var peek = require('peek-stream')
var ldjson = require('ldjson-stream')
var csv = require('csv-parser')
var isCSV = function(data) {
  return data.toString().indexOf(',') > -1
}
var isJSON = function(data) {
  try {
    JSON.parse(data)
    return true
  } catch (err) {
    return false
  }
}
// call parser to create a new parser
var parser = function() {
  return peek(function(data, swap) {
    // maybe it is JSON?
    if (isJSON(data)) return swap(null, ldjson())
    // maybe it is CSV?
    if (isCSV(data)) return swap(null, csv())
    // we do not know - bail
    swap(new Error('No parser available'))
  })
}

var parse = parser()
parse.write('{"hello":"world"}\n{"hello":"another"}\n')
parse.on('data', function(data) {
  console.log(data) // prints {hello:'world'} and {hello:'another'}
})

var parse = parser()
parse.write('test,header\nvalue-1,value-2\n')
parse.on('data', function(data) {
  console.log(data) // prints {test:'value-1', header:'value-2'}
})

var parse = peek({
  maxBuffer: 10000
}, function(data, swap) {
  ...
})