Om4ar

Here's how you could create custom error classes in Node.js using latest ES6 / ES2015 syntax.

I've tried to make it as lean and unobtrusive as possible.

Defining our own base class for errors

errors/AppError.js

ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:
ffmpeg -i input.mp3 output.wma

You can get the list of supported formats with:
ffmpeg -formats

Convert WAV to MP3, mix down to mono (use 1 audio channel), set bit rate to 64 kbps and sample rate to 22050 Hz:

Shortcut — Action

CTRL + A — Move to the beginning of the line
CTRL + E — Move to the end of the line
CTRL + [left arrow] — Move one word backward (on some systems this is ALT + B)
CTRL + [right arrow] — Move one word forward (on some systems this is ALT + F)
CTRL + U — (bash) Clear the characters on the line before the current cursor position
CTRL + U —(zsh) If you're using the zsh, this will clear the entire line
CTRL + K — Clear the characters on the line after the current cursor position
ESC + [backspace] — Delete the word in front of the cursor

A quick overview of the node.js streams interface with basic examples.

This is based on @brycebaril's presentation, Node.js Streams2 Demystified

Overview

Streams are a first-class construct in Node.js for handling data.

Think of them as as lazy evaluation applied to data.

MySQL

Getting started

Laravel's Dependency Injection Container in Depth

Translations: Korean (by Yongwoo Lee)

Laravel has a powerful Inversion of Control (IoC) / Dependency Injection (DI) Container. Unfortunately the official documentation doesn't cover all of the available functionality, so I decided to experiment with it and document it for myself. The following is based on Laravel 5.4.26 - other versions may vary.

Introduction to Dependency Injection

I won't attempt to explain the principles behind DI / IoC here - if you're not familiar with them you might want to read What is Dependency Injection? by Fabien Potencier (creator of the Symfony framework).

	'use strict';

	// The purpose of this example is to show
	// how you can block the event loop with JavaScript.
	// There is 3 routes
	// / respond with Hello, World text
	// /block uses JavaScript while for 5 seconds
	// /non-block uses setTimeout for 5 seconds

	// Do the following

	{
	"version": "0.2.0",
	"configurations": [
	{
	"name": "Node Inspector",
	"type": "node",
	"request": "launch",
	"args": ["${workspaceRoot}/src/service.ts"],
	"runtimeArgs": ["-r", "ts-node/register"],
	"cwd": "${workspaceRoot}",

	const Benchmark = require('benchmark');
	const axios = require('axios');
	const superagent = require('superagent');

	var suite = new Benchmark.Suite;

	const targetUrl = 'http://httpbin.org/ip';

	suite
	.add('axios', {

	#/bin/sh
	ffmpeg -i input -c:v libx264 -preset slow -profile:v high -crf 18 -coder 1 -pix_fmt yuv420p -movflags +faststart -g 30 -bf 2 -c:a aac -b:a 384k -profile:a aac_low output