test.js

const fs = require('fs')
const os = require('os')
const path = require('path')
const { once } = require('events')
const test = require('brittle')
const Corestore = require('corestore')
const RAM = require('random-access-memory')
const { discoveryKey } = require('hypercore-crypto')
const { pipelinePromise: pipeline, Writable, Readable } = require('streamx')
const testnet = require('hyperdht/testnet')
const DHT = require('hyperdht')
const Hyperswarm = require('hyperswarm')
const b4a = require('b4a')

const Hyperdrive = require('./index.js')

test('drive.core', async (t) => {
  const { drive } = await testenv(t.teardown)
  t.is(drive.db.feed, drive.core)
})

test('drive.version', async (t) => {
  const { drive } = await testenv(t.teardown)
  await drive.put(__filename, fs.readFileSync(__filename))
  t.is(drive.db.feed.length, drive.version)
})

test('drive.key', async (t) => {
  const { drive } = await testenv(t.teardown)
  t.is(b4a.compare(drive.db.feed.key, drive.key), 0)
})

test('drive.discoveryKey', async (t) => {
  const { drive } = await testenv(t.teardown)
  t.is(b4a.compare(drive.discoveryKey, discoveryKey(drive.key)), 0)
})

test('drive.contentKey', async (t) => {
  const { drive } = await testenv(t.teardown)
  t.is(b4a.compare(drive.blobs.core.key, drive.contentKey), 0)
})

test('drive.getBlobs()', async (t) => {
  const { drive } = await testenv(t.teardown)
  const blobs = await drive.getBlobs()
  t.is(blobs, drive.blobs)
})

test('drive.supportsMetadata', async (t) => {
  const { drive } = await testenv(t.teardown)
  t.is(true, drive.supportsMetadata)
})

test('Hyperdrive(corestore, key)', async (t) => {
  t.plan(2)
  const { corestore, drive } = await testenv(t.teardown)
  const diskbuf = fs.readFileSync(__filename)
  await drive.put(__filename, diskbuf)
  const bndlbuf = await drive.get(__filename)
  t.is(b4a.compare(diskbuf, bndlbuf), 0)
  const mirror = new Hyperdrive(corestore.session({ writable: false }), drive.core.key)
  await mirror.ready()
  const mrrrbuf = await mirror.get(__filename)
  t.is(b4a.compare(bndlbuf, mrrrbuf), 0)
})

test('drive.put(path, buf) and drive.get(path)', async (t) => {
  {
    const { drive } = await testenv(t.teardown)
    const diskbuf = fs.readFileSync(__filename)
    await drive.put(__filename, diskbuf)
    const bndlbuf = await drive.get(__filename)
    t.is(b4a.compare(diskbuf, bndlbuf), 0)
  }

  {
    const { drive } = await testenv(t.teardown)
    const tmppath = path.join(os.tmpdir(), 'hyperdrive-test-')
    const dirpath = fs.mkdtempSync(tmppath)
    const filepath = path.join(dirpath, 'hello-world.js')
    const bndlbuf = b4a.from('module.exports = () => \'Hello, World!\'')
    await drive.put(filepath, bndlbuf)
    fs.writeFileSync(filepath, await drive.get(filepath))
    const diskbuf = fs.readFileSync(filepath)
    t.is(b4a.compare(diskbuf, bndlbuf), 0)
    t.is(require(filepath)(), 'Hello, World!')
  }
})

test('drive.get(path, { wait: false }) throws if entry exists but not found', async (t) => {
  const { drive, mirror } = await testenv(t.teardown)

  const otherDrive = mirror.drive
  const s1 = drive.corestore.replicate(true)
  const s2 = otherDrive.corestore.replicate(false)
  s1.pipe(s2).pipe(s1)

  await drive.put('/file', 'content')
  await eventFlush()

  await otherDrive.entry('/file') // Ensure in bee

  await t.exception(() => otherDrive.get('/file', { wait: false }), /BLOCK_NOT_AVAILABLE/)
  t.is(b4a.toString((await otherDrive.get('/file'))), 'content', 'sanity check: can actually get content')
})

test('drive.createWriteStream(path) and drive.createReadStream(path)', async (t) => {
  {
    const { drive } = await testenv(t.teardown)
    const diskbuf = await fs.readFileSync(__filename)
    await pipeline(
      fs.createReadStream(__filename),
      drive.createWriteStream(__filename)
    )
    let bndlbuf = null
    await pipeline(
      drive.createReadStream(__filename),
      new Writable({
        write (data, cb) {
          if (bndlbuf) bndlbuf = b4a.concat(bndlbuf, data)
          else bndlbuf = data
          return cb(null)
        }
      })
    )
    t.is(b4a.compare(diskbuf, bndlbuf), 0)
  }

  {
    const { drive } = await testenv(t.teardown)
    const tmppath = path.join(os.tmpdir(), 'hyperdrive-test-')
    const dirpath = fs.mkdtempSync(tmppath)
    const filepath = path.join(dirpath, 'hello-world.js')
    const bndlbuf = b4a.from('module.exports = () => \'Hello, World!\'')
    await pipeline(
      Readable.from(bndlbuf),
      drive.createWriteStream(filepath)
    )
    await pipeline(
      drive.createReadStream(filepath),
      fs.createWriteStream(filepath)
    )
    const diskbuf = fs.readFileSync(filepath)
    t.is(b4a.compare(diskbuf, bndlbuf), 0)
    t.is(require(filepath)(), 'Hello, World!')
  }
})

test('drive.createReadStream() with start/end options', async (t) => {
  const { drive, paths } = await testenv(t.teardown)
  const filepath = path.join(paths.tmp, 'hello-world.js')
  const bndlbuf = b4a.from('module.exports = () => \'Hello, World!\'')
  await pipeline(
    Readable.from(bndlbuf),
    drive.createWriteStream(filepath)
  )

  const stream = drive.createReadStream(filepath, {
    start: 0,
    end: 0
  })
  const drivebuf = await streamToBuffer(stream)
  t.is(drivebuf.length, 1)
  t.is(drivebuf.toString(), 'm')

  const stream2 = drive.createReadStream(filepath, {
    start: 5,
    end: 7
  })
  const drivebuf2 = await streamToBuffer(stream2)
  t.is(drivebuf2.length, 3)
  t.is(drivebuf2.toString(), 'e.e')
})

