_readableState is private, use byteCount

[robertrossmann]

Fixes #1

[lukasredev]

It's strange: If I use the module in my own project byteCount is working fine, but when running the sails-adapter-tests byteCount seems to be undefined. This was the reason why I changed it to _readableState.length, because it seems to be always working ...

[robertrossmann]

I could try having a look at those tests... I suspect that the _readableState only represents the part of the upload that is immediately available for processing, which may or may not be the whole dataset.

Further reading at IO.js (should apply to Node.js, too).

[robertrossmann]

The byteCount property comes from multiparty, the body parser that Skipper uses internally. It is then quite likely that the property is not set when doing some test mockups.

On a side note, I wonder why Azure requires explicit content-length... None of the other "big guys", S3, GridFS, or Google Cloud Storage adapters need to provide this. Could there perhaps be a different way of uploading files to Azure without having to know the content-length in advance?

[lukasredev]

Ok thanks for the information.
Yes this seemed kind of weird to me either. Maybe you could open an issue or write someone on the azure-storage project?