What's the equivalent of nodejs Buffer.from(buffer, "base64") in deno - deno

Question

I'm working on a database with blob data. I made use of deno MySQL to pull the record and want to return it as a base64. In nodejs there's this Buffer.from(<buffer data>, "base64") then to print the base64 value do .toString().
How can I do this using Deno? I've been reading a lot about base64 encoder and some third-party libraries but I can't find anything.
// import mysqlClient from "https://deno.land//x/mysql#v2.10.2/mod.ts"
// mysql configuration :w
// some configuration to connect to mysql
const [{pdf}] = await mysql.query("select pdf from files where ...")
const b64 = atob(pdf); // Invalid Charater
console.log(typeof b64); // String
Tried using nodej and I just have to do Buffer.from(pdf, "base64").toString(); and it returns the correct base64 string
Was able to fix the problem. Seems like the problem was the MySQL plugin. I tried using mysql2 (https://deno.land/x/mysql2#v1.0.6) and it's returning the correct datatype and was able to convert data to base64 with the answers given below.

Answer 1

The Deno standard lib provides functions to encode / decode base64 :
import { decode as base64Decode, encode as base64Encode } from 'https://deno.land/std#0.166.0/encoding/base64.ts'
import { assertEquals } from 'https://deno.land/std#0.166.0/testing/asserts.ts'
const value = 'Hello World!'
console.log('value :', value)
const encodedValue = base64Encode(value)
console.log('encodedValue :', encodedValue)
const decodedValue = new TextDecoder().decode(base64Decode(encodedValue))
console.log('decodedValue :', decodedValue)
assertEquals(decodedValue, value)