Resumable Upload Google Drive Api - Node Js

resumableUpload.js

var fs = require('fs');
var request = require('request');
var EventEmitter = require('events').EventEmitter;
var mime = require('mime');
var util = require('util');

function resumableUpload() {
	this.byteCount = 0; //init variables
	this.tokens = {};
	this.filepath = '';
	this.metadata = {};
	this.query = '';
	this.retry = -1;
	this.host = 'www.googleapis.com';
	this.api = '/upload/drive/v3/files';
};

util.inherits(resumableUpload, EventEmitter);

//Init the upload by POSTing google for an upload URL (saved to self.location)
resumableUpload.prototype.upload = function () {
	var self = this;
	var options = {
		url: 'https://' + self.host + self.api + '?uploadType=resumable' + self.query,
		headers: {
			'Host': self.host,
			'Authorization': 'Bearer ' + self.tokens.access_token,
			'Content-Length': new Buffer(JSON.stringify(self.metadata)).length,
			'Content-Type': 'application/json',
			'X-Upload-Content-Length': fs.statSync(self.filepath).size,
			'X-Upload-Content-Type': mime.getType(self.filepath)
		},
		body: JSON.stringify(self.metadata)
	};
	//Send request and start upload if success
	request.post(options, function (err, res, body) {
		if (err || !res.headers.location) {
			self.emit('error', new Error(err));
			self.emit('progress', 'Retrying ...');
			if ((self.retry > 0) || (self.retry <= -1)) {
				self.retry--;
				self.upload(); // retry
			} else {
				return;
			}
		}
		self.location = res.headers.location;
		self.send();
	});
}

//Pipes uploadPipe to self.location (Google's Location header)
resumableUpload.prototype.send = function () {
	var self = this;
	var options = {
		url: self.location, //self.location becomes the Google-provided URL to PUT to
		headers: {
			'Authorization': 'Bearer ' + self.tokens.access_token,
			'Content-Length': fs.statSync(self.filepath).size - self.byteCount,
			'Content-Type': mime.getType(self.filepath)
		}
	};
	try {
		//creates file stream, pipes it to self.location
		var uploadPipe = fs.createReadStream(self.filepath, {
			start: self.byteCount,
			end: fs.statSync(self.filepath).size
		});
	} catch (e) {
		self.emit('error', new Error(e));
		return;
	}
	var health = setInterval(function () {
		self.getProgress(function (err, res, body) {
			if (!err && typeof res.headers.range !== 'undefined') {
				self.emit('progress', res.headers.range.substring(8));
			}
		});
	}, 5000);
	uploadPipe.pipe(request.put(options, function (error, response, body) {
		clearInterval(health);
		if (!error) {
			self.emit('success', body);
			return;
		}
		self.emit('error', new Error(error));
		if ((self.retry > 0) || (self.retry <= -1)) {
			self.retry--;
			self.getProgress(function (err, res, b) {
				if (typeof res.headers.range !== 'undefined') {
					self.byteCount = res.headers.range.substring(8); //parse response
				} else {
					self.byteCount = 0;
				}
				self.send();
			});
		}
	}));
}

resumableUpload.prototype.getProgress = function (handler) {
	var self = this;
	var options = {
		url: self.location,
		headers: {
			'Authorization': 'Bearer ' + self.tokens.access_token,
			'Content-Length': 0,
			'Content-Range': 'bytes */' + fs.statSync(self.filepath).size
		}
	};
	request.put(options, handler);
}

module.exports = resumableUpload;

usage.js

var ResumableUpload = require('./resumableUpload');

module.exports = function (client, folderId, cb) {

	var resumableUpload = new ResumableUpload(); //create new ResumableUpload
	resumableUpload.tokens = client; //Google OAuth2 tokens
	resumableUpload.filepath = './pdf.pdf';
	resumableUpload.metadata = {
		name: 'pdf.pdf',
		parents: [folderId]
	};
	resumableUpload.query = '&supportsTeamDrives=true';
	resumableUpload.retry = 3; // Maximum retries when upload failed.
	resumableUpload.upload();
	resumableUpload.on('progress', function (progress) {
		console.log(progress);
	});
	resumableUpload.on('success', function (success) {
		cb(success)
	});
	resumableUpload.on('error', function (error) {
		console.log(error);
	});

};