Real Nodejs, No need for libraries, no need to code these yourself!

Wednesday, 02/11/2022

Tram Ho

When faced with a problem, many of you often look for a library to solve that problem or develop your own. Using the library is like a double-edged sword. It helps to solve the problem quickly but makes the project heavier. Self-development takes a lot of work. In this small blog I list some cases where we don’t need a library, don’t need to code ourselves because nodejs already supports it.

1. Gen UUID v4.

UUID – (universally unique identifier) is interpreted as a unique identification id 128bit long. UUIDs are very commonly used when you need a unique id for the system. UUID v4 is the most commonly used, random uuid type.

1.1 Some support libraries:

uuid :

<span class="token keyword">const</span> uuid <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'uuid'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">Here is a test v4 uuid: </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> uuid <span class="token punctuation">.</span> <span class="token function">v4</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

const uuid = require ( 'uuid' ) ;

console . log ( ` Here is a test v4 uuid: ${ uuid . v4 ( ) } ` ) ;

nano ID :

<span class="token keyword">const</span> Nanoid <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'nanoid'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token keyword">const</span> NanoidAsync <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'nanoid/async'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">UUID with Nano ID sync: </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> Nanoid <span class="token punctuation">.</span> <span class="token function">nanoid</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token punctuation">(</span> <span class="token keyword">async</span> <span class="token keyword">function</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
  <span class="token keyword">const</span> nanoId <span class="token operator">=</span> <span class="token keyword">await</span> NanoidAsync <span class="token punctuation">.</span> <span class="token function">nanoid</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
  console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">UUID with Nano ID async: </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> nanoId <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span> <span class="token punctuation">)</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

const Nanoid = require ( 'nanoid' ) ;

const NanoidAsync = require ( 'nanoid/async' ) ;

console . log ( ` UUID with Nano ID sync: ${ Nanoid . nanoid ( ) } ` ) ;

( async function ( ) {

const nanoId = await NanoidAsync . nanoid ( ) ;

console . log ( ` UUID with Nano ID async: ${ nanoId } ` ) ;

} ) ( ) ;

1.2 Don’t use libraries:

cryto module added in nodejs v14.17.0. It has provided many methods to support encryption: HMAC, cypher, OpenSSL and also randomUUID to generate UUID.

<span class="token keyword">const</span> crypto <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'crypto'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> crypto <span class="token punctuation">.</span> <span class="token function">randomUUID</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

const crypto = require ( 'crypto' ) ;

console . log ( crypto . randomUUID ( ) ) ;

2. Objects deep comparison

Objects deep comparison is a type of sâu comparison of two objects. Compares two objects that are 100% identical, including nested objects. Need to separate from type:

Shadow comparison: Shallow comparison: Compare the list of Object.keys properties and compare the values of the properties.
Referential comprison: Compares to references of variables. Because objects are reference type variables.

2.1 Using the defense:

lodash _isEqual

var object = { 'a': 1 };
var other = { 'a': 1 };
 
_.isEqual(object, other);
// =&gt; true
 
object === other;
// =&gt; false

var object = { 'a': 1 };

var other = { 'a': 1 };

_.isEqual(object, other);

// => true

object === other;

// => false

2.2 Using JSON.stringify:

Convert the object to json and then compare it like comparing two strings.

<span class="token constant">JSON</span> <span class="token punctuation">.</span> <span class="token function">stringify</span> <span class="token punctuation">(</span> object1 <span class="token punctuation">)</span> <span class="token operator">===</span> <span class="token constant">JSON</span> <span class="token punctuation">.</span> <span class="token function">stringify</span> <span class="token punctuation">(</span> object2 <span class="token punctuation">)</span>

JSON . stringify ( object1 ) === JSON . stringify ( object2 )

Isues: Is to fail when comparing similar objects as keys out of order:

obj1 <span class="token operator">=</span> <span class="token punctuation">{</span> a <span class="token operator">:</span> <span class="token number">2</span> <span class="token punctuation">,</span> b <span class="token operator">:</span> <span class="token number">4</span> <span class="token punctuation">}</span> <span class="token punctuation">;</span>
obj2 <span class="token operator">=</span> <span class="token punctuation">{</span> b <span class="token operator">:</span> <span class="token number">4</span> <span class="token punctuation">,</span> a <span class="token operator">:</span> <span class="token number">2</span> <span class="token punctuation">}</span> <span class="token punctuation">;</span>
<span class="token constant">JSON</span> <span class="token punctuation">.</span> <span class="token function">stringify</span> <span class="token punctuation">(</span> obj1 <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// "{"a":2,"b":4}"</span>
<span class="token constant">JSON</span> <span class="token punctuation">.</span> <span class="token function">stringify</span> <span class="token punctuation">(</span> obj2 <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// "{"b":4,"a":2}"</span>

obj1 = { a : 2 , b : 4 } ;

obj2 = { b : 4 , a : 2 } ;

