ChrisDobby

namespace Visitor

type IPrescription =
    abstract member Accept : IPrescriptionVisitor -> unit

and IPrescriptionVisitor =
    abstract member Visit : PointInTime -> unit
    abstract member Visit : Infusion -> unit

and PointInTime() =

ChrisDobby

const ClassName = () => {
    const createdClasses = [];

    const stringToCss = str => str.split('').map(c => c.charCodeAt(0) >= 97
        ? c
        : `-${String.fromCharCode(c.charCodeAt(0) + 32)}`).join('');
    
    const cssString = css => Object.keys(css).map(key => `${stringToCss(key)}:${css[key]}`).join(';');

    const addStyle = (name, css) => {

ChrisDobby

require('colors');
const lighthouse = require('lighthouse');
const chromeLauncher = require('chrome-launcher');

const launchAndRun = (url, opts, config = null) =>
    chromeLauncher.launch({ chromeFlags: opts.chromeFlags })
        .then(chrome => {
            opts.port = chrome.port;
            return lighthouse(url, opts, config).then(results => chrome.kill().then(() => results.lhr));
        });

ChrisDobby

import React from "react";

function WidthAndHeight() {
    const [width, setWidth] = React.useState(window.innerWidth);
    const [height, setHeight] = React.useState(window.innerHeight);

    React.useEffect(() => {
        window.addEventListener("resize", updateWidthAndHeight);
        return () => window.removeEventListener("resize", updateWidthAndHeight);
    });

ChrisDobby

import React from "react";

const scaleWidth = 500;
const scaleHeight = 500;

function draw(canvas, scaleX, scaleY) {
    const context = canvas.getContext("2d");
    context.scale(scaleX, scaleY);
    context.clearRect(0, 0, canvas.clientWidth, canvas.clientHeight);

ChrisDobby

import * as React from "react";

function HookRef() {
    const divRef = React.useRef<HTMLDivElement>(null);

    React.useEffect(() => {
        if (divRef.current) {
            console.log(`hookRef div width: ${divRef.current.clientWidth}`);
        }
    }, []);

ChrisDobby

import * as React from "react";

class CreateRef extends React.Component {
    divRef = React.createRef<HTMLDivElement>();

    componentDidMount() {
        if (this.divRef.current) {
            console.log(`createRefRef div width: ${this.divRef.current.clientWidth}`);
        }
    }

ChrisDobby

import * as React from "react";

class CallbackRef extends React.Component {
    divRef: HTMLDivElement | null = null;

    setDivRef = (element: HTMLDivElement) => {
        this.divRef = element;
    };

    componentDidMount() {

ChrisDobby

import * as React from "react";

const Forward = React.forwardRef((props, ref: React.Ref<HTMLDivElement>) => (
    <div ref={ref} style={{ width: "100%", height: "30px", backgroundColor: "green" }} />
));

function ForwardRef() {
    const divRef = React.useRef<HTMLDivElement>(null);

    React.useEffect(() => {

ChrisDobby

function evenWord(word) {
    let charCounts = [...word].reduce(
        (charCount, char) => ({
            ...charCount,
            [char]: charCount[char] ? charCount[char] + 1 : 1,
        }),
        {},
    );
    return Object.entries(charCounts).filter(([_, count]) => count % 2 !== 0).length;
}