artesanias/node_modules/got/source/get-response.js

'use strict';
const decompressResponse = require('decompress-response');
const is = require('@sindresorhus/is');
const mimicResponse = require('mimic-response');
const progress = require('./progress');

module.exports = (response, options, emitter) => {
	const downloadBodySize = Number(response.headers['content-length']) || null;

	const progressStream = progress.download(response, emitter, downloadBodySize);

	mimicResponse(response, progressStream);

	const newResponse = options.decompress === true &&
		is.function(decompressResponse) &&
		options.method !== 'HEAD' ? decompressResponse(progressStream) : progressStream;

	if (!options.decompress && ['gzip', 'deflate'].includes(response.headers['content-encoding'])) {
		options.encoding = null;
	}

	emitter.emit('response', newResponse);

	emitter.emit('downloadProgress', {
		percent: 0,
		transferred: 0,
		total: downloadBodySize
	});

	response.pipe(progressStream);
};