如何使用POST路由作为中间件

Question

I have 2 routes

1. users.js POST api/users
2. auth.js POST api/auth/confirmation

I want to use auth/confirmation as middleware in route /users

I have tried creating a temporary function and using res.redirect(...) but it throws error Cannot GET ....

I can change the structure of the program to make it work, but I want to make it work this way by using another route as a middleware

Temp function that I tried

    checkk = (req, res, next) => {

        console.log('middleware')
        res.redirect('api/auth/confirmation')
        next()
    }

auth/auth.js

    router.post('/confirmation', (req,res)=>{
        //do something
    })

/users.js

    router.post('/', auth.checkk, async (req, res) => {
        res.send("user route")
    })

Exptected Output

middleware
confirm route (If some error occurs it will go back with response)
user route

I dont want users to hit /auth/confirmation endpoint by themselves but via /users .

Edit

I am using express-validator to check req body, and I want the middleware to check that

router.post('/confirmation', [
    check('name', 'Name is required').not().isEmpty(),
    check('email', 'Enter valid email').isEmail(),

Answer 1

You wouldn't use a route as middleware but instead a function. A common flow for your auth scenario is:

1. User makes request to access secure route POST /users
2. A first piece of middleware will set a user context eg:

function setUserContext(req,res,next) {
    // get user from session or decode a JWT from auth header etc.
    if (user) {
        // user will be available for the lifetime of the request
        req.user = user
    }
    next()
}

Use this middleware across all routes: app.use(setUserContext)

3. A second middleware function can be applied to routes which need securing:

function requireLoggedInUser(req,res,next) {
    if (req.user) {
        return next()
    }
    throw new Error("You need to be logged in")
}

Apply to the users route: app.post('/users', requireLoggedInUser, (req, res) => { ... })

In this case you wouldn't have the confirmation route but instead two middleware functions.