2.3 Don’t use libraries, use util.isDeepStrictEqual

Util modules is a nodejs library that provides developers with many commonly used methods. isDeepStrictEqual is a method to compare two objects:

util <span class="token punctuation">.</span> <span class="token function">isDeepStrictEqual</span> <span class="token punctuation">(</span> val1 <span class="token punctuation">,</span> val2 <span class="token punctuation">)</span>

1 2	util <span class="token punctuation">.</span> <span class="token function">isDeepStrictEqual</span> <span class="token punctuation">(</span> val1 <span class="token punctuation">,</span> val2 <span class="token punctuation">)</span>

3. Extract domain name from URL

Extract domain is what I need to get the information of a domain such as, subdomain, domain, port.

3.1 using extract-domain library

<span class="token keyword">import</span> extractDomain <span class="token keyword">from</span> <span class="token string">"extract-domain"</span> <span class="token punctuation">;</span>
<span class="token keyword">const</span> url <span class="token operator">=</span> <span class="token string">"https://www.npmjs.com/package/extract-domain"</span> <span class="token punctuation">;</span>
<span class="token function">extractDomain</span> <span class="token punctuation">(</span> url <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// npmjs.com</span>

import extractDomain from "extract-domain" ;

const url = "https://www.npmjs.com/package/extract-domain" ;

extractDomain ( url ) ; // npmjs.com

3.2 Using URL modules

<span class="token keyword">var</span> url <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">URL</span> <span class="token punctuation">(</span> urlString <span class="token punctuation">)</span> <span class="token punctuation">;</span>
console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> url <span class="token punctuation">.</span> hostname <span class="token punctuation">)</span> <span class="token punctuation">;</span>

var url = new URL ( urlString ) ;

console . log ( url . hostname ) ;

4. API check heath.

In a microservice system, sometimes services need ONE api for the system to call to check if a service is alive (To be able to restart).

4.1 Using express

<span class="token keyword">const</span> express <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'express'</span> <span class="token punctuation">)</span>
<span class="token keyword">const</span> app <span class="token operator">=</span> <span class="token function">express</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>

app <span class="token punctuation">.</span> <span class="token function">get</span> <span class="token punctuation">(</span> <span class="token string">'/'</span> <span class="token punctuation">,</span> <span class="token keyword">function</span> <span class="token punctuation">(</span> <span class="token parameter">req <span class="token punctuation">,</span> res</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
  res <span class="token punctuation">.</span> <span class="token function">send</span> <span class="token punctuation">(</span> <span class="token string">'Server is up!'</span> <span class="token punctuation">)</span>
<span class="token punctuation">}</span> <span class="token punctuation">)</span>

app <span class="token punctuation">.</span> <span class="token function">listen</span> <span class="token punctuation">(</span> <span class="token number">3000</span> <span class="token punctuation">)</span>

const express = require ( 'express' )

const app = express ( )

app . get ( '/' , function ( req , res ) {

res . send ( 'Server is up!' )

} )

app . listen ( 3000 )

Many other framework libraries.

4.2 Don’t use real, use http module

<span class="token keyword">const</span> http <span class="token operator">=</span> <span class="token function">require</span> <span class="token punctuation">(</span> <span class="token string">'http'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token keyword">const</span> <span class="token function-variable function">requestListener</span> <span class="token operator">=</span> <span class="token keyword">function</span> <span class="token punctuation">(</span> <span class="token parameter">req <span class="token punctuation">,</span> res</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
  res <span class="token punctuation">.</span> <span class="token function">writeHead</span> <span class="token punctuation">(</span> <span class="token number">201</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
  res <span class="token punctuation">.</span> <span class="token function">end</span> <span class="token punctuation">(</span> <span class="token string">'Server is up!'</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">const</span> server <span class="token operator">=</span> http <span class="token punctuation">.</span> <span class="token function">createServer</span> <span class="token punctuation">(</span> requestListener <span class="token punctuation">)</span> <span class="token punctuation">;</span>
server <span class="token punctuation">.</span> <span class="token function">listen</span> <span class="token punctuation">(</span> <span class="token number">8080</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

const http = require ( 'http' ) ;

const requestListener = function ( req , res ) {

res . writeHead ( 201 ) ;

res . end ( 'Server is up!' ) ;

}

const server = http . createServer ( requestListener ) ;

server . listen ( 8080 ) ;

5. Conclusion:

Sometimes paying a little attention to research helps our system become lighter.
Thank you everyone for reading
Many of you have had a similar case, comment for everyone to know. Happy sharing!!

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Source : Viblo