot read property 'sign' of undefined

      150 |
      151 |     function getBearerToken(candidateId: number) {
    > 152 |       return jwtService.sign({ sub: candidateId.toString() })
          |                         ^
      153 |     }
      154 |   })
      155 | })

      at getBearerToken (app.e2e-spec.ts:152:25)
      at Object.<anonymous> (app.e2e-spec.ts:127:21)

describe('Bookmarks Module', () => {
    let bearerToken: string
    let jwtService: JwtService

    beforeEach(() => {
      bearerToken = getBearerToken(1)
      jwtService = new JwtService({
        secret: process.env.JWT_SECRET,
        signOptions: { expiresIn: '1h' },
      })
    })

    test('/v1/bookmarks/ (GET) [auth]', () => {
      return expectCorrectAuthenticatedGetResponse(
        `${V1_PREFIX}/bookmarks/`,
        bearerToken
      )
    })

    test('/v1/bookmarks/{id} (POST) [auth]', () => {
      const DATA = { offerId: 19 }
      return expectCorrectAuthenticatedPostResponse(
        `${V1_PREFIX}/bookmarks/${DATA.offerId}`,
        DATA,
        bearerToken
      )
    })

    function getBearerToken(candidateId: number) {
      return jwtService.sign({ sub: candidateId.toString() })
    }
  })

I'm not sure about it but aren't you required to `JwtModule.register` first? — Nir Alfasi, Oct 07 '20 at 10:42

score 1 · Accepted Answer · answered Oct 07 '20 at 11:54

You call jwtService.sign() in getBearerToken() which is itself called in beforeEach(), just before jwtService is initialized. So jwtService is still undefined when you try to use it. You should invert the lines in beforeEach():

    beforeEach(() => {
      jwtService = new JwtService({
        secret: process.env.JWT_SECRET,
        signOptions: { expiresIn: '1h' },
      })
      bearerToken = getBearerToken(1)
    })

score 1 · Answer 2 · edited Apr 27 '23 at 23:23

1

I have faced the same issue when I import jwt like:

import { jwt } from "jsonwebtoken";

So I changed it to:

var jwt = require('jsonwebtoken');

or

import jwt from "jsonwebtoken";

and it worked it

I don't know why it worked.

edited Apr 27 '23 at 23:23

1.21 gigawatts

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answered Mar 26 '23 at 00:55

Isaacs Katongole

331
2
5

Same thing. I have been trying to use ES6 modules and when I imported using the destructuring it gave this error. But using `require` or excluding the curly braces made it work again. – 1.21 gigawatts Apr 27 '23 at 23:26

TypeError: Cannot read property 'sign' of undefined [JWT / Nestjs / e2e tests]

2 Answers2