dtmrc

Edit — February 2019

This gist had a far larger impact than I imagined it would, and apparently people are still finding it, so a quick update:

TC39 is currently moving forward with a slightly different version of TLA, referred to as 'variant B', in which a module with TLA doesn't block sibling execution. This vastly reduces the danger of parallelizable work happening in serial and thereby delaying startup, which was the concern that motivated me to write this gist
In the wild, we're seeing (async main(){...}()) as a substitute for TLA. This completely eliminates the blocking problem (yay!) but it's less powerful, and harder to statically analyse (boo). In other words the lack of TLA is causing real problems
Therefore, a version of TLA that solves the original issue is a valuable addition to the language, and I'm in full support of the current proposal, which you can read here.

I'll leave the rest of this document unedited, for archaeological

Dynamic module loading done right

Follow-up to Top-level await is a footgun – maybe read that first

Here are some things I believe to be true:

Static module syntax is beneficial in lots of ways – code is easier to write (you get better linting etc) and easier to optimise (tree-shaking and other things that are only really possible with static syntax), and most importantly, faster to load (it's trivial for a module loader to load multiple dependencies concurrently when they're declared with a static syntax – not so with imperative statements like require(...) or await import(...)).
App startup time is perhaps when performance is most critical. (You already know this, I don't need to cite the studies.)
If you're in favour of constructs that jeopardise app startup time, you are anti-user. Top-level await is such a construct.

Migration

This a (probably very bad) migration guide for users moving from generic-pool@2 to generic-pool@3. If there are any improvements you think should be made please let me know via email/twitter or the issue tracker as github issues don't have notifications for comments.

Prerequisites

This module requires nodejs v4 or above as it has dependencies on various es6 components such as Map, Set, Promise etc. I have some vague intetion to create another module that shims out those dependencies or allows user supplied implementations to allow people on node 0.10 to use this module.

Changes

React Native Trouble

Updating to macOS Sierra is causing trouble with React Native due to some of the Node.js and system utilities it uses. Specifically the watch utility fails due to a limit on the number of files which can be opened at a time.

The following command shows the current limit.

launchctl limit maxfiles

Step 1 - Make a Discord Webhook

Find the Discord channel in which you would like to send commits and other updates
In the settings for that channel, find the Webhooks option and create a new webhook. Note: Do NOT give this URL out to the public. Anyone or service can post messages to this channel, without even needing to be in the server. Keep it safe!

Step 2 - Set up the webhook on Github

Navigate to your repository on Github, and open the Settings

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

	Promise.race([
	fetch('/foo'),
	new Promise((_, reject) =>
	setTimeout(() => reject(new Error('Timeout')), 7000)
	)
	]);

	'use strict';

	// run using this fork of NodeJS
	// https://github.com/targos/node/commits/v8-5.4 (https://github.com/nodejs/node/pull/8317)
	//
	// node --harmony_async_await await_thenables.js

	function counter(count) {
	return {
	then: function(res, rej) {

	brew install openssl
	export OPENSSL_INCLUDE_DIR=`brew --prefix openssl`/include
	export OPENSSL_LIB_DIR=`brew --prefix openssl`/lib
	export DEP_OPENSSL_INCLUDE=`brew --prefix openssl`/include

	function dec2hexString(dec) {
	return '0x' + (dec+0x10000).toString(16).substr(-4).toUpperCase();
	}