We have a bunch of code in network that reads/writes to sockets or io-like objects (or even presents an io-like interface), e.g., noise::stream or version handshake. Since IO reads/writes can be fragmented (i.e., I write(&[1,2,3,4]) but it only writes the first 2 bytes), we want to make sure our logic handles this edge case. We also have some basic test utils like the various fake_socket's that support basic fragmented reads (it splits all reads into read 1 byte) from a fixed buffer, which probably catch most dumb mistakes. However, I think we can take a more systematic approach and use proptest to sample a sequence of Read(n)/Write(n) ops and use these to determine the sizes of each fragmented read/write.

Luckily, a useful crate just popped up on my radar that seems to do exactly this: https://github.com/facebookincubator/rust-partial-io

It needs some small work to support proptest instead of quickcheck, but otherwise looks good.

@gregnazario @mimoo