test('drive.del() deletes entry at path', async (t) => {
  t.plan(3)
  const { drive } = await testenv(t.teardown)
  await drive.put(__filename, fs.readFileSync(__filename))
  let buf = await drive.get(__filename)
  t.ok(b4a.isBuffer(buf))
  await drive.del(__filename)
  buf = await drive.get(__filename)
  t.is(buf, null)
  const entry = await drive.entry(__filename)
  t.is(entry, null)
})

test('drive.symlink(from, to) updates the entry at <from> to include a reference for <to>', async (t) => {
  const { drive } = await testenv(t.teardown)
  const buf = fs.readFileSync(__filename)
  await drive.put(__filename, buf)
  await drive.symlink('pointer', __filename)
  const result = await drive.get('pointer')
  t.is(result, null)
  const entry = await drive.entry('pointer')
  t.is(entry.value.linkname, __filename)
  t.is(b4a.compare(buf, await drive.get(entry.value.linkname)), 0)
})

test('drive.entry(path) gets entry at path', async (t) => {
  const linkname = 'linkname'

  {
    const { drive } = await testenv(t.teardown)
    const buf = fs.readFileSync(__filename)
    await drive.put(__filename, buf)
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, false)
  }

  {
    const { drive } = await testenv(t.teardown)
    const buf = fs.readFileSync(__filename)
    await drive.put(__filename, buf, { executable: false })
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, false)
  }

  {
    const { drive } = await testenv(t.teardown)
    const buf = fs.readFileSync(__filename)
    await drive.put(__filename, buf, { executable: true })
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, true)
  }

  {
    const { drive } = await testenv(t.teardown)
    const buf = fs.readFileSync(__filename)
    await drive.put(__filename, buf, { executable: false })
    await drive.symlink(__filename, linkname)
    const { value: entry } = await drive.entry(__filename)
    t.is(entry.blob, null)
    t.is(entry.executable, false)
    t.is(entry.linkname, linkname)
  }

  {
    const { drive } = await testenv(t.teardown)
    const buf = fs.readFileSync(__filename)
    await drive.put(__filename, buf, { executable: true })
    await drive.symlink(__filename, linkname)
    const { value: entry } = await drive.entry(__filename)
    t.is(entry.blob, null)
    t.is(entry.executable, false)
    t.is(entry.linkname, linkname)
  }

  {
    const { drive } = await testenv(t.teardown)
    await drive.symlink(linkname, __filename)
    const { value: entry } = await drive.entry(linkname)
    t.is(entry.blob, null)
    t.is(entry.executable, false)
    t.is(entry.linkname, __filename)
  }

  {
    const { drive } = await testenv(t.teardown)
    const ws = drive.createWriteStream(__filename)
    ws.write(fs.readFileSync(__filename))
    ws.end()
    await once(ws, 'finish')
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, false)
  }

  {
    const { drive } = await testenv(t.teardown)
    const ws = drive.createWriteStream(__filename, { executable: false })
    ws.write(fs.readFileSync(__filename))
    ws.end()
    await once(ws, 'finish')
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, false)
  }

  {
    const { drive } = await testenv(t.teardown)
    const ws = drive.createWriteStream(__filename, { executable: true })
    ws.write(fs.readFileSync(__filename))
    ws.end()
    await once(ws, 'finish')
    const { value: entry } = await drive.entry(__filename)
    t.ok(entry.blob)
    t.is(entry.linkname, null)
    t.is(entry.executable, true)
  }
})

test('entry(key) resolve key path', async function (t) {
  const { drive } = await testenv(t.teardown)

  await drive.put('/README.md', b4a.from('# title'))
  await drive.put('/examples/a.txt', b4a.from('a text'))
  await drive.put('/examples/more/c.txt', b4a.from('c text'))

  t.alike((await drive.entry('README.md')).key, '/README.md')
  t.alike((await drive.entry('/examples/more/../a.txt')).key, '/examples/a.txt')
  t.alike((await drive.entry('\\examples\\more\\c.txt')).key, '/examples/more/c.txt')
})

test('get(key) resolve key path', async function (t) {
  const { drive } = await testenv(t.teardown)

  await drive.put('/README.md', b4a.from('# title'))
  await drive.put('/examples/a.txt', b4a.from('a text'))
  await drive.put('/examples/more/c.txt', b4a.from('c text'))

  const buffer = await drive.get('/README.md')
  const a = await drive.get('/examples/a.txt')
  const c = await drive.get('/examples/more/c.txt')
  t.ok(buffer)
  t.ok(a)
  t.ok(c)

  t.alike(await drive.get('README.md'), buffer)
  t.alike(await drive.get('/examples/more/../a.txt'), a)
  t.alike(await drive.get('\\examples\\more\\c.txt'), c)
})

test('entry(key) resolves object', async function (t) {
  const { drive } = await testenv(t.teardown)

  await drive.put('/README.md', b4a.from('# title'))

  const entry = await drive.entry('/README.md')
  t.alike(entry, await drive.entry(entry))
})

test('del(key) resolve key path', async function (t) {
  const { drive } = await testenv(t.teardown)

  const delAndEntry = async (key, expectedKey) => {
    await drive.put(expectedKey, b4a.from('')) // pre-create

    t.ok(await drive.entry(expectedKey))
    await drive.del(key)
    t.absent(await drive.entry(expectedKey))
  }

  await delAndEntry('README.md', '/README.md')
  await delAndEntry('/examples/more/../a.txt', '/examples/a.txt')
  await delAndEntry('\\examples\\more\\c.txt', '/examples/more/c.txt')
})

test('put(key, buffer) resolve key path', async function (t) {
  const { drive } = await testenv(t.teardown)

  const putAndEntry = async (key, expectedKey) => {
    t.absent(await drive.entry(expectedKey))
    await drive.put(key, b4a.from(''))
    t.ok(await drive.entry(expectedKey))
  }

  await putAndEntry('b.txt', '/b.txt')
  await putAndEntry('/examples/more/../f.txt', '/examples/f.txt')
  await putAndEntry('\\examples\\more\\h.txt', '/examples/more/h.txt')
})

test('symlink(key, linkname) resolve key path', async function (t) {
  const { drive } = await testenv(t.teardown)

  await drive.put('/README.md', b4a.from('# title'))

  const symlinkAndEntry = async (key, expectedKey) => {
    t.absent(await drive.entry(expectedKey))
    await drive.symlink(key, '/README.md')
    t.ok(await drive.entry(expectedKey))
  }

