nodeJS代码模式=> Express中间件/ Oauth2 / Passport

Question

I inherited a codebase where it looks like they run middleware in node with the following pattern for Oauth2 passport strategy

module.exports = function (router) {
   router.get('/', function (req, res, next) {
       passport.authenticate('type', object, function(err, info) {

             //pass info object to next middleware

  })(req,res,next) <---where does this go?!?
})
}

From my current understanding of the code base, this is actually the last function call in the middleware chain, so could I just add a piece of middleware to the bottom?

Does this sound like the right idea?

And just to clarify what I'm trying to do:

1. pass data from Oauth callback through middleware function by attaching it to the req
2. perform DB business logic (create or lookup account)
3. login with JWT
4. redirect

Answer 1

This appears to be the "custom callback" method of using passport's authenticate function. If you look at the documentation you can see how they expect it to be used. That said, I don't know what that second argument is supposed to be doing (the object ) - it looks like a variable, but I don't see it defined anywhere, and I'm not sure the authenticate method takes arguments in that manner. Also, the custom callback takes three arguments: err , user , and then info ... which might trip you up.

Okay, so now to your actual question of "could I just add a piece of middleware to the bottom?" Sort of? The fact is, you're in a routing middleware at that point. If it matches and auth is successful, then you should do whatever code for that route is required inside the custom callback. That's the point of this way of doing things. Alternatively you could use passport.authenticate as a piece of middleware itself (it returns a middleware function usable in the CommonJS pattern.

If you don't want to change up the code, then you could just do this:

module.exports = function (router) {
  router.get('/', function (req, res, next) {
    passport.authenticate('PICK A VALID TYPE', function(err, user, info) {

       // this custom callback will be executed once auth completes
       // (either successfully or not

       // put code in here to perform DB business logic, login, and redirect

    })(req,res,next); <--- this executes the passport.authenticate middleware
  })
};