如何将用于身份验证的中间件功能从主服务器模块传递到路由器文件

Question

Somewhat new, please bear with me. Trying to use passport to authenticate only specific routes in a website. The routes are in a separate file called blog_a.js . I have the following functions created in the main server.js file:

function checkAuthenticated(req, res, next) {
    if (req.isAuthenticated()){
        return next()
    }
    res.redirect('/login')
}

function checkNotAuthenticated(req, res, next) {
    if (req.isAuthenticated()){
        return res.redirect('/')
    }
    next()
}

However, I'm trying to pass the above functions into the blog_a.js module, so I can use them as middleware to protect the routes within that module.

I have tried to use module.exports = {checkAuthenticated, checkNotAuthenticated} at the bottom of the main 'server.js' file, and then use a let server = require('../server.js') line to import these functions to the module that contains the routes I want to protect.

However, the above server variable comes back as undefined, and I've tried several permutations / destructuring methods to try to import it. All to no avail, I keep getting the routes failing due to the "undefined" object-- Error: Route.get() requires a callback function but got a [object Undefined] .

How can I set up the authentication in the server.js file but then pass its authentication functions to be used as middleware within an individual route file?

I looked at this solution , but it doesn't clearly explain how to get the middleware functions from one module-- server.js --to another module-- blog_a.js .

Answer 1

I got the following response on Patreon from Kyle of Web Dev Simplified, and it worked like a charm!

"You should be able to just create another file that is called authMiddleware.js or something like that. Then in that file define and export the functions at the end (module.exports = { function1, function2 }). Now in the places you need those functions you should be able to import them like so (const { function1, function2 } = require('./authMiddleware'))."

So I followed Kyle's advice and created the following separate file authMiddleware.js :

function checkAuthenticated(req, res, next) {
    if (req.isAuthenticated()){
        return next()
    }
    res.redirect('/login')
}

function checkNotAuthenticated(req, res, next) {
    if (req.isAuthenticated()){
        return res.redirect('/')
    }
    next()
}

module.exports = { checkAuthenticated, checkNotAuthenticated }

... and then used the following require statements to get access to the functions:

-in main server.js --> const {checkAuthenticated, checkNotAuthenticated} = require('./authMiddleware.js')

-in router file blog_a.js --> const {checkAuthenticated, checkNotAuthenticated} = require('../authMiddleware.js')

Thanks!