  await symlinkAndEntry('b.txt', '/b.txt')
  await symlinkAndEntry('/examples/more/../f.txt', '/examples/f.txt')
  await symlinkAndEntry('\\examples\\more\\h.txt', '/examples/more/h.txt')
})

test('watch() basic', async function (t) {
  t.plan(5)

  const { drive } = await testenv(t.teardown)
  const buf = b4a.from('hi')

  const watcher = drive.watch()

  eventFlush().then(async () => {
    await drive.put('/a.txt', buf)
  })

  for await (const [current, previous] of watcher) { // eslint-disable-line no-unreachable-loop
    t.ok(current instanceof Hyperdrive)
    t.ok(previous instanceof Hyperdrive)
    t.is(current.version, 2)
    t.is(previous.version, 1)
    t.alike(await current.get('/a.txt'), buf)
    break
  }
})

test('watch(folder) basic', async function (t) {
  t.plan(1)

  const { drive } = await testenv(t.teardown)
  const buf = b4a.from('hi')

  await drive.put('/README.md', buf)
  await drive.put('/examples/a.txt', buf)
  await drive.put('/examples/more/a.txt', buf)

  const watcher = drive.watch('/examples')

  let next = watcher.next()
  let onchange = null
  next.then(data => {
    next = watcher.next()
    onchange(data)
  })

  onchange = () => t.fail('should not trigger changes')
  await drive.put('/b.txt', buf)
  await eventFlush()
  onchange = null

  onchange = () => t.pass('change')
  await drive.put('/examples/b.txt', buf)
  await eventFlush()
  onchange = null
})

test('watch(folder) should normalize folder', async function (t) {
  t.plan(1)

  const { drive } = await testenv(t.teardown)
  const buf = b4a.from('hi')

  const watcher = drive.watch('examples//more//')

  let next = watcher.next()
  let onchange = null
  next.then(data => {
    next = watcher.next()
    onchange(data)
  })

  onchange = () => t.fail('should not trigger changes')
  await drive.put('/examples/a.txt', buf)
  await eventFlush()
  onchange = null

  onchange = () => t.pass('change')
  await drive.put('/examples/more/a.txt', buf)
  await eventFlush()
  onchange = null
})

test('drive.diff(length)', async (t) => {
  const { drive, paths: { root, tmp } } = await testenv(t.teardown)
  const paths = []

  for await (const _path of readdirator(root, { filter })) {
    const buf = fs.readFileSync(_path)
    const relpath = _path.replace(root, '')
    const tmppath = path.join(tmp, relpath)
    try {
      fs.writeFileSync(tmppath, buf)
    } catch {
      fs.mkdirSync(path.dirname(tmppath), { recursive: true })
      fs.writeFileSync(tmppath, buf)
    }
    await drive.put(relpath, buf)
    paths.push([tmppath, relpath])
  }

  const [tmppath, relpath] = paths[Math.floor(Math.random() * paths.length)]
  await drive.put(relpath + '.old', fs.readFileSync(tmppath))
  await drive.del(relpath)

  for await (const diff of drive.diff(drive.core.length - 2)) {
    if (diff.right) t.is(diff.right.key, relpath.replace(/\\/g, '/'))
    if (diff.left) t.is(diff.left.key, relpath.replace(/\\/g, '/') + '.old')
  }
})

test('drive.entries()', async (t) => {
  const { drive, paths: { root } } = await testenv(t.teardown)
  const entries = new Set()

  for await (const path of readdirator(root, { filter })) {
    await drive.put(path, fs.readFileSync(path))
    entries.add(await drive.entry(path))
  }

  for await (const entry of drive.entries()) {
    for (const _entry of entries) {
      if (JSON.stringify(_entry) === JSON.stringify(entry)) {
        entries.delete(_entry)
        break
      }
    }
  }

  t.is(entries.size, 0)
})

test('drive.entries() with explicit range, no opts', async (t) => {
  const { drive } = await testenv(t.teardown)

  await drive.put('/aFile', 'here')
  await drive.put('/bFile', 'later')
  await drive.put('/zFile', 'last')

  const expected = ['/bFile', '/zFile']
  const observed = []
  for await (const entry of drive.entries({ gt: '/b', lte: '/zzz' })) {
    observed.push(entry.key)
  }

  t.alike(expected, expected)
})

test('drive.entries() with explicit range and opts', async (t) => {
  const { drive } = await testenv(t.teardown)

  await drive.put('/aFile', 'here')
  await drive.put('/bFile', 'later')
  await drive.put('/zFile', 'last')

  const expected = ['/zFile', '/bFile']
  const observed = []
  for await (const entry of drive.entries({ gt: '/b', lte: '/zzz' }, { reverse: true })) {
    observed.push(entry.key)
  }

  t.alike(observed, expected)
})

test('drive.list(folder, { recursive })', async (t) => {
  {
    const { drive, paths: { root } } = await testenv(t.teardown)
    for await (const path of readdirator(root, { filter })) {
      await drive.put(path, fs.readFileSync(path))
    }
    for await (const entry of drive.list(root)) {
      t.is(b4a.compare(fs.readFileSync(entry.key), await drive.get(entry.key)), 0)
    }
  }

  {
    const { drive, paths: { root } } = await testenv(t.teardown)
    for await (const path of readdirator(root, { filter })) {
      await drive.put(path, fs.readFileSync(path))
    }
    for await (const entry of drive.list(root, { recursive: true })) {
      t.is(b4a.compare(fs.readFileSync(entry.key), await drive.get(entry.key)), 0)
    }
  }

  {
    const { drive, paths: { root } } = await testenv(t.teardown)
    for await (const path of readdirator(root, { filter })) {
      await drive.put(path, fs.readFileSync(path))
    }
    for await (const entry of drive.list(root, { recursive: false })) {
      t.is(b4a.compare(fs.readFileSync(entry.key), await drive.get(entry.key)), 0)
    }
  }

