Make two Duplex streamx streams that are passing through to each other.
Write to one, it push data to the other one.
npm install duplex-through
Useful for testing server/client flows
const duplexThrough = require('duplex-through')
const [a, b] = duplexThrough()
a.write('hello')
b.on('data', function (data) {
// hello
})
MIT