diff --git a/test/y-array.tests.js b/test/y-array.tests.js
new file mode 100644
index 00000000..3a49fa32
--- /dev/null
+++ b/test/y-array.tests.js
@@ -0,0 +1,374 @@
+import { wait, initArrays, compareUsers, Y, flushAll, garbageCollectUsers, applyRandomTests } from '../tests-lib/helper.js'
+import { test, proxyConsole } from 'cutest'
+
+proxyConsole()
+
+test('basic spec', async function array0 (t) {
+  let { users, array0 } = await initArrays(t, { users: 2 })
+
+  array0.delete(0, 0)
+  t.assert(true, 'Does not throw when deleting zero elements with position 0')
+
+  let throwInvalidPosition = false
+  try {
+    array0.delete(1, 0)
+  } catch (e) {
+    throwInvalidPosition = true
+  }
+  t.assert(throwInvalidPosition, 'Throws when deleting zero elements with an invalid position')
+
+  array0.insert(0, ['A'])
+  array0.delete(1, 0)
+  t.assert(true, 'Does not throw when deleting zero elements with valid position 1')
+
+  await compareUsers(t, users)
+})
+
+test('insert three elements, try re-get property', async function array1 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 2 })
+  array0.insert(0, [1, 2, 3])
+  t.compare(array0.toArray(), [1, 2, 3], '.toArray() works')
+  await flushAll(t, users)
+  t.compare(array1.toArray(), [1, 2, 3], '.toArray() works after sync')
+  await compareUsers(t, users)
+})
+
+test('concurrent insert (handle three conflicts)', async function array2 (t) {
+  var { users, array0, array1, array2 } = await initArrays(t, { users: 3 })
+  array0.insert(0, [0])
+  array1.insert(0, [1])
+  array2.insert(0, [2])
+
+  await compareUsers(t, users)
+})
+
+test('concurrent insert&delete (handle three conflicts)', async function array3 (t) {
+  var { users, array0, array1, array2 } = await initArrays(t, { users: 3 })
+  array0.insert(0, ['x', 'y', 'z'])
+  await flushAll(t, users)
+  array0.insert(1, [0])
+  array1.delete(0)
+  array1.delete(1, 1)
+  array2.insert(1, [2])
+
+  await compareUsers(t, users)
+})
+
+test('insertions work in late sync', async function array4 (t) {
+  var { users, array0, array1, array2 } = await initArrays(t, { users: 3 })
+  array0.insert(0, ['x', 'y'])
+  await flushAll(t, users)
+  users[1].disconnect()
+  users[2].disconnect()
+  array0.insert(1, ['user0'])
+  array1.insert(1, ['user1'])
+  array2.insert(1, ['user2'])
+  await users[1].reconnect()
+  await users[2].reconnect()
+  await compareUsers(t, users)
+})
+
+test('disconnect really prevents sending messages', async function array5 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 3 })
+  array0.insert(0, ['x', 'y'])
+  await flushAll(t, users)
+  users[1].disconnect()
+  users[2].disconnect()
+  array0.insert(1, ['user0'])
+  array1.insert(1, ['user1'])
+  await wait(1000)
+  t.compare(array0.toArray(), ['x', 'user0', 'y'])
+  t.compare(array1.toArray(), ['x', 'user1', 'y'])
+  await users[1].reconnect()
+  await users[2].reconnect()
+  await compareUsers(t, users)
+})
+
+test('deletions in late sync', async function array6 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 2 })
+  array0.insert(0, ['x', 'y'])
+  await flushAll(t, users)
+  await users[1].disconnect()
+  array1.delete(1, 1)
+  array0.delete(0, 2)
+  await wait()
+  await users[1].reconnect()
+  await compareUsers(t, users)
+})
+
+test('insert, then marge delete on sync', async function array7 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 2 })
+  array0.insert(0, ['x', 'y', 'z'])
+  await flushAll(t, users)
+  await wait()
+  await users[0].disconnect()
+  array1.delete(0, 3)
+  await wait()
+  await users[0].reconnect()
+  await compareUsers(t, users)
+})
+
+function compareEvent (t, is, should) {
+  for (var key in should) {
+    t.assert(
+      should[key] === is[key] ||
+      JSON.stringify(should[key]) === JSON.stringify(is[key])
+    , 'event works as expected'
+    )
+  }
+}
+
+test('insert & delete events', async function array8 (t) {
+  var { array0, users } = await initArrays(t, { users: 2 })