  {
    const { drive } = await testenv(t.teardown)
    const emptybuf = b4a.from('')
    await drive.put('/grandparent', emptybuf)
    await drive.put('/grandparent/parent', emptybuf)
    await drive.put('/grandparent/parent/child', emptybuf)
    await drive.put('/grandparent/parent/child/fst-grandchild.file', emptybuf)
    await drive.put('/grandparent/parent/child/snd-grandchild.file', emptybuf)

    const paths = ['/grandparent', '/grandparent/parent', '/grandparent/parent/child']

    for (const [_idx, path] of Object.entries(paths)) {
      const idx = parseInt(_idx)
      const set = new Set()
      for await (const entry of drive.list(path)) set.add(entry.key)
      t.ok(paths.slice(0, idx).every((path) => !set.has(path)))
      t.ok(paths.slice(idx, paths.length).every((path) => Array.from(set).some((_path) => _path.includes(path))))
    }
  }
})

test('drive.readdir(path)', async (t) => {
  {
    const { drive, paths: { root } } = await testenv(t.teardown)
    const files = new Map()
    for await (const path of readdirator(root, { filter })) {
      const buf = fs.readFileSync(path)
      await drive.put(path, buf)
      files.set(path, buf)
    }
    const readdir = drive.readdir.bind(drive)
    const isDirectory = async (x) => !(await drive.entry(x))?.value.blob
    for await (const path of readdirator(root, { readdir, isDirectory })) {
      t.is(b4a.compare(files.get(path), await drive.get(path)), 0)
    }
  }

  {
    const { drive } = await testenv(t.teardown)
    await drive.put('/parent/child', b4a.from('child'))
    await drive.put('/parent/sibling', b4a.from('sibling'))
    await drive.put('/parent/sibling/grandchild', b4a.from('grandchild'))
    const read = []
    for await (const path of drive.readdir('/parent')) read.push(path)
    t.is(read[0], 'child')
    t.is(read[1], 'sibling')
    t.is(read.length, 2)
  }

  {
    const { drive } = await testenv(t.teardown)
    await drive.put('/parent/child', b4a.from('child'))
    await drive.put('/parent/sibling', b4a.from('sibling'))
    await drive.put('/parent/sibling/grandchild', b4a.from('grandchild'))
    const read = []
    for await (const path of drive.readdir('/parent/sibling')) read.push(path)
    t.is(read[0], 'grandchild')
    t.is(read.length, 1)
  }
})

test('drive.checkout(len)', async (t) => {
  const { drive, paths: { root } } = await testenv(t.teardown)
  const lens = new Map()
  for await (const path of readdirator(root, { filter })) {
    const buf = fs.readFileSync(path)
    await drive.put(path, buf)
    lens.set(drive.core.length, path)
  }
  for (const offset of lens.keys()) {
    const snapshot = await drive.checkout(offset)
    t.ok(snapshot.get(lens.get(offset)))
    let low = offset
    while (lens.has(--low)) t.ok(await snapshot.get(lens.get(low)))
    let high = offset
    while (lens.has(++high)) t.ok(!(await snapshot.get(lens.get(high))))
  }
})

test('drive.download(folder, [options])', async (t) => {
  t.plan(7)
  const { corestore, drive, swarm, mirror } = await testenv(t.teardown)
  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()

  const nil = b4a.from('nil')

  let count = 0
  let max = -Infinity

  await drive.put('/parent/child/grandchild1', nil)
  await drive.put('/parent/child/grandchild2', nil)

  const blobs = await mirror.drive.getBlobs()

  blobs.core.on('download', (offset) => {
    count++
    if (max < offset) max = offset
  })

  const l = drive.blobs.core.length

  await drive.put('/parent/sibling/grandchild1', nil)

  t.is(count, 0)
  await mirror.drive.download('/parent/child')
  t.is(max, l - 1)
  const _count = count
  t.ok(await mirror.drive.get('/parent/child/grandchild1'))
  t.is(_count, count)
  t.ok(await mirror.drive.get('/parent/child/grandchild2'))
  t.is(_count, count)
  const entry = await mirror.drive.entry('/parent/sibling/grandchild1')
  await blobs.get(entry.value.blob)
  t.is(count, _count + 1)
})

test('drive.download(filename, [options])', async (t) => {
  const { corestore, drive, swarm, mirror } = await testenv(t.teardown)
  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()

  const nil = b4a.from('nil')

  await drive.put('/parent/grandchild1', nil)
  await drive.put('/file', nil)
  await drive.put('/parent/grandchild2', nil)

  await mirror.drive.getBlobs()

  await mirror.drive.download('/file')

  t.ok(await mirror.drive.get('/file', { wait: false }))

  try {
    await mirror.drive.get('/file1', { wait: false })
  } catch {
    t.pass('not downloaded')
  }
})

test.skip('drive.downloadRange(dbRanges, blobRanges)', async (t) => {
  const { drive, swarm, mirror, corestore } = await testenv(t.teardown)
  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()

  const blobs = await drive.getBlobs()
  const nil = b4a.from('nil')

  const fileBlocks = []
  const blobBlocks = []
  await drive.put('/0', nil)
  fileBlocks.push(drive.core.length)
  blobBlocks.push(blobs.core.length)
  await drive.put('/1', nil)
  await drive.put('/2', nil)
  fileBlocks.push(drive.core.length)
  blobBlocks.push(blobs.core.length)

  const fileTelem = downloadShark(mirror.drive.core)
  const blobTelem = downloadShark((await mirror.drive.getBlobs()).core)

  const fileCount = fileTelem.count
  const blobCount = blobTelem.count

  await mirror.drive.get('/0')
  t.is(blobCount, blobTelem.count)
  t.is(fileCount, fileTelem.count)
})

test.skip('drive.downloadDiff(version, folder, [options])', async (t) => {
  const { drive, swarm, mirror, corestore } = await testenv(t.teardown)
  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()

  const nil = b4a.from('nil')

  await drive.put('/parent/child/0', nil)
  await drive.put('/parent/sibling/0')
  await drive.put('/parent/child/1', nil)
  const version = drive.version

  const filestelem = downloadShark(mirror.drive.core)
  const blobstelem = downloadShark((await mirror.drive.getBlobs()).core)

  await mirror.drive.downloadDiff(version, '/parent/child')

  let filescount = filestelem.count
  let blobscount = blobstelem.count

  await mirror.drive.get('/parent/child/1')

  t.is(filescount, filestelem.count)
  t.is(blobscount, blobstelem.count)

  await drive.put('/parent/child/2', nil)

  await mirror.drive.downloadDiff(version, '/parent/child')

  t.is(blobscount + 1, blobstelem.count)

  filescount = filestelem.count
  blobscount = blobstelem.count

  await mirror.drive.get('/parent/sibling/0')

