nodejs throw er; // Unhandled 'error' event - node.js

Question

I made following, to play a bit around with node.js.
The files in the folder zipfiles are zipped accordingly and everything seems to work.
But I got an error on the cmd and I don't know where it comes from or how to solve it.
events.js:72
throw er; // Unhandled 'error' event
^
Error: write after end
at writeAfterEnd (_stream_writable.js:130:12)
at Gzip.Writable.write (_stream_writable.js:178:5)
at write (_stream_readable.js:583:24)
at flow (_stream_readable.js:592:7)
at ReadStream.pipeOnReadable (_stream_readable.js:624:5)
at ReadStream.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 ReadStream.Readable.push (_stream_readable.js:127:10)
Here's my script:
var zlib = require('zlib');
var gzip = zlib.createGzip();
var fs = require('fs');
var zip = {
zipAll: function(dir){
//files to zip
fs.readdir(dir, function(err, data){
if(err) throw(err);
var arrayValue = data.toString().split(',');
//files with .gz at the end, needs to be excluded
for(var i=0; i<arrayValue.length; i+=1){
console.log("Zipping following files: " + arrayValue[i]);
var input = fs.createReadStream('zipfiles/' + arrayValue[i]);
var output = fs.createWriteStream('zipfiles/input'+[i]+'.txt'+'.gz');
input.pipe(gzip).pipe(output);
}
});
}
};
zip.zipAll('zipfiles');
Thanks

Answer 1

The Gzip object is a bit wonky (afaik undocumented) to reuse for multiple files. The easiest way to fix your problem is to simply use a separate gzip object per file to compress, something like;
for(var i=0; i<arrayValue.length; i+=1){
console.log("Zipping following files: " + arrayValue[i]);
var input = fs.createReadStream('zipfiles/' + arrayValue[i]);
var output = fs.createWriteStream('zipfiles/input'+[i]+'.txt'+'.gz');
input.pipe(zlib.createGzip()).pipe(output);
}