get progress of fetch()

fetchProgress.js

async function newguy(){

let response = await fetch('https://api.github.com/repos/javascript-tutorial/en.javascript.info/commits?per_page=100');

const reader = response.body.getReader();

// Step 2: get total length
const contentLength = +response.headers.get('Content-Length');

// Step 3: read the data
let receivedLength = 0; // received that many bytes at the moment
let chunks = []; // array of received binary chunks (comprises the body)
while(true) {
  const {done, value} = await reader.read();

  if (done) {
    break;
  }

  chunks.push(value);
  receivedLength += value.length;

  console.log(`Received ${receivedLength} of ${contentLength}`)
}

// Step 4: concatenate chunks into single Uint8Array
let chunksAll = new Uint8Array(receivedLength); // (4.1)
let position = 0;
for(let chunk of chunks) {
  chunksAll.set(chunk, position); // (4.2)
  position += chunk.length;
}

// Step 5: decode into a string
let result = new TextDecoder("utf-8").decode(chunksAll);

// We're done!
let commits = JSON.parse(result);
return commits
}
newguy().then(commits=>alert(commits[0].author.login))