  t.is(filescount + 1, filestelem.count)
  t.is(blobscount + 1, blobstelem.count)
})

test('drive.batch() & drive.flush()', async (t) => {
  const { drive } = await testenv(t.teardown)

  const batch = drive.batch()

  await batch.put('/file.txt', b4a.from('abc'))
  t.absent(await drive.get('/file.txt'))

  await batch.flush()
  t.ok(batch.blobs.core.closed)
  t.absent(drive.blobs.core.closed)
  t.absent(drive.db.closed)
  t.absent(drive.db.core.closed)

  t.ok(await drive.get('/file.txt'))

  await drive.close()
  t.ok(drive.blobs.core.closed)
  t.ok(drive.db.closed)
  t.ok(drive.db.core.closed)
})

test('batch.list()', async (t) => {
  t.plan(1)
  const { drive } = await testenv(t.teardown)
  const nil = b4a.from('nil')
  await drive.put('/x', nil)
  const batch = drive.batch()
  for await (const entry of batch.list()) {
    t.is(entry.key, '/x')
  }
  await batch.flush()
})

test('drive.close()', async (t) => {
  t.plan(2)
  const { drive } = await testenv(t.teardown)
  const blobs = await drive.getBlobs()
  blobs.core.on('close', () => t.ok(true))
  drive.core.on('close', () => t.ok(true))
  await drive.close()
})

test('drive.close() on snapshots--does not close parent', async (t) => {
  const { drive } = await testenv(t.teardown)

  await drive.put('/foo', b4a.from('bar'))

  const checkout = drive.checkout(2)
  await checkout.get('/foo')
  await checkout.close()

  // Main test is that there is no session_closed error on drive.get
  const res = await drive.get('/foo')
  t.alike(res, b4a.from('bar'))
})

test('drive.batch() on non-ready drive', async (t) => {
  const drive = new Hyperdrive(new Corestore(RAM))

  const batch = drive.batch()
  await batch.put('/x', 'something')

  await batch.flush()
  t.is(batch.blobs.core.closed, true)

  t.ok(await drive.get('/x'))
})

test('drive.close() for future checkout', async (t) => {
  const { drive } = await testenv(t.teardown)
  await drive.put('some', 'thing')
  const checkout = drive.checkout(drive.length + 1)
  await checkout.close()

  t.is(checkout.closed, true)
  t.is(checkout.db.core.closed, true)
  t.is(drive.closed, false)
  t.is(drive.db.core.closed, false)
})

test('drive.close() with openBlobsFromHeader waiting in the background', async (t) => {
  t.plan(3)

  const corestore = new Corestore(RAM)
  const disconnectedCoreKey = b4a.from('a'.repeat(64), 'hex')
  const drive = new Hyperdrive(corestore, disconnectedCoreKey)

  await drive.ready()
  t.is(drive.core.length, 0) // Sanity check
  // length 0 (unavailable), so _openBlobsFromHeader will be awaiting its header

  // Testing against a regression where close silently errored and never finished
  drive.core.on('close', () => t.ok(true))
  await drive.close()

  t.ok(drive.corestore.closed)
})

test.skip('drive.findingPeers()', async (t) => {
  const { drive, corestore, swarm, mirror } = await testenv(t.teardown)
  await drive.put('/', b4a.from('/'))

  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  const done = mirror.drive.findingPeers()
  swarm.flush().then(done, done)
  t.ok(await mirror.drive.get('/'))
})

test('drive.mirror()', async (t) => {
  const { drive: a } = await testenv(t.teardown)
  const { drive: b } = await testenv(t.teardown)

  await a.put('/file.txt', 'hello world')
  await a.mirror(b).done()

  t.alike(await b.get('/file.txt'), b4a.from('hello world'))
})

test('blobs with writable drive', async (t) => {
  t.plan(4)

  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  drive.on('blobs', function (blobs) {
    t.is(blobs, drive.blobs)
  })

  drive.on('content-key', function (key) {
    t.alike(key, drive.blobs.core.key)
  })

  t.absent(drive.blobs)
  await drive.ready()
  t.ok(drive.blobs)
})

test('drive.clear(path)', async (t) => {
  const { drive } = await testenv(t.teardown)
  await drive.put('/loc', 'hello world')

  const entry = await drive.entry('/loc')
  const initContent = await drive.blobs.get(entry.value.blob, { wait: false })
  t.alike(initContent, b4a.from('hello world'))

  const cleared = await drive.clear('/loc')
  t.is(cleared, null)

  // Entry still exists (so file not deleted)
  const nowEntry = await drive.entry('/loc')
  t.alike(nowEntry, entry)

  // But the blob is removed from storage
  const nowContent = await drive.blobs.get(entry.value.blob, { wait: false })
  t.is(nowContent, null)
})

test('drive.clear(path) with diff', async (t) => {
  const storage = createTmpDir(t)

  const a = new Hyperdrive(new Corestore(storage))
  await a.put('/file', b4a.alloc(4 * 1024))
  await a.close()

  const b = new Hyperdrive(new Corestore(storage))

  const cleared = await b.clear('/file', { diff: true })
  t.ok(cleared.blocks > 0)

  const cleared2 = await b.clear('/file', { diff: true })
  t.is(cleared2.blocks, 0)

  const cleared3 = await b.clear('/not-exists', { diff: true })
  t.is(cleared3.blocks, 0)

  await b.close()
})

test('drive.clear(path) on a checkout', async (t) => {
  const { drive } = await testenv(t.teardown)
  await drive.put('/loc', 'hello world')

  const entry = await drive.entry('/loc')
  const initContent = await drive.blobs.get(entry.value.blob, { wait: false })
  t.alike(initContent, b4a.from('hello world'))

  const checkout = drive.checkout(drive.version)

  const cleared = await checkout.clear('/loc')
  t.is(cleared, null)

  // Entry still exists (so file not deleted)
  const nowEntry = await checkout.entry('/loc')
  t.alike(nowEntry, entry)