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array0.insert(0, [0, 1, 2])
+  compareEvent(t, event, {
+    type: 'insert',
+    index: 0,
+    values: [0, 1, 2],
+    length: 3
+  })
+  array0.delete(0)
+  compareEvent(t, event, {
+    type: 'delete',
+    index: 0,
+    length: 1,
+    values: [0]
+  })
+  array0.delete(0, 2)
+  compareEvent(t, event, {
+    type: 'delete',
+    index: 0,
+    length: 2,
+    values: [1, 2]
+  })
+  await compareUsers(t, users)
+})
+
+test('insert & delete events for types', async function array9 (t) {
+  var { array0, users } = await initArrays(t, { users: 2 })
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array0.insert(0, [Y.Array])
+  compareEvent(t, event, {
+    type: 'insert',
+    object: array0,
+    index: 0,
+    length: 1
+  })
+  var type = array0.get(0)
+  t.assert(type._model != null, 'Model of type is defined')
+  array0.delete(0)
+  compareEvent(t, event, {
+    type: 'delete',
+    object: array0,
+    index: 0,
+    length: 1
+  })
+  await compareUsers(t, users)
+})
+
+test('insert & delete events for types (2)', async function array10 (t) {
+  var { array0, users } = await initArrays(t, { users: 2 })
+  var events = []
+  array0.observe(function (e) {
+    events.push(e)
+  })
+  array0.insert(0, ['hi', Y.Map])
+  compareEvent(t, events[0], {
+    type: 'insert',
+    object: array0,
+    index: 0,
+    length: 1,
+    values: ['hi']
+  })
+  compareEvent(t, events[1], {
+    type: 'insert',
+    object: array0,
+    index: 1,
+    length: 1
+  })
+  array0.delete(1)
+  compareEvent(t, events[2], {
+    type: 'delete',
+    object: array0,
+    index: 1,
+    length: 1
+  })
+  await compareUsers(t, users)
+})
+
+test('garbage collector', async function gc1 (t) {
+  var { users, array0 } = await initArrays(t, { users: 3 })
+
+  array0.insert(0, ['x', 'y', 'z'])
+  await flushAll(t, users)
+  users[0].disconnect()
+  array0.delete(0, 3)
+  await wait()
+  await users[0].reconnect()
+  await flushAll(t, users)
+  await garbageCollectUsers(t, users)
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a primitive on a YArray (same user)', async function array11 (t) {
+  var { array0, users } = await initArrays(t, { users: 3 })
+
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array0.insert(0, ['stuff'])
+  t.assert(event.values[0] === event.object.get(0), 'compare value with get method')
+  t.assert(event.values[0] === 'stuff', 'check that value is actually present')
+  t.assert(event.values[0] === array0.toArray()[0], '.toArray works as expected')
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a primitive on a YArray (received from another user)', async function array12 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 3 })
+
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array1.insert(0, ['stuff'])
+  await flushAll(t, users)
+  t.assert(event.values[0] === event.object.get(0), 'compare value with get method')
+  t.assert(event.values[0] === 'stuff', 'check that value is actually present')
+  t.assert(event.values[0] === array0.toArray()[0], '.toArray works as expected')
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a type on a YArray (same user)', async function array13 (t) {
+  var { array0, users } = await initArrays(t, { users: 3 })
+
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array0.insert(0, [Y.Array])
+  t.assert(event.values[0] === event.object.get(0), 'compare value with get method')
+  t.assert(event.values[0] != null, 'event.value exists')
+  t.assert(event.values[0] === array0.toArray()[0], '.toArray works as expected')
+  await compareUsers(t, users)
+})
+test('event has correct value when setting a type on a YArray (ops received from another user)', async function array14 (t) {
+  var { users, array0, array1 } = await initArrays(t, { users: 3 })
+
+  var event
+  array0.observe(function (e) {
+    event = e
+  })
+  array1.insert(0, [Y.Array])
+  await flushAll(t, users)
+  t.assert(event.values[0] === event.object.get(0), 'compare value with get method')
