Error: EISDIR: illegal operation on a directory, fstat

[jtenner]

Hello! Great work on this project by the way.

In reference to #17 where the writes to stdout and stderr were returning 31.

Looks like

const stat = (wasi, fd) => {
  ...
  const stats = fs.fstatSync(entry.real);
  ...
};

Seems to be the trouble on windows. :)

When the file descriptor is 0, 1 or 2, it looks like an error code EISDIR is thrown because it's not an actual file descriptor on windows.

Perhaps there is a good way this can be fixed? I could help submit a pull request.

[devsnek]

If someone on windows wants to fix this I will gladly accept a PR.

Alternatively, a better solution might be to change fds 0, 1, and 2 to be streams, which would allow overriding them in the wasi constructor. This would also mean the defaults can be process.stdin and such so we wouldn't need to worry about platform specifics.