Server-side authentication higher order functions

server-side-auth.js

import nookies from 'nookies'

class ServerSideAuth {
  static #key = 'token'

  static #cookies = nookies

  static #isAuthenticated = token => {
    const response = fetch('http://localhost:3000/api/me', {
      headers: {
        authorization: `Bearer ${token}`,
      },
    })

    return response.status !== 401
  }

  static #execute = async (context, fn) => {
    if (typeof fn === 'function') {
      const payload = await fn(context)

      if (payload) {
        return payload
      }
    }

    return {
      props: {},
    }
  }

  static withPublic = fn => async context => {
    const cookies = ServerSideAuth.#cookies.get(context)

    if (cookies.token) {
      const isAuthenticated = ServerSideAuth.#isAuthenticated(cookies.token)

      if (!isAuthenticated) {
        ServerSideAuth.#cookies.destroy(context, ServerSideAuth.#key)
      }
    }

    return ServerSideAuth.#execute(context, fn)
  }

  static withAuthFlow = fn => async context => {
    const cookies = ServerSideAuth.#cookies.get(context)

    if (cookies.token) {
      const isAuthenticated = ServerSideAuth.#isAuthenticated(cookies.token)

      if (isAuthenticated) {
        return {
          redirect: {
            destination: '/dashboard',
          },
        }
      }

      ServerSideAuth.#cookies.destroy(context, ServerSideAuth.#key)
    }

    return ServerSideAuth.#execute(context, fn)
  }

  static withPrivate = fn => async context => {
    const cookies = ServerSideAuth.#cookies.get(context)

    if (!cookies.token) {
      return {
        redirect: {
          destination: '/login',
        },
      }
    }

    const isAuthenticated = ServerSideAuth.#isAuthenticated(cookies.token)

    if (!isAuthenticated) {
      ServerSideAuth.#cookies.destroy(context, ServerSideAuth.#key)

      return {
        redirect: {
          destination: '/login',
        },
      }
    }

    return ServerSideAuth.#execute(context, fn)
  }
}

export default ServerSideAuth