+  t.assert(event.values[0] != null, 'event.value exists')
+  t.assert(event.values[0] === array0.toArray()[0], '.toArray works as expected')
+  await compareUsers(t, users)
+})
+
+var _uniqueNumber = 0
+function getUniqueNumber () {
+  return _uniqueNumber++
+}
+
+var arrayTransactions = [
+  function insert (t, user, chance) {
+    var uniqueNumber = getUniqueNumber()
+    var content = []
+    var len = chance.integer({ min: 1, max: 4 })
+    for (var i = 0; i < len; i++) {
+      content.push(uniqueNumber)
+    }
+    var pos = chance.integer({ min: 0, max: user.share.array.length })
+    user.share.array.insert(pos, content)
+  },
+  function insertTypeArray (t, user, chance) {
+    var pos = chance.integer({ min: 0, max: user.share.array.length })
+    user.share.array.insert(pos, [Y.Array])
+    var array2 = user.share.array.get(pos)
+    array2.insert(0, [1, 2, 3, 4])
+  },
+  function insertTypeMap (t, user, chance) {
+    var pos = chance.integer({ min: 0, max: user.share.array.length })
+    user.share.array.insert(pos, [Y.Map])
+    var map = user.share.array.get(pos)
+    map.set('someprop', 42)
+    map.set('someprop', 43)
+    map.set('someprop', 44)
+  },
+  function _delete (t, user, chance) {
+    var length = user.share.array._content.length
+    if (length > 0) {
+      var pos = chance.integer({ min: 0, max: length - 1 })
+      var delLength = chance.integer({ min: 1, max: Math.min(2, length - pos) })
+      if (user.share.array._content[pos].type != null) {
+        if (chance.bool()) {
+          var type = user.share.array.get(pos)
+          if (type instanceof Y.Array.typeDefinition.class) {
+            if (type._content.length > 0) {
+              pos = chance.integer({ min: 0, max: type._content.length - 1 })
+              delLength = chance.integer({ min: 0, max: Math.min(2, type._content.length - pos) })
+              type.delete(pos, delLength)
+            }
+          } else {
+            type.delete('someprop')
+          }
+        } else {
+          user.share.array.delete(pos, delLength)
+        }
+      } else {
+        user.share.array.delete(pos, delLength)
+      }
+    }
+  }
+]
+
+test('y-array: Random tests (42)', async function randomArray42 (t) {
+  await applyRandomTests(t, arrayTransactions, 42)
+})
+
+test('y-array: Random tests (43)', async function randomArray43 (t) {
+  await applyRandomTests(t, arrayTransactions, 43)
+})
+
+test('y-array: Random tests (44)', async function randomArray44 (t) {
+  await applyRandomTests(t, arrayTransactions, 44)
+})
+
+test('y-array: Random tests (45)', async function randomArray45 (t) {
+  await applyRandomTests(t, arrayTransactions, 45)
+})
+
+test('y-array: Random tests (46)', async function randomArray46 (t) {
+  await applyRandomTests(t, arrayTransactions, 46)
+})
+
+test('y-array: Random tests (47)', async function randomArray47 (t) {
+  await applyRandomTests(t, arrayTransactions, 47)
+})
+
+/*
+test('y-array: Random tests (200)', async function randomArray200 (t) {
+  await applyRandomTests(t, arrayTransactions, 200)
+})
+
+test('y-array: Random tests (300)', async function randomArray300 (t) {
+  await applyRandomTests(t, arrayTransactions, 300)
+})
+
+test('y-array: Random tests (400)', async function randomArray400 (t) {
+  await applyRandomTests(t, arrayTransactions, 400)
+})
+
+test('y-array: Random tests (500)', async function randomArray500 (t) {
+  await applyRandomTests(t, arrayTransactions, 500)
+})
+*/
diff --git a/test/y-map.tests.js b/test/y-map.tests.js
new file mode 100644
index 00000000..9b424f4a
--- /dev/null
+++ b/test/y-map.tests.js
@@ -0,0 +1,371 @@
+import { initArrays, compareUsers, Y, flushAll, applyRandomTests } from '../tests-lib/helper.js'
+import { test, proxyConsole } from 'cutest'
+
+proxyConsole()
+
+test('basic map tests', async function map0 (t) {
+  let { users, map0, map1, map2 } = await initArrays(t, { users: 3 })
+  users[2].disconnect()
+
+  map0.set('number', 1)
