Chunking stream into data chunks using Node.js - node.js

Question

I am trying to chunk a file into data chunks. I found that link does the job beautifully but when I use the above library in the following manner:
var in = fs.createReadStream(__dirname+'/try.html'),
chunker = new SizeChunker({
chunkSize: 2048
}),
output;
chunker.on('chunkStart', function(id, done) {
output = fs.createWriteStream('./output-' + id);
console.log("Chunkstart!");
console.log("Input: "+in.length);
done();
});
chunker.on('chunkEnd', function(id, done) {
output.end();
console.log("Chunkend!");
done();
});
chunker.on('data', function(dat) {
console.log("Writing chunk to output!")
output.write(dat.chunk);
console.log(dat.chunk);
});
input.pipe(chunker);
But I am getting this error :
_stream_writable.js:201
var len = state.objectMode ? 1 : chunk.length;
^
TypeError: Cannot read property 'length' of undefined
at writeOrBuffer (_stream_writable.js:201:41)
at WriteStream.Writable.write (_stream_writable.js:180:11)
at SizeChunker.<anonymous> (/Users/admin/Documents/chunk.js:16:15)
at SizeChunker.EventEmitter.emit (events.js:95:17)
at SizeChunker.<anonymous> (_stream_readable.js:746:14)
at SizeChunker.EventEmitter.emit (events.js:92:17)
at emitReadable_ (_stream_readable.js:408:10)
at emitReadable (_stream_readable.js:404:5)
at readableAddChunk (_stream_readable.js:165:9)
at SizeChunker.Readable.push (_stream_readable.js:127:10)
Also, in.length is undefined when displayed using console.log(). Can anyone please help me resolve this issue? Thanks in advance.

Answer 1

When you listen for data on the chunker stream, the dat argument has no property chunk. You can read on the chunking-stream readme the following:
Each data chunk is an object with the following fields:
id: number of chunk (starts from 1) data: Buffer with data
You can do something like this instead:
chunker.on('data', function(dat) {
console.log("Writing chunk to output!")
output.write(dat.data);
console.log(dat);
});
Also, in is a stream and has no length property defined.