Function compare

tests/testHelper.js:450–499

 * @param {Array<TestYInstance>} users
 */
export const compare = users => {
  users.forEach(u => u.connect())
  while (users[0].tc.flushAllMessages()) {} // eslint-disable-line
  // For each document, merge all received document updates with Y.mergeUpdates and create a new document which will be added to the list of "users"
  // This ensures that mergeUpdates works correctly
  const mergedDocs = users.map(user => {
    const ydoc = new Y.Doc()
    enc.applyUpdate(ydoc, enc.mergeUpdates(user.updates))
    return ydoc
  })
  users.push(.../** @type {any} */(mergedDocs))
  const userArrayValues = users.map(u => u.get('array').toJSON().children ?? [])
  const userMapValues = users.map(u => u.get('map').toJSON().attrs ?? {})
  // @todo fix type error here
  // @ts-ignore
  const userXmlValues = users.map(u => u.get('xml').toString())
  const userTextValues = users.map(u => u.get('text').toDeltaDeep())
  for (const u of users) {
    t.assert(u.store.pendingDs === null)
    t.assert(u.store.pendingStructs === null)
  }
  // Test Map iterator
  const ymapkeys = Array.from(users[0].get('map').attrKeys())
  t.assert(ymapkeys.length === Object.keys(userMapValues[0]).length)
  ymapkeys.forEach(key => t.assert(object.hasProperty(userMapValues[0], key)))
  // Compare all users
  for (let i = 0; i < users.length - 1; i++) {
    t.compare(userArrayValues[i].length, users[i].get('array').length)
    t.compare(userArrayValues[i], userArrayValues[i + 1])
    t.compare(userMapValues[i], userMapValues[i + 1])
    t.compare(userXmlValues[i], userXmlValues[i + 1])
    t.compare(list.toArray(userTextValues[i].children).map(a => (delta.$textOp.check(a) || delta.$insertOp.check(a)) ? a.insert.length : 0).reduce((a, b) => a + b, 0), users[i].get('text').length)
    t.compare(userTextValues[i], userTextValues[i + 1], '', (_constructor, a, b) => {
      if (a instanceof Y.Type) {
        t.compare(a.toJSON(), b.toJSON())
      } else if (a !== b) {
        t.fail('Deltas dont match')
      }
      return true
    })
    t.compare(Y.encodeStateVector(users[i]), Y.encodeStateVector(users[i + 1]))
    Y.equalIdSets(Y.createDeleteSetFromStructStore(users[i].store), Y.createDeleteSetFromStructStore(users[i + 1].store))
    compareStructStores(users[i].store, users[i + 1].store)
    t.compare(Y.encodeSnapshot(Y.snapshot(users[i])), Y.encodeSnapshot(Y.snapshot(users[i + 1])))
  }
  users.forEach(user => {
    compareIdSets(user.store.ds, Y.createDeleteSetFromStructStore(user.store))
  })
  users.map(u => u.destroy())
}

/**
 * @param {Y.Item?} a