index.js

const hyperdrive = require('hyperdrive')
const swarm = require('hyperdiscovery')
const ram = require('random-access-memory')

var a1 = hyperdrive(ram)
var a2
a1.ready(function () {
  swarm(a1)
  a1.writeFile('/foo', 'bar', done)
  a2 = hyperdrive(ram, a1.key)
  a2.ready(function () {
    swarm(a2)
    a2.metadata.on('download', (idx, data) => console.log('download', idx, data))
  })
})

function done () {
  a2.readFile('/foo', function (err, data) {
    if (err) console.log(err)

    console.log('file', data.toString()) // === 'bar'

    // after download completed, readdir returns the correct result
    a2.readdir('/', function (err, data) {
      if (err) console.log(err)

      console.log('dir', data) // === ['foo]
    })
  })

  a2.readdir('/', function (err, data) {
    // somehow this will not wait metadata to download before firing callback
    if (err) console.log(err)

    console.log('dir', data) // === []
  })
}

package.json

{
  "name": "hd8",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "hyperdiscovery": "^1.3.0",
    "hyperdrive": "^8.1.0",
    "random-access-memory": "^2.3.0"
  }
}