+  map0.set('string', 'hello Y')
+  map0.set('object', { key: { key2: 'value' } })
+  map0.set('y-map', Y.Map)
+  let map = map0.get('y-map')
+  map.set('y-array', Y.Array)
+  let array = map.get('y-array')
+  array.insert(0, [0])
+  array.insert(0, [-1])
+
+  t.assert(map0.get('number') === 1, 'client 0 computed the change (number)')
+  t.assert(map0.get('string') === 'hello Y', 'client 0 computed the change (string)')
+  t.compare(map0.get('object'), { key: { key2: 'value' } }, 'client 0 computed the change (object)')
+  t.assert(map0.get('y-map').get('y-array').get(0) === -1, 'client 0 computed the change (type)')
+
+  await users[2].reconnect()
+  await flushAll(t, users)
+
+  t.assert(map1.get('number') === 1, 'client 1 received the update (number)')
+  t.assert(map1.get('string') === 'hello Y', 'client 1 received the update (string)')
+  t.compare(map1.get('object'), { key: { key2: 'value' } }, 'client 1 received the update (object)')
+  t.assert(map1.get('y-map').get('y-array').get(0) === -1, 'client 1 received the update (type)')
+
+  // compare disconnected user
+  t.assert(map2.get('number') === 1, 'client 2 received the update (number) - was disconnected')
+  t.assert(map2.get('string') === 'hello Y', 'client 2 received the update (string) - was disconnected')
+  t.compare(map2.get('object'), { key: { key2: 'value' } }, 'client 2 received the update (object) - was disconnected')
+  t.assert(map2.get('y-map').get('y-array').get(0) === -1, 'client 2 received the update (type) - was disconnected')
+  await compareUsers(t, users)
+})
+
+test('Basic get&set of Map property (converge via sync)', async function map1 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  map0.set('stuff', 'stuffy')
+  t.compare(map0.get('stuff'), 'stuffy')
+
+  await flushAll(t, users)
+
+  for (let user of users) {
+    var u = user.share.map
+    t.compare(u.get('stuff'), 'stuffy')
+  }
+  await compareUsers(t, users)
+})
+
+test('Map can set custom types (Map)', async function map2 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  var map = map0.set('Map', Y.Map)
+  map.set('one', 1)
+  map = map0.get('Map')
+  t.compare(map.get('one'), 1)
+  await compareUsers(t, users)
+})
+
+test('Map can set custom types (Map) - get also returns the type', async function map3 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  map0.set('Map', Y.Map)
+  var map = map0.get('Map')
+  map.set('one', 1)
+  map = map0.get('Map')
+  t.compare(map.get('one'), 1)
+  await compareUsers(t, users)
+})
+
+test('Map can set custom types (Array)', async function map4 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  var array = map0.set('Array', Y.Array)
+  array.insert(0, [1, 2, 3])
+  array = map0.get('Array')
+  t.compare(array.toArray(), [1, 2, 3])
+  await compareUsers(t, users)
+})
+
+test('Basic get&set of Map property (converge via update)', async function map5 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  map0.set('stuff', 'stuffy')
+  t.compare(map0.get('stuff'), 'stuffy')
+
+  await flushAll(t, users)
+
+  for (let user of users) {
+    var u = user.share.map
+    t.compare(u.get('stuff'), 'stuffy')
+  }
+  await compareUsers(t, users)
+})
+
+test('Basic get&set of Map property (handle conflict)', async function map6 (t) {
+  let { users, map0, map1 } = await initArrays(t, { users: 3 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+
+  await flushAll(t, users)
+
+  for (let user of users) {
+    var u = user.share.map
+    t.compare(u.get('stuff'), 'c0')
+  }
+  await compareUsers(t, users)
+})
+
+test('Basic get&set&delete of Map property (handle conflict)', async function map7 (t) {
+  let { users, map0, map1 } = await initArrays(t, { users: 3 })
+  map0.set('stuff', 'c0')
+  map0.delete('stuff')
+  map1.set('stuff', 'c1')
+  await flushAll(t, users)
+  for (let user of users) {
+    var u = user.share.map
+    t.assert(u.get('stuff') === undefined)
+  }
+  await compareUsers(t, users)
+})
+
