encoding is ignored in fs.readFile - node.js

Question

I am trying to read the contents of a properties file in node. this is my call:
fs.readFile("server/config.properties", {encoding: 'utf8'}, function(err, data ) {
console.log( data );
});
The console prints a buffer:
<Buffer 74 69 74 69 20 3d 20 74 6f 74 6f 0a 74 61 74 61 20 3d 20 74 75 74 75>
when I replace the code with this:
fs.readFile("server/config.properties", function(err, data ) {
console.log( data.toString('utf8') );
});
it works fine. But the node documentation says the String is converted to utf8 if the encoding is passed in the options
the output of node --version is v0.10.2
What am I missing here?
thank you for your support

Answer 1

Depending on the version of Node you're running, the argument may be just the encoding:
fs.readFile("server/config.properties", 'utf8', function(err, data ) {
console.log( data );
});
The 2nd argument changed to options with v0.10:
FS readFile(), writeFile(), appendFile() and their Sync counterparts now take an options object (but the old API, an encoding string, is still supported)
For former documentation:
v0.8.22
v0.6.21

Answer 2

You should change {encoding: 'utf8'} to {encoding: 'utf-8'}, for example:
fs.readFile("server/config.properties", {encoding: 'utf-8'}, function(err, data ) {
console.log( data );
});