consume-filestream.js

var bufferjoiner = require('bufferjoiner')

/**
 * Consumes and buffers a file stream
 * @param  {ReadStream}   fileStream The readable file stream
 * @param  {Function}     callback   The done callback
 */

module.exports = function consumeFileStream(fileStream, callback) {
  if (undefined === callback) return consumeFileStream.bind(null, fileStream)

  var buffer = bufferjoiner()

  fileStream.on('data', function (data) {
    buffer.add(data)
  })

  fileStream.on('end', function () {
    callback(null, buffer.join())
  })
}

get-filestream.js

var parse = require('co-busboy')

/**
 * Retrieve a file stream from a koa request.
 * Supports multipart and binary uploads
 * @param {Context}         ctx  The koa context
 * @yield {ReadableStream}       The readable stream with incoming file
 */

module.exports = function *getFileStream(ctx) {
  var fileStream

  if (/image/.test(ctx.get('content-type'))) {
    fileStream = ctx.req
  } else {
    fileStream = yield parse(ctx, { autoFields: true })
  }

  return fileStream
}