+test('Basic get&set of Map property (handle three conflicts)', async function map8 (t) {
+  let { users, map0, map1, map2 } = await initArrays(t, { users: 3 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.set('stuff', 'c2')
+  map2.set('stuff', 'c3')
+  await flushAll(t, users)
+  for (let user of users) {
+    var u = user.share.map
+    t.compare(u.get('stuff'), 'c0')
+  }
+  await compareUsers(t, users)
+})
+
+test('Basic get&set&delete of Map property (handle three conflicts)', async function map9 (t) {
+  let { users, map0, map1, map2, map3 } = await initArrays(t, { users: 4 })
+  map0.set('stuff', 'c0')
+  map1.set('stuff', 'c1')
+  map1.set('stuff', 'c2')
+  map2.set('stuff', 'c3')
+  await flushAll(t, users)
+  map0.set('stuff', 'deleteme')
+  map0.delete('stuff')
+  map1.set('stuff', 'c1')
+  map2.set('stuff', 'c2')
+  map3.set('stuff', 'c3')
+  await flushAll(t, users)
+  for (let user of users) {
+    var u = user.share.map
+    t.assert(u.get('stuff') === undefined)
+  }
+  await compareUsers(t, users)
+})
+
+test('observePath properties', async function map10 (t) {
+  let { users, map0, map1, map2 } = await initArrays(t, { users: 3 })
+  let map
+  map0.observePath(['map'], function (map) {
+    if (map != null) {
+      map.set('yay', 4)
+    }
+  })
+  map1.set('map', Y.Map)
+  await flushAll(t, users)
+  map = map2.get('map')
+  t.compare(map.get('yay'), 4)
+  await compareUsers(t, users)
+})
+
+test('observe deep properties', async function map11 (t) {
+  let { users, map1, map2, map3 } = await initArrays(t, { users: 4 })
+  var _map1 = map1.set('map', Y.Map)
+  var calls = 0
+  var dmapid
+  _map1.observe(function (event) {
+    calls++
+    t.compare(event.name, 'deepmap')
+    dmapid = event.object.opContents.deepmap
+  })
+  await flushAll(t, users)
+  var _map3 = map3.get('map')
+  _map3.set('deepmap', Y.Map)
+  await flushAll(t, users)
+  var _map2 = map2.get('map')
+  _map2.set('deepmap', Y.Map)
+  await flushAll(t, users)
+  var dmap1 = _map1.get('deepmap')
+  var dmap2 = _map2.get('deepmap')
+  var dmap3 = _map3.get('deepmap')
+  t.assert(calls > 0)
+  t.compare(dmap1._model, dmap2._model)
+  t.compare(dmap1._model, dmap3._model)
+  t.compare(dmap1._model, dmapid)
+  await compareUsers(t, users)
+})
+
+test('observes using observePath', async function map12 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  var pathes = []
+  var calls = 0
+  map0.observeDeep(function (event) {
+    pathes.push(event.path)
+    calls++
+  })
+  map0.set('map', Y.Map)
+  map0.get('map').set('array', Y.Array)
+  map0.get('map').get('array').insert(0, ['content'])
+  t.assert(calls === 3)
+  t.compare(pathes, [[], ['map'], ['map', 'array']])
+  await compareUsers(t, users)
+})
+
+function compareEvent (t, is, should) {
+  for (var key in should) {
+    t.assert(should[key] === is[key])
+  }
+}
+
+test('throws add & update & delete events (with type and primitive content)', async function map13 (t) {
+  let { users, map0 } = await initArrays(t, { users: 2 })
+  var event
+  await flushAll(t, users)
+  map0.observe(function (e) {
+    event = e // just put it on event, should be thrown synchronously anyway
+  })
+  map0.set('stuff', 4)
+  compareEvent(t, event, {
+    type: 'add',
+    object: map0,
+    name: 'stuff'
+  })
+  // update, oldValue is in contents
+  map0.set('stuff', Y.Array)
+  compareEvent(t, event, {
+    type: 'update',
+    object: map0,
+    name: 'stuff',
+    oldValue: 4
+  })
+  var replacedArray = map0.get('stuff')
+  // update, oldValue is in opContents
+  map0.set('stuff', 5)
+  var array = event.oldValue
+  t.compare(array._model, replacedArray._model)
+  // delete
+  map0.delete('stuff')
+  compareEvent(t, event, {
+    type: 'delete',
+    name: 'stuff',
+    object: map0,
+    oldValue: 5
+  })
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a primitive on a YMap (same user)', async function map14 (t) {
+  let { users, map0 } = await initArrays(t, { users: 3 })
+  var event
+  await flushAll(t, users)
