Damian Mullins DamianMullins

This document has moved to: https://anthonysteele.github.io/AsyncBasicMistakes

I see a lot of code lately that makes some simple mistakes using the async ... await construct.

TL;DR

A Task is a promise of a value.

[based on a true story]

So. Your friend's about to teach you how to make a website. Great!

You make a file, and you save it as 'index.html'. Why it's called 'index' isn't really explained to you, but whatever.

You type the following.

hello world

One-line browser notepad 📝

Sometimes you just need to quickly take some notes.

A trick is to use the data: scheme with data:text/html to show just a piece of HTML in your browser. Then using the mighty contentEditable to make the whole thing editable.

To copy/paste into your browser address bar:

data:text/html,<html contenteditable>

Speed is a feature: 10 tips for faster browser networking

1. Minimize TCP connections

Ensure the web server uses Keep-Alive headers.

2. Reduce DNS look-ups

DNS look-ups are the first thing blocking your HTTP requests.

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

~~Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.~~

Using `<details>` in GitHub

Suppose you're opening an issue and there's a lot noisey logs that may be useful.

Rather than wrecking readability, wrap it in a <details> tag!

<details>
 Summary Goes Here

Minimum Viable Async with Node 6

With the release of Node 6.0.0, the surface of code that needs transpilation to use ES6 features has been reduced very dramatically.

This is what my current workflow looks like to set up a minimalistic and fast microservice using micro and async + await.

The promise

CLI: Output the difference between 2 files

Thinking of using diff? Try comm, its sole purpose is to compare 2 sorted files line by line.

Show lines in A.txt but NOT in B.txt:

comm -2 -3 A.txt B.txt

If the files aren’t sorted, use:

	{
	if (window.runTTS === undefined) {
	const MAX_TRIES = 20;
	const TRY_DELAY = 100;
	/* Adjust voice speed. Default = 1 */
	if (navigator.userAgent.includes("Macintosh")) {
	window.ttsPlaybackSpeed = 1.2;
	} else if (navigator.userAgent.includes("Windows")) {
	window.ttsPlaybackSpeed = 5;
	} else {

	import React from "react";
	import { render } from "react-dom";

	const ParentComponent = React.createClass({
	getDefaultProps: function() {
	console.log("ParentComponent - getDefaultProps");
	},
	getInitialState: function() {
	console.log("ParentComponent - getInitialState");
	return { text: "" };