  // But the blob is removed from storage
  const nowContent = await checkout.blobs.get(entry.value.blob, { wait: false })
  t.is(nowContent, null)
})

test('drive.clearAll() with diff', async (t) => {
  const storage = createTmpDir(t)

  const a = new Hyperdrive(new Corestore(storage))
  await a.put('/file-1', b4a.alloc(4 * 1024))
  await a.put('/file-2', b4a.alloc(8 * 1024))
  await a.put('/file-3', b4a.alloc(16 * 1024))
  await a.close()

  const b = new Hyperdrive(new Corestore(storage))

  const cleared = await b.clearAll({ diff: true })
  t.ok(cleared.blocks > 0)

  const cleared2 = await b.clearAll({ diff: true })
  t.is(cleared2.blocks, 0)

  const cleared3 = await b.clearAll()
  t.is(cleared3, null)

  await b.close()
})

test('drive.purge()', async (t) => {
  const storage = createTmpDir(t)
  const store = new Corestore(storage)

  const a = new Hyperdrive(store)
  await a.put('/file', 'I am content')

  const coresDir = path.join(storage, 'cores')
  t.ok(fs.existsSync(coresDir))

  await a.purge()
  t.absent(fs.existsSync(coresDir))
  t.ok(a.closed)
})

test('entry(key) cancelled when checkout closes', async function (t) {
  const { drive } = await testenv(t.teardown)
  await drive.put('some', '1')

  const snap = drive.checkout(3) // Future
  const prom = snap.entry('some')

  const [a, b] = await Promise.allSettled([snap.close(), prom])

  t.is(a.status, 'fulfilled')
  t.is(b.status, 'rejected')
})

test('drive.exists(key)', async function (t) {
  const { drive } = await testenv(t.teardown)

  t.is(await drive.exists('/file'), false)

  await drive.put('/file', 'hi')
  t.is(await drive.exists('/file'), true)

  await drive.clear('/file')
  t.is(await drive.exists('/file'), true)

  await drive.del('/file')
  t.is(await drive.exists('/file'), false)
})

test('basic properties', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  t.is(typeof drive.findingPeers, 'function')
  t.is(typeof drive.replicate, 'function')

  t.is(drive.id, null)
  t.is(drive.key, null)
  t.is(drive.discoveryKey, null)

  t.is(drive.writable, false)
  t.is(drive.readable, true)

  await drive.ready()

  t.is(drive.writable, true)

  t.is(drive.id.length, 52)
  t.is(drive.key.byteLength, 32)
  t.is(drive.discoveryKey.byteLength, 32)

  t.is(drive.id, drive.core.id)
  t.is(drive.key, drive.core.key)
  t.is(drive.discoveryKey, drive.core.discoveryKey)
})

test('basic writable option', async function (t) {
  t.plan(3)

  const store = new Corestore(RAM)

  const a = new Hyperdrive(store)
  await a.put('/file-one', 'hi')

  const b = new Hyperdrive(store.session({ writable: false }), a.key)
  await b.ready()
  t.is(b.writable, false)
  t.is(b.blobs.core.writable, false)

  try {
    await b.put('/file-two', 'hi')
    t.fail('Should have failed')
  } catch (err) {
    t.is(err.code, 'SESSION_NOT_WRITABLE')
  }
})

test('readdir filenames with dashes', async function (t) {
  t.plan(2)

  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/one', 'hi')
  await drive.put('/one-two', 'hi')

  const expected = ['one', 'one-two']

  for await (const name of drive.readdir('/')) {
    t.is(name, expected.shift())
  }

  await drive.close()
})

test('readdir filenames with dashes (nested)', async function (t) {
  t.plan(2)

  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/one/two', 'hi')
  await drive.put('/one-two', 'hi')

  const expected = ['one-two', 'one']

  for await (const name of drive.readdir('/')) {
    t.is(name, expected.shift())
  }

  await drive.close()
})

test('basic compare', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/file.txt', 'hi')
  const a = await drive.entry('/file.txt')

  await drive.put('/file.txt', 'hi')
  const b = await drive.entry('/file.txt')

  await drive.put('/file.txt', 'hi')
  const c = await drive.entry('/file.txt')

  t.is(drive.compare(a, c), -1)
  t.is(drive.compare(a, b), -1)
  t.is(drive.compare(a, a), 0)
  t.is(drive.compare(c, c), 0)
  t.is(drive.compare(b, a), 1)
  t.is(drive.compare(c, a), 1)
})

test('basic follow entry', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/file.txt', 'hi')
  await drive.symlink('/file.shortcut', '/file.txt')

  t.is((await drive.entry('/file.shortcut')).value.linkname, '/file.txt')

  t.alike(await drive.entry('/file.shortcut', { follow: true }), {
    seq: 1,
    key: '/file.txt',
    value: {
      executable: false,
      linkname: null,
      blob: { byteOffset: 0, blockOffset: 0, blockLength: 1, byteLength: 2 },
      metadata: null
    }
  })

  await drive.close()
})

test('multiple follow entry', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/file.txt', 'hi')
  await drive.symlink('/file.shortcut', '/file.txt')
  await drive.symlink('/file.shortcut.shortcut', '/file.shortcut')

  t.is((await drive.entry('/file.shortcut.shortcut')).value.linkname, '/file.shortcut')

  t.alike(await drive.entry('/file.shortcut.shortcut', { follow: true }), {
    seq: 1,
    key: '/file.txt',
    value: {
      executable: false,
      linkname: null,
      blob: { byteOffset: 0, blockOffset: 0, blockLength: 1, byteLength: 2 },
      metadata: null
    }
  })

  await drive.close()
})

test('max follow entry', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/file.0.txt', 'hi')

  for (let i = 1; i <= 17; i++) {
    await drive.symlink('/file.' + i + '.txt', '/file.' + (i - 1) + '.txt')
  }

  t.is((await drive.entry('/file.0.txt')).value.linkname, null)
  t.is((await drive.entry('/file.1.txt')).value.linkname, '/file.0.txt')
  t.is((await drive.entry('/file.16.txt')).value.linkname, '/file.15.txt')

  try {
    await drive.entry('/file.16.txt', { follow: true })
    t.fail('Should have failed')
  } catch {
    t.pass()
  }

  await drive.close()
})

test('non-existing follow entry', async function (t) {
  const store = new Corestore(RAM)
  const drive = new Hyperdrive(store)

  await drive.put('/file.txt', 'hi')

  t.is(await drive.entry('/file.random.shortcut', { follow: true }), null)

  await drive.close()
})

test('drive.entry(key, { timeout })', async (t) => {
  t.plan(1)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  await swarm.destroy()
  await drive.close()

  try {
    await mirror.drive.entry('/file.txt', { timeout: 1 })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'REQUEST_TIMEOUT')
  }
})

