How to solve "TypeError: fn is not a function"?

Question

I'm trying to implement Passport.JS and JWT functionality into my nodejs application and receive the following error

TypeError: fn is not a function

in this code block of my application

const utils = require('./utils')
const strategies = require('./strategies')

const pipe = (...functions) => args => functions.reduce((arg, fn) => fn(arg), args)

const initialiseAuthentication = app => {
  utils.setup()

  pipe(strategies.JWTStrategy)(app)
}

module.exports = { utils, initialiseAuthentication, strategies }

Would be awesome if someone could guide me in the right direction, as I am stuck here. Thank you a lot.

Answer 1

Found the issue myself. In the /strategies/index.js file I was exporting the strategy like so module.exports = { strategy }, but was calling pipe(strategies.JWTStrategy)(app) in the code snippet.

It has to be pipe(strategies.strategy)(app).