nkhil

Example of functional piping

  const pipeAsync = (...fns) => async (value) => {
    console.log('fns', fns)
    return await fns.reduce((sum, fn) => {
      if (typeof fn !== 'function') {
        throw new TypeError('fn is not a function');
      }
 return Promise.resolve(sum).then(fn);

nkhil

const transactions = [
  {
    merchantName: 'Netflix',
    amount: 5.99,
    currency: 'GBP',
    bookingDateTime: '2020-01-01T19:33:23.473Z',
  },
  {
    merchantName: 'Petfood Co',

nkhil

const albums = [
  {
    artist: "Pearl Jam",
    album: "Ten",
    year: "1991"
  },
  {
    artist: "Pearl Jam",
    album: "Yield",
    year: "1998"

nkhil

{
    1991: [
      {
        {
          artist: 'Pearl Jam',
          album: 'Ten',
          year: '1991',
        },
        {
          artist: 'Soundgarden',

nkhil

{
    'Pearl Jam': [
      {
        artist: 'Pearl Jam',
        album: 'Ten',
        year: '1991',
      },
      {
        artist: 'Pearl Jam',
        album: 'Yield',

nkhil

function groupBy(key) {
  return function group(array) {
    return array.reduce((acc, obj) => {
      const property = obj[key];
      acc[property] = acc[property] || [];
      acc[property].push(obj);
      return acc;
    }, {});
  };
}

nkhil

const property = obj[key];
// obj[key] here will be '1991'.

acc[property] = acc[property] || [];
// At this point acc['1991'] doesn't yet exist, so it will be an empty array. This step is important as it checks if acc['1991'] exists, and if not, creates it and assigns a value of an empty array.

acc[property].push(obj);
// Here, all we're doing is pushing our object into the right group

nkhil

MongoDB Cheat Sheet

Show All Databases

show dbs

Show Current Database

nkhil

{
    "window.zoomLevel": 0,
    "terminal.integrated.shell.osx": "zsh",
    "editor.fontFamily": "Fira Code",
    "editor.fontLigatures": true,
    "editor.minimap.enabled": false,
    "workbench.iconTheme": "material-icon-theme",
    "workbench.editor.enablePreview": false,
    "editor.tabSize": 2,
    "editor.rulers": [100],

nkhil

Quick reference for using node-scheduler

Every 5 seconds

const x = schedule.scheduleJob('*/5 * * * * *', function() {
  console.log('The answer to life, the universe, and everything!');
});