test('drive.entry(key, { wait })', async (t) => {
  t.plan(1)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  await swarm.destroy()
  await drive.close()

  try {
    await mirror.drive.entry('/file.txt', { wait: false })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'BLOCK_NOT_AVAILABLE')
  }
})

test('drive.get(key, { timeout })', async (t) => {
  t.plan(3)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  const entry = await mirror.drive.entry('/file.txt')
  t.ok(entry)
  t.ok(entry.value.blob)

  await swarm.destroy()
  await drive.close()

  try {
    await mirror.drive.get('/file.txt', { timeout: 1 })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'REQUEST_TIMEOUT')
  }
})

test('drive.get(key, { wait }) with entry but no blob', async (t) => {
  t.plan(3)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  const entry = await mirror.drive.entry('/file.txt')
  t.ok(entry)
  t.ok(entry.value.blob)

  await swarm.destroy()
  await drive.close()

  try {
    await mirror.drive.get('/file.txt', { wait: false })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'BLOCK_NOT_AVAILABLE')
  }
})

test('drive.get(key, { wait }) without entry', async (t) => {
  t.plan(1)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  await swarm.destroy()
  await drive.close()

  try {
    await mirror.drive.get('/file.txt', { wait: false })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'BLOCK_NOT_AVAILABLE')
  }
})

test('drive peek with get() and timeout', async (t) => {
  t.plan(3)

  const { drive, swarm, mirror } = await testenv(t.teardown)
  await replicate(drive, swarm, mirror)

  await drive.put('/file.txt', b4a.from('hi'))
  await mirror.drive.getBlobs()

  const entry = await mirror.drive.entry('/file.txt')
  t.ok(entry)
  t.ok(entry.value.blob)

  try {
    await mirror.drive.get('/file.txt', { start: 100, timeout: 1 })
    t.fail('should have failed')
  } catch (error) {
    t.is(error.code, 'REQUEST_TIMEOUT')
  }
})

test('non-compat making of cores', async (t) => {
  const corestore = new Corestore(RAM)
  const drive = new Hyperdrive(corestore, { compat: false })

  await drive.ready()

  t.absent(drive.core.core.compat)
  t.absent(drive.blobs.core.core.compat)
})

test('getBlobsLength happy paths', async t => {
  const corestore = new Corestore(RAM.reusable())
  const drive = new Hyperdrive(corestore.session())

  await drive.put('./file', 'here')
  t.is(await drive.getBlobsLength(), 1, 'Correct blobs length 1')

  await drive.put('./file', 'here')
  t.is(await drive.getBlobsLength(), 2, 'Correct blobs length 2')

  t.is(drive.version, 3, 'sanity check')
  t.is(await drive.getBlobsLength(2), 1, 'Correct blobs length on explicit checkout')
  t.is(await drive.getBlobsLength(3), 2, 'Correct blobs length on explicit checkout to latest')
})

test('getBlobsLength when not ready', async t => {
  const corestore = new Corestore(RAM.reusable())
  {
    const drive = new Hyperdrive(corestore.session())
    await drive.put('./file', 'here')
    await drive.put('./more', 'here')
    await drive.close()
  }

  {
    const drive = new Hyperdrive(corestore)
    const length = await drive.getBlobsLength()
    t.is(length, 2, 'correct blobs length')
    await drive.close()
  }
})

test('getBlobsLength of empty drive', async t => {
  const corestore = new Corestore(RAM.reusable())
  const drive = new Hyperdrive(corestore.session())
  const length = await drive.getBlobsLength()
  t.is(length, 0, 'empty drive has blobsLength 0')
})

test('truncate happy path', async t => {
  const corestore = new Corestore(RAM.reusable())
  const drive = new Hyperdrive(corestore.session())
  await drive.ready()

  t.is(drive.db.core.fork, 0, 'sanity check')
  t.is(drive.blobs.core.fork, 0, 'sanity check')

  await drive.put('file1', 'here1')
  await drive.put('file2', 'here2')
  await drive.put('file3', 'here3')

  t.is(drive.version, 4, 'sanity check')
  t.is(await drive.getBlobsLength(), 3, 'sanity check')

  await drive.truncate(3)
  t.is(drive.version, 3, 'truncated db correctly')
  t.is(await drive.getBlobsLength(), 2, 'truncated blobs correctly')

  await drive.put('file3', 'here file 3 post truncation')
  t.is(drive.version, 4, 'correct version when putting after truncate')
  t.is(await drive.getBlobsLength(), 3, 'correct blobsLength when putting after truncate')
  t.is(
    b4a.toString(await drive.get('file3')),
    'here file 3 post truncation',
    'Sanity check'
  )

  t.is(drive.db.core.fork, 1, 'sanity check on db fork')
  t.is(drive.blobs.core.fork, 1, 'sanity check on blobs fork')
})

test('truncate throws when truncating future version)', async t => {
  const corestore = new Corestore(RAM.reusable())
  const drive = new Hyperdrive(corestore)

  await drive.put('./file', 'here')
  await t.exception(
    () => drive.truncate(10),
    /Bad truncation length/,
    'throws when truncating the future'
  )
})

test('get drive key without using the constructor', async (t) => {
  t.plan(1)
  const corestore = new Corestore(RAM.reusable())
  const key = await Hyperdrive.getDriveKey(corestore.session())
  const drive = new Hyperdrive(corestore.session())

  t.teardown(() => {
    corestore.close()
    drive.close()
  })

  await drive.ready()

  t.is(key.toString('hex'), drive.key.toString('hex'))
})

test('drive.list ignore', async (t) => {
  const { drive } = await testenv(t.teardown)

  await drive.put('/file_A', b4a.alloc(0))
  await drive.put('/file_B', b4a.alloc(0))

  await drive.put('/folder_A/file_A', b4a.alloc(0))
  await drive.put('/folder_A/file_B', b4a.alloc(0))
  await drive.put('/folder_B/file_A', b4a.alloc(0))
  await drive.put('/folder_B/file_B', b4a.alloc(0))

  await drive.put('/folder_A/subfolder_A/file_A', b4a.alloc(0))
  await drive.put('/folder_A/subfolder_A/file_B', b4a.alloc(0))
  await drive.put('/folder_A/subfolder_B/file_A', b4a.alloc(0))
  await drive.put('/folder_A/subfolder_B/file_B', b4a.alloc(0))
  await drive.put('/folder_B/subfolder_A/file_A', b4a.alloc(0))
  await drive.put('/folder_B/subfolder_A/file_B', b4a.alloc(0))
  await drive.put('/folder_B/subfolder_B/file_A', b4a.alloc(0))
  await drive.put('/folder_B/subfolder_B/file_B', b4a.alloc(0))

