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const wait = () => new Promise((r) => setTimeout(r, 10));

const fakeDbOp = async () => {
  console.log("fakeDbOp");
  await wait(10);
  return 1;
};

const fakeTrxDbOp = async () => {
  console.log("fakeTrxDbOp");

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  // Available variables:
  // - Machine
  // - interpret
  // - assign
  // - send
  // - sendParent
  // - spawn
  // - raise
  // - actions

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export const isMainThread = () => typeof window !== 'undefined' && typeof importScripts === 'function'

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import isNil from 'lodash/isNil'
import { createPubSub } from 'https://gist.githubusercontent.com/mfbx9da4/896c0fa0439da9f87aab1883ec586b30/raw/808023dd8a1c014ebe81ff4d17d2748fddf8dc62/createPubSub.ts'
import { uuid } from 'short-uuid'
import { isMainThread } from 'https://gist.githubusercontent.com/mfbx9da4/de9e6a398d1847a0d11e5a20256bd0d9/raw/f8979aa8b241e778996cfda71398b42af0994202/isMainThread.ts'
import { createDeferredPromise } from 'https://gist.githubusercontent.com/mfbx9da4/76baa3051bbd044de18d1c1ac0c254dd/raw/853e5169f69a0c1cefe12816ff1ba25b36c1d366/createDeferredPromise.ts'
/**
 * The goal of this module is to keep track of the navigation history
 * in a single page app. It monitors `push()`, `back()`, `forward()` and
 * `replace()` navigation events. It offers a number of features that
 * the native history API does not support:

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import { createObservable as createObservableInner } from 'onin-shared/build/createObservable'
import { useEffect, useState } from 'react'
import { isMainThread } from './isMainThread'

export type Key = string
export type Value = string | undefined
const createObservable = (x: Value) => createObservableInner(x)
type Observable = ReturnType<typeof createObservable>

const Observables = {

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class VersionedMap {
  constructor(iterableOrMap, version = 0) {
    this.map =
      iterableOrMap instanceof Map ? iterableOrMap : new Map(iterableOrMap);
    this.version = version;
    this.mutated = false;
  }

  set(key, value) {
    if (this.map.get(key) !== value) {

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class Foo {
	public a string
	public b number
}

function getDefault(fieldAsString: 'a' | 'b') {
	if (field === 'a') return 'asdf'
	if (field === 'b') return 3
}

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Javascript is single threaded but it is not by any means immue to race conditions. Below is a swiss army knife of ways to deal with race conditions.

Single process

• In memory queues
• Mutexes

Multi process

• UPDATE commands
• Queues

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const fs = require("fs");

const acquireLock = async (identifier, retries = 5, delay = 1000) => {
  const pathname = `${identifier}.lock`;
  const acquire = () => {
    try {
      fs.mkdirSync(pathname);
      return true;
    } catch {}
  };

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Machine({
  id: 'Scroll view',
  initial: 'chat_closed',
  context: {
    dog: null
  },
  states: {
    chat_closed: {
      on: {
        open: 'chat_open'