text: <!doctype html>
  <script>
  (async () {
  	
  	const response = await fetch('long.txt');
  	const reader = response.body.getReader();
  
  	const contentLength = +response.headers.get('Content-Length');
  	let receivedLength = 0;
  	let chunks = [];
  	while(true) {
  		const chunk = await reader.read();
  
  		if (chunk.done) {
  			console.log("done!");
  			break;
  		}
  
  		chunks.push(chunk.value);
  		receivedLength += chunk.value.length;
  		console.log(`${receivedLength}/${contentLength} received`)
  	}
  
  
  	let chunksMerged = new Uint8Array(receivedLength);
  	let length = 0;
  	for(let chunk of chunks) {
  		chunksMerged.set(chunk, length);
  		length += chunk.length;
  	}
  
  	let result = new TextDecoder("utf-8").decode(chunksMerged);
  	console.log(result);
  })();
  
  </script>
  