+  map0.observe(function (e) {
+    event = e
+  })
+  map0.set('stuff', 2)
+  t.compare(event.value, event.object.get(event.name))
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a primitive on a YMap (received from another user)', async function map15 (t) {
+  let { users, map0, map1 } = await initArrays(t, { users: 3 })
+  var event
+  await flushAll(t, users)
+  map0.observe(function (e) {
+    event = e
+  })
+  map1.set('stuff', 2)
+  await flushAll(t, users)
+  t.compare(event.value, event.object.get(event.name))
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a type on a YMap (same user)', async function map16 (t) {
+  let { users, map0 } = await initArrays(t, { users: 3 })
+  var event
+  await flushAll(t, users)
+  map0.observe(function (e) {
+    event = e
+  })
+  map0.set('stuff', Y.Map)
+  t.compare(event.value._model, event.object.get(event.name)._model)
+  await compareUsers(t, users)
+})
+
+test('event has correct value when setting a type on a YMap (ops received from another user)', async function map17 (t) {
+  let { users, map0, map1 } = await initArrays(t, { users: 3 })
+  var event
+  await flushAll(t, users)
+  map0.observe(function (e) {
+    event = e
+  })
+  map1.set('stuff', Y.Map)
+  await flushAll(t, users)
+  t.compare(event.value._model, event.object.get(event.name)._model)
+  await compareUsers(t, users)
+})
+
+var mapTransactions = [
+  function set (t, user, chance) {
+    let key = chance.pickone(['one', 'two'])
+    var value = chance.string()
+    user.share.map.set(key, value)
+  },
+  function setType (t, user, chance) {
+    let key = chance.pickone(['one', 'two'])
+    var value = chance.pickone([Y.Array, Y.Map])
+    let type = user.share.map.set(key, value)
+    if (value === Y.Array) {
+      type.insert(0, [1, 2, 3, 4])
+    } else {
+      type.set('deepkey', 'deepvalue')
+    }
+  },
+  function _delete (t, user, chance) {
+    let key = chance.pickone(['one', 'two'])
+    user.share.map.delete(key)
+  }
+]
+
+test('y-map: Random tests (42)', async function randomMap42 (t) {
+  await applyRandomTests(t, mapTransactions, 42)
+})
+
+test('y-map: Random tests (43)', async function randomMap43 (t) {
+  await applyRandomTests(t, mapTransactions, 43)
+})
+
+test('y-map: Random tests (44)', async function randomMap44 (t) {
+  await applyRandomTests(t, mapTransactions, 44)
+})
+
+test('y-map: Random tests (45)', async function randomMap45 (t) {
+  await applyRandomTests(t, mapTransactions, 45)
+})
+
+test('y-map: Random tests (46)', async function randomMap46 (t) {
+  await applyRandomTests(t, mapTransactions, 46)
+})
+
+test('y-map: Random tests (47)', async function randomMap47 (t) {
+  await applyRandomTests(t, mapTransactions, 47)
+})
+
+/*
+test('y-map: Random tests (200)', async function randomMap200 (t) {
+  await applyRandomTests(t, mapTransactions, 200)
+})
+
+test('y-map: Random tests (300)', async function randomMap300 (t) {
+  await applyRandomTests(t, mapTransactions, 300)
+})
+
+test('y-map: Random tests (400)', async function randomMap400 (t) {
+  await applyRandomTests(t, mapTransactions, 400)
+})
+
+test('y-map: Random tests (500)', async function randomMap500 (t) {
+  await applyRandomTests(t, mapTransactions, 500)
+})
+*/
diff --git a/tests-lib/helper.js b/tests-lib/helper.js
index 6a96a073..aef1c1a2 100644
--- a/tests-lib/helper.js
+++ b/tests-lib/helper.js
@@ -12,6 +12,9 @@ export let Y = _Y
 
 Y.extend(yMemory, yArray, yMap, yTest)
 
+export var database = { name: 'memory' }
+export var connector = { name: 'test', url: 'http://localhost:1234' }
+
 function * getStateSet () {
   var ss = {}
   yield * this.ss.iterate(this, null, null, function * (n) {
@@ -60,7 +63,16 @@ export async function compareUsers (t, users) {
   await wait()
   await flushAll(t, users)
 
-  var userTypeContents = users.map(u => u.share.array._content.map(c => c.val || JSON.stringify(c.type)))
+  var userArrayValues = users.map(u => u.share.array._content.map(c => c.val || JSON.stringify(c.type)))
