aneurysmjs

function upper(arr: string[]) {
  for (let i = 0; i < arr.length; i += 1) {
    let str = arr[i];
    console.log(str.upperCase())
  }
}

upper(['foo', 'bar', 'baz']);

// In Typescript when index into an array you get the element type of the array.

aneurysmjs

#!/usr/bin/env sh

# checks to see if running 
launchctl list | grep mongo
 
launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.mongodb.plist
launchctl remove homebrew.mxcl.mongodb

pkill -f mongod

aneurysmjs

function replaceRange(str: string, start: number, end: number, substitute: string): string {
  const chunk = substitute.repeat(end - start);
	
  return `${str.substring(0, start)${chunk}${str.substring(end)}`;
}

aneurysmjs

/**
 * match first character after white space
 */
const firstAtWhiteSpace = /(^|\s)[a-z]/g;

aneurysmjs

// in this case the state is each individual product
const product = (state, action) => {
  switch (action.type) {
    case 'CREATE_PRODUCT':
      return {
        id: action.id,
        name: action.name,
        price: action.price,
      };
    case 'EDIT_PRODUCT':

aneurysmjs

<!-- 
  even though the "blue" comes later in the list of classes,
  but CSS rules of precedence actually depends of the order of
  classes in the stylesheet
-->
<span class="red blue">
  so I'm red
</span>

aneurysmjs

ignore files temporarily

start ignoring changes to a file:

git update-index --assume-unchanged path/to/file

keep tracking again:

git update-index --no-assume-unchanged path/to/file

see here

get a list of files marked --assume-unchanged:

git ls-files -v | grep '^[[:lower:]]'

aneurysmjs

/**
 * @link this is taken from here for reference
 * https://github.com/testing-library/react-hooks-testing-library/issues/20#issuecomment-476628600
 */
import { useState, useEffect } from 'react';
import { renderHook } from '@testing-library/react-hooks';

describe('error hook tests', () => {
  function useError(obj: Error | string): boolean {
    if (obj.constructor.name === 'Error') {

aneurysmjs

// .babelrc
{
  "presets": [
    [
      "@babel/preset-env",
      { 
        // this tells @babel "hey, don'y change any of the modules, let Webpack handle it
        "modules": false
         // you only get the individual pollyfill that you need
         "useBuiltIns": "usage"

aneurysmjs

interface Base {
  id: string;
  timestamp: string;
}

interface Product extends Base {
  price: number;
  stock: number;
}