no error or return for pako inflate?

Hi there,

I’m trying to use pako for clientside decompression but for some reason the code doesn’t return the decompressed Uint8Array when using the inflate method. I also don’t see an error getting caught for some reason?

Any help would be great!

https://pakotest.baylyd.repl.co

[rlidwka]

Reproduction sample:

let zlib = require('zlib');
let pako = require('pako');

let sample = zlib.deflateSync(Buffer.from('foobar'));
let sample2 = Buffer.concat([ sample, Buffer.from([ 1 ]) ]);

console.log('zlib sample 1', zlib.inflateSync(sample));
// outputs <Buffer 66 6f 6f 62 61 72>

console.log('pako sample 1', pako.inflate(sample));
// outputs Uint8Array(6) [ 102, 111, 111, 98, 97, 114 ]

console.log('zlib sample 2', zlib.inflateSync(sample2));
// outputs <Buffer 66 6f 6f 62 61 72>

console.log('pako sample 2', pako.inflate(sample2));
// outputs undefined

[DevinBayly]

really? one extra byte made all the difference I suppose.

The length of the compressed data was something that I calculated using the first 4 bytes of the chunk header pasted again here but it’s entirely on me that there’s an off by one error in calculating the length of the compressed data.

So in a sense the extra byte in the binary file comes from me supplying one too many bytes probably by computing the length in bytes of the compressed data wrong with this code

function compute_chunk_size(hdr) {
  return hdr.reduce((acc, cur, i) => {
    // the header is 4 bytes so 0-3 are the i's
    return acc + (cur << (8 * (3 - i)));
  }, 0);
}

supplying the [0,0,15,131] as the hdr parameter above

I guess I shouldn’t expect pako to speak up in cases like this with an error thrown though.