Yekeen Ajeigbe klummy

https://twitter.com/snookca/status/1073299331262889984?s=21

‪“‬In what way is JS any more maintainable than CSS? How does writing CSS in JS make it any more maintainable?”

‪Happy to chat about this. There’s an obvious disclaimer that there’s a cost to css-in-js solutions, but that cost is paid specifically for the benefits it brings; as such it’s useful for some usecases, and not meant as a replacement for all workflows. ‬

‪(These conversations always get heated on twitter, so please believe that I’m here to converse, not to convince. In return, I promise to listen to you too and change my opinions; I’ve had mad respect for you for years and would consider your feedback a gift. Also, some of the stuff I’m writing might seem obvious to you; I’m not trying to tell you if all people of some of the details, but it might be useful to someone else who bumps into this who doesn’t have context)‬

So the big deal about css-in-js (cij) is selectors.

This API was removed in React 17

Interaction tracing with React

React recently introduced an experimental profiler API. After discussing this API with several teams at Facebook, one common piece of feedback was that the performance information would be more useful if it could be associated with the events that caused the application to render (e.g. button click, XHR response). Tracing these events (or "interactions") would enable more powerful tooling to be built around the timing information, capable of answering questions like "What caused this really slow commit?" or "How long does it typically take for this interaction to update the DOM?".

With version 16.4.3, React added experimental support for this tracing by way of a new NPM package, scheduler. However the public API for this package is not yet finalized and will likely change with upcoming minor releases, so it should be used with caution.

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

	PROJECT_NAME="gameofthrones"

	CURRENT_DOCKER_COMPOSE_VERSION=$( docker-compose -v \| grep -o '[0-9][.][0-9][.][0-9]' \| sed -e 's/[.]//g' )
	BREAKING_DOCKER_COMPOSE_VERSION=1210

	# Since docker compose version: '1.21.0', the network setup automatically adds a single '_' to the project_name,
	# while version '1.20.0' and below replaces any extra ‘_’ at the end of the project_name with a single '_'.
	# This assumes that at versions below '1.20.0' e.g. '1.9.0', no ‘_’ is added at the end of the project_name.
	if [[ ${CURRENT_DOCKER_COMPOSE_VERSION} -lt ${BREAKING_DOCKER_COMPOSE_VERSION} ]]; then
	PROJECT_NAME="${PROJECT_NAME}_"

	package main

	import (
	"fmt"
	"log"
	"net/http"
	)

	func init() {
	log.SetFlags(log.Lshortfile)

	function backup() {
	function downloadBlob(filename, blobUrl) {
	var element = document.createElement('a');
	element.setAttribute('href', blobUrl);
	element.setAttribute('download', filename);
	element.style.display = 'none';
	document.body.appendChild(element);
	element.click();
	document.body.removeChild(element);
	}

	package main

	import (
	"github.com/graphql-go/graphql"
	"github.com/graphql-go/handler"
	"net/http"
	)

	type Todo struct {
	ID string `json:"id"`

	//
	// Implementation using express-jwt middle
	//
	var express = require('express'),
	ejwt = require('express-jwt'),
	jwt = require('jsonwebtoken'),
	passport = require('passport'),
	bodyParser = require('body-parser'),
	LocalStrategy = require('passport-local').Strategy,
	BearerStrategy = require('passport-http-bearer').Strategy;