Throws encoding error when used with readSync

[ysobolev]

The following code throws an exception in node v6.x (and earlier):

Buffer = require('buffer/').Buffer;
buff = Buffer(13);
fd = fs.openSync('./test', 'r');
fs.readSync(fd, buff, 0, 13);

The reason is that in fs.js in the node distribution, the readSync() function contains:

  if (!(buffer instanceof Buffer)) {
    // legacy string interface (fd, length, position, encoding, callback)

See https://github.com/nodejs/node/blob/v6.x/lib/fs.js#L705

As a result, the function thinks it is being passed a string and the length ends up being passed in as the encoding.

I realize this is fixed in later version of node per your issue: nodejs/node#4530

Are there plans to allow this Buffer implemenation to work with the read calls in node v6?

[feross]

Is there a particular reason that you're using this buffer implementation in Node.js?

I don't recommend passing this Buffer implementation into functions from Node.js core packages, like fs. These buffer instances will not be treated as real Node.js buffers because they fail a instanceof Buffer check. Things still might work out, since they're still a subclass of Uint8Array and they have a length property (so they're array-like), but instanceof won't ever work.

Let me know what problem you're trying to solve, and perhaps I can suggest a solution for your needs?