How to convert string into binary buffer? - node.js

Question

I have two pieces of code:
var mmmagic = require('mmmagic');
var request = require('request');
var magic = new mmmagic.Magic(mmmagic.MAGIC_MIME_TYPE);
data = fs.readFileSync('/Users/myaccount/Desktop/test.png');
magic.detect(data,function(err,mime){
console.log(mime); // prints 'image/png'
}
and
var mmmagic = require('mmmagic');
var request = require('request');
var magic = new mmmagic.Magic(mmmagic.MAGIC_MIME_TYPE);
request.get('https://www.google.pl/images/srpr/logo11w.png',function(err,res,data){
data = new Buffer(data); // tried also new Buffer(data,'binary');
magic.detect(data,function(err,mime){
console.log(mime); // prints 'application/octet-stream'
}
})
So first one checks mime type of file from local disk and its 'image/png'.
The second one downloads image from url (its google logo in png format) from url and check its mime type and it is 'application/octet-stream'.
How I can convert response from request (which is a string) to a binary buffer so mime detection would return 'image/png'??

Answer 1

You have to pass in the option encoding: null
var mmmagic = require('mmmagic')
, request = require('request')
, magic = new mmmagic.Magic(mmmagic.MAGIC_MIME_TYPE)
, image = 'https://www.google.pl/images/srpr/logo11w.png';
request({
uri: image,
encoding: null
}, function(err, res, data) {
console.log(typeof data);
console.log(data.constructor);
magic.detect(data, function(err,mime) {
console.log(mime); // prints 'image/png'
});
});
I noticed that data was a string when using request.get(<urlString>). For debugging purposes I used typeof <something> & <something>.constructor to determine what <something> really was.
The docs are a little misleading stating that
encoding - Encoding to be used on setEncoding of response data. If null, the body is returned as a Buffer.
Making one think that the default would be a Buffer!