mbchoa

function composeProviders(providers) {
  return providers.reduce((AccumulatedProviders, [Provider, props = {}]) => {
    return ({ children }) => (
      <AccumulatedProviders>
        <Provider {...props}>{children}</Provider>
      </AccumulatedProviders>
    );
  }, ({ children }) => <>{children}</>);
}

mbchoa

select t.*
from table t
join
    (
        select column_with_dupes
        from table
        group by column_with_dupes
        having count(column_with_dupes) > 1
    ) using (column_with_dupes)

mbchoa

function findNumberCombinations(numbers, target) {
  const result = [];

  function backtrack(index, currentCombination, currentSum) {
    if (currentSum === target) {
      result.push([...currentCombination]);
      return;
    }

    if (currentSum > target || index >= numbers.length) {

mbchoa

Linking a custom domain to a deployed application is confusing and at times you don't get a route on how to link the domain with the website. 😫

In this article, I will be explaining how to link a Custom domain brought in Google Domains service to an application hosted on Vercel.

Perks of using vercel is that it allows adding domain without any verification unlike Heroku/Netlify, which means you don't have to add your billing details to add a domain to your application. Moreover, it is fast, efficient, and easy to use.😁

What is Vercel?

​Vercel is a deployment and collaboration platform for frontend developers. ​Vercel enables developers to host websites and web services that deploy instantly and scale automatically – all without any configuration. Source - Official Docs

mbchoa

export const jsonToCsv = (json, filename: string) => {
  const replacer = (key, value) => (value === null ? "" : value);
  const header = Object.keys(json[0]);
  return [
    header.join(","),
    ...json.map((row) =>
      header
        .map((fieldName) => JSON.stringify(row[fieldName], replacer))
        .join(",")
    ),

mbchoa

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

mbchoa

import { useState, useRef } from 'react';

const useTimer = (initialState = 0) => {
  const [elapsedTime, setElapsedTime] = useState(initialState);
  const [isRunning, setIsRunning] = useState(false);
  const countRef = useRef(null);

  const handleStart = () => {
    const startTime = Date.now() - elapsedTime;
    countRef.current = setInterval(() => {

mbchoa

netstat -plten | grep LISTEN | grep <PORT>
kill -9 <PID>

mbchoa

function fill(el, numRepeat) {
  return [...Array(numRepeat)].map(() => el).join('');
}

mbchoa

const UNASSIGNED = -1;
const ASSIGNED = 1;

class Board {
  constructor(size, options) {
    this.board = [];
    this.size = size;
    this.options = options;

    for (let row = 0; row < size; row++) {