  const ignore = ['file_A',
    'folder_A',
    'folder_B/file_A',
    'folder_B/subfolder_A',
    'folder_B/subfolder_B/file_A'
  ]

  const expectedEntries = ['/file_B',
    '/folder_B/file_B',
    '/folder_B/subfolder_B/file_B'
  ]

  const entries = []
  for await (const entry of drive.list({ ignore })) {
    entries.push(entry.key)
  }

  t.alike(entries, expectedEntries)
})

test('drive.list (recursive false) ignore', async (t) => {
  const { drive } = await testenv(t.teardown)

  await drive.put('/file_A', b4a.alloc(0))
  await drive.put('/file_B', b4a.alloc(0))
  await drive.put('/folder_A/file_A', b4a.alloc(0))
  await drive.put('/folder_A/subfolder_A/file_A', b4a.alloc(0))

  const ignore = ['file_A', 'folder_A']
  const expectedEntries = [
    '/file_B'
  ]

  const entries = []
  for await (const entry of drive.list({ ignore, recursive: false })) {
    entries.push(entry.key)
  }

  t.alike(entries, expectedEntries)
})

test('upload/download can be monitored', async (t) => {
  t.plan(27)
  const { corestore, drive, swarm, mirror } = await testenv(t.teardown)
  swarm.on('connection', (conn) => corestore.replicate(conn))
  swarm.join(drive.discoveryKey, { server: true, client: false })
  await swarm.flush()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()

  const file = '/example.md'
  const bytes = 1024 * 100 // big enough to trigger more than one update event
  const buffer = Buffer.alloc(bytes, '0')
  await drive.put(file, buffer)

  {
    // Start monitoring upload
    const monitor = drive.monitor(file)
    await monitor.ready()
    t.is(monitor.name, file)
    const expectedBlocks = [2, 1]
    const expectedBytes = [bytes, 65536]
    monitor.on('update', () => {
      t.is(monitor.uploadStats.blocks, expectedBlocks.pop())
      t.is(monitor.uploadStats.monitoringBytes, expectedBytes.pop())
      t.is(monitor.uploadStats.targetBlocks, 2)
      t.is(monitor.uploadStats.targetBytes, bytes)
      t.is(monitor.uploadSpeed(), monitor.uploadStats.speed)
      if (!expectedBlocks.length) t.is(monitor.uploadStats.percentage, 100)
      t.absent(monitor.downloadStats.blocks)
    })
  }

  {
    // Start monitoring download
    const monitor = mirror.drive.monitor(file)
    await monitor.ready()
    const expectedBlocks = [2, 1]
    const expectedBytes = [bytes, 65536]
    monitor.on('update', () => {
      t.is(monitor.downloadStats.blocks, expectedBlocks.pop())
      t.is(monitor.downloadStats.monitoringBytes, expectedBytes.pop())
      t.is(monitor.downloadStats.targetBlocks, 2)
      t.is(monitor.downloadStats.targetBytes, bytes)
      t.is(monitor.downloadSpeed(), monitor.downloadStats.speed)
      if (!expectedBlocks.length) t.is(monitor.downloadStats.percentage, 100)
      t.absent(monitor.uploadStats.blocks)
    })
  }

  await mirror.drive.get(file)
})

test('monitor is removed from the Set on close', async (t) => {
  const { drive } = await testenv(t.teardown)
  const monitor = drive.monitor('/example.md')
  await monitor.ready()
  t.is(drive.monitors.size, 1)
  await monitor.close()
  t.is(drive.monitors.size, 0)
})

async function testenv (teardown) {
  const corestore = new Corestore(RAM)
  await corestore.ready()

  const drive = new Hyperdrive(corestore)
  await drive.ready()
  teardown(drive.close.bind(drive))

  const net = await testnet(2, { teardown })
  const { bootstrap } = net
  const swarm = new Hyperswarm({ dht: new DHT({ bootstrap }) })
  teardown(swarm.destroy.bind(swarm))

  const mirror = {}
  mirror.swarm = new Hyperswarm({ dht: new DHT({ bootstrap }) })
  teardown(mirror.swarm.destroy.bind(mirror.swarm))
  mirror.corestore = new Corestore(RAM)
  mirror.drive = new Hyperdrive(mirror.corestore, drive.key)
  await mirror.drive.ready()
  teardown(mirror.drive.close.bind(mirror.drive))

  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'hyperdrive-test-'))
  const root = __dirname
  const paths = { tmp, root }

  return { net, paths, corestore, drive, swarm, mirror }
}

async function * readdirator (parent, { readdir = fs.readdirSync, isDirectory = (x) => fs.statSync(x).isDirectory(), filter = () => true } = {}) {
  for await (const child of readdir(parent)) {
    const next = path.join(parent, child)
    try {
      if (!filter(child)) continue
      if (await isDirectory(next)) yield * readdirator(next)
      else yield next
    } catch { continue }
  }
}

function filter (x) {
  return !(/node_modules|\.git/.test(x))
}

function downloadShark (core) {
  const telem = { offsets: [], count: 0 }
  core.on('download', (offset) => {
    telem.count++
    telem.offsets.push(offset)
  })
  return telem
}

async function streamToBuffer (stream) {
  const chunks = []
  for await (const chunk of stream) {
    chunks.push(chunk)
  }
  return b4a.concat(chunks)
}

function createTmpDir (t) {
  const tmpdir = path.join(os.tmpdir(), 'hyperdrive-test-')
  const dir = fs.mkdtempSync(tmpdir)
  t.teardown(() => fs.promises.rm(dir, { recursive: true }))
  return dir
}

function eventFlush () {
  return new Promise(resolve => setImmediate(resolve))
}

async function replicate (drive, swarm, mirror) {
  swarm.on('connection', (conn) => drive.corestore.replicate(conn))
  const discovery = swarm.join(drive.discoveryKey, { server: true, client: false })
  await discovery.flushed()

  mirror.swarm.on('connection', (conn) => mirror.corestore.replicate(conn))
  mirror.swarm.join(drive.discoveryKey, { server: false, client: true })
  await mirror.swarm.flush()
}