adeleke5140

function debounce(func, wait){
  let timer;
  
  let debouncedFunc = function(...args){
    clearTimeout(timer)
    
    timer = setTimeout(() => {
    	func.apply(this, args)
    }, wait)
  }

adeleke5140

//conditionally add properties in a typesafe way

declare let hasMiddle: boolean

const fullName = { first: 'Kehinde', last: 'Adeleke'}
//the issue
const developer2 = {...fullName}

//if you tried adding a new key,
//typescript would scream that middle does not exist on type { first: string, last: string}

adeleke5140

Type Narrowing

A way to help typescript narrow your types is by explicitly adding a tag to them. This helps in narrowing the type when necessary.

adeleke5140

const _cache: {[url: string]:string} = {}

async function fetchWithCache(url:string){
	if(url in cache){
  	return _cache[url]
  }
  
  const response = await fetch(url)
  const text = response.text()
  _cache[url] = text

adeleke5140

.backdrop {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  background: #000000e1;
  display: flex;
  align-items: center;
  justify-content: center;

adeleke5140

<form
  action="/api/search"
  method="post"
  onSubmit={event => {
    event.preventDefault();

    fetch(
      '/api/search',
      {
        method: 'POST',

adeleke5140

import Grid from './Grid'

function App(){
  return (
    <Grid numRows={2} numCols={4}/>
    )
}

export default App

adeleke5140

import { useState, useEffect } from "react";

const useLocalStorage = (key: string, initialValue: any) => {
  const isServer = typeof window === "undefined";

  const [value, setValue] = useState(() => {
    if (isServer) {
      return initialValue;
    }

adeleke5140

const cons = (x, y) => (m) => m(x, y)

const car = (z) => z((p, q) => p)

const cdr = (z) => z((p, q) => q)


const someLinkedList = cons(1, cons(2, cons(3 , null)))

// iterating

adeleke5140

import * as esbuild from 'esbuild-wasm'
import axios from 'axios'

export const unpkgPathPlugin = () => {
    return {
        name: 'unpkg-path-plugin',
        setup(build: esbuild.PluginBuild) {
            build.onResolve({ filter: /.*/ }, async (args) => {
                console.log('onResolve', args)
                if(args.path === 'index.js'){