Rich-Harris

You have an array. Its sort order doesn't matter. You want to remove an item from this array.

The obvious thing to do would be to use splice:

function remove(array, item) {
  const index = array.indexOf(item);
  array.splice(index, 1);
}

Rich-Harris

Rollup 0.48 introduces a few changes to the options object, because the current options are confusingly different between the CLI and the options exported by your config file.

Changes to the config file

• entry is now input
• sourceMap and sourceMapFile are now sourcemap and sourcemapFile (note casing)
• moduleName is now name
• useStrict is now strict

The dest and format options are now grouped together as a single output: { file, format, ... } object. output can also be an array of { file, format, ... } objects, in which case it behaves similarly to the current targets. Other output options — exports, paths and so on — can be added to the output object (though they will fall back to their top-level namesakes, if unspecified).

Rich-Harris

node_modules

Rich-Harris

I saw this poll on Twitter earlier and was surprised at the result, which at the time of writing overwhelmingly favours option 1:

I've always been of the opinion that the (req, res, next) => {} API is the worst of all possible worlds, so one of two things is happening:

• I'm an idiot with bad opinions (very possibly!)
• People like familiarity

Rich-Harris

( function ( global ) {

	'use strict';

	var Promise, PENDING = {}, FULFILLED = {}, REJECTED = {};

	if ( typeof global.Promise === 'function' ) {
		Promise = global.Promise;
	} else {
		Promise = function ( callback ) {

Rich-Harris

Am planning to open source this when I get some breathing room, but a gist will do for now.

Usage:

<Scroller top=0.2 bottom=0.8 threshold=0.5 bind:index bind:offset bind:progress parallax>
  <div slot='background'>
    <!-- fixed, or parallaxing (if the parallax option is set) background -->
  </div>

Rich-Harris

Note: I'm not involved in Prepack in any way — please correct me if I say anything incorrect below!

A few people have asked me if Prepack and Svelte are similar projects with similar goals. The answer is 'no, they're not', but let's take a moment to explore why.

What is Prepack?

Prepack describes itself as a 'partial evaluator for JavaScript'. What that means is that it will run your code in a specialised interpreter that, rather than having some effect on the world (like printing a message to the console), will track the effects that would have happened and express them more directly.

So for example if you give it this code...

Rich-Harris

// addEventListener polyfill IE6+
if ( !window.addEventListener ) {
	(function ( win, doc ) {
		var Event, addEventListener, removeEventListener, head, style;

		Event = function ( e, element ) {
			var property, instance = this;

			for ( property in e ) {
				instance[ property ] = e[ property ];

Rich-Harris

Non-deterministic module ordering is an even bigger footgun

Update – in the comments below, @bmeck clarifies that statically imported modules do evaluate in a deterministic sequential order, contra the Hacker News comments that prompted this gist.

Another follow-up to Top-level await is a footgun. On the Hacker News comments, Domenic says this:

(The argument also seems to be predicated on some fundamental misunderstandings, in that it thinks everything would have to be sequentialized. See my other replies throughout this thread.)

In other words, if you have an app like this...

Rich-Harris

From http://concord-consortium.github.io/developer-notes/automating-gh-pages-integration.html:

How to setup a git repo so gh-pages automatically tracks commits to master and ‘git push origin’ updates the remote master and gh-pages branches.

Setup a test repo:

mkdir pages-test
cd pages-test/
git init .