Imagine you have the following setup for an Express app:
const express = require('express')
const app = express()
app.use((req, res, next) => {
console.log('\n\nALWAYS')
next()
})
app.get('/a', (req, res) => {
console.log('/a: route terminated')
res.send('/a')
})
app.use((req, res) => {
console.log('route not handled')
res.send('404 - not found')
})
app.listen(3000, () => {
console.log('listening on 3000')
})
If you were to visit /a, the console would show:
ALWAYS
/a: route terminated
ALWAYS
route not handled
It might be confusing to see an extra middleware log. You might have expected only two lines of console output like this:
ALWAYS
route not handled
Can someone explain why that additional middleware log showed up unexpectedly?