+  function valueToComparable (v) {
+    if (v != null && v._model != null) {
+      return v._model
+    } else {
+      return v || null
+    }
+  }
+  var userMapOneValues = users.map(u => u.share.map.get('one')).map(valueToComparable)
+  var userMapTwoValues = users.map(u => u.share.map.get('two')).map(valueToComparable)
 
   await users[0].db.garbageCollect()
   await users[0].db.garbageCollect()
@@ -118,7 +130,9 @@ export async function compareUsers (t, users) {
   }))
   for (var i = 0; i < data.length - 1; i++) {
     await t.asyncGroup(async () => {
-      t.compare(userTypeContents[i], userTypeContents[i + 1], 'types')
+      t.compare(userArrayValues[i], userArrayValues[i + 1], 'array types')
+      t.compare(userMapOneValues[i], userMapOneValues[i + 1], 'map types (propery "one")')
+      t.compare(userMapTwoValues[i], userMapTwoValues[i + 1], 'map types (propery "two")')
       t.compare(data[i].os, data[i + 1].os, 'os')
       t.compare(data[i].ds, data[i + 1].ds, 'ds')
       t.compare(data[i].ss, data[i + 1].ss, 'ss')
@@ -135,17 +149,17 @@ export async function initArrays (t, opts) {
   }
   var share = Object.assign({ flushHelper: 'Map', array: 'Array', map: 'Map' }, opts.share)
   var chance = opts.chance || new Chance(t.getSeed() * 1000000000)
-  var connector = Object.assign({ room: 'debugging_' + t.name, generateUserId: false, testContext: t, chance }, opts.connector)
+  var conn = Object.assign({ room: 'debugging_' + t.name, generateUserId: false, testContext: t, chance }, connector)
   for (let i = 0; i < opts.users; i++) {
     let dbOpts
     let connOpts
     if (i === 0) {
       // Only one instance can gc!
-      dbOpts = Object.assign({ gc: false }, opts.db)
-      connOpts = Object.assign({ role: 'master' }, connector)
+      dbOpts = Object.assign({ gc: false }, database)
+      connOpts = Object.assign({ role: 'master' }, conn)
     } else {
-      dbOpts = Object.assign({ gc: false }, opts.db)
-      connOpts = Object.assign({ role: 'slave' }, connector)
+      dbOpts = Object.assign({ gc: false }, database)
+      connOpts = Object.assign({ role: 'slave' }, conn)
     }
     let y = await Y({
       connector: connOpts,
@@ -220,3 +234,48 @@ export function wait (t) {
     setTimeout(resolve, t != null ? t : 100)
   })
 }
+
+export async function applyRandomTests (t, mods, iterations) {
+  const chance = new Chance(t.getSeed() * 1000000000)
+  var initInformation = await initArrays(t, { users: 5, chance: chance })
+  let { users } = initInformation
+  for (var i = 0; i < iterations; i++) {
+    if (chance.bool({likelihood: 10})) {
+      // 10% chance to disconnect/reconnect a user
+      // we make sure that the first users always is connected
+      let user = chance.pickone(users.slice(1))
+      if (user.connector.isSynced) {
+        if (users.filter(u => u.connector.isSynced).length > 1) {
+          // make sure that at least one user remains in the room
+          await user.disconnect()
+          if (users[0].connector.testRoom == null) {
+            await wait(100)
+          }
+        }
+      } else {
+        await user.reconnect()
+        if (users[0].connector.testRoom == null) {
+          await wait(100)
+        }
+        await new Promise(function (resolve) {
+          user.connector.whenSynced(resolve)
+        })
+      }
+    } else if (chance.bool({likelihood: 5})) {
+      // 20%*!prev chance to flush all & garbagecollect
+      // TODO: We do not gc all users as this does not work yet
+      // await garbageCollectUsers(t, users)
+      await flushAll(t, users)
+      await users[0].db.emptyGarbageCollector()
+      await flushAll(t, users)
+    } else if (chance.bool({likelihood: 10})) {
+      // 20%*!prev chance to flush some operations
+      await flushSome(t, users)
+    }
+    let user = chance.pickone(users)
+    var test = chance.pickone(mods)
+    test(t, user, chance)
+  }
+  await compareUsers(t, users)
+  return initInformation
+}