file watching doesn't work as expected on Windows

[heycalmdown]

fs.watch on Windows lies on below function:
https://github.com/joyent/libuv/blob/95e89c6a0efec2d2228377cfdf55cd14b1b83536/src/win/fs-event.c#L69

as you can see on the fourth option(FALSE) it doesn't watch any changes of subtree's.

I suggest use the same function - watchFile - as used for non-win32 implements.

[iangreenleaf]

Do you mean it's no longer recursively watching everything in a directory? It was working at some point - we couldn't always get the exact filename that had changed, but could at least detect change events.

I would like to unify the system calls. I'm hesitant though because as noted in nodejs/node-v0.x-archive#2049, it's not totally clear which option is preferred - the core guys stated at one point that watchFile will be going away, and the docs instruct you to use watch when available. But watch still has some bugs and doesn't always pass a filename, which would be a problem for a couple of our features. And just to compound matters, it's unclear from the docs if watchFile makes use of inotify etc when available, or if it is a purely polling solution (at one point it was using inotify, but maybe that's only happening in watch now).

So my point is that neither of the options looks totally great to me right now. Thoughts?

[heycalmdown]

As you know node-supervisor watch the root directory only via fs.watch on Windows. And according to the implement of the fs.watch the fourth option is FALSE that means ReadDirectoryChangesW doesn't watch files recursively at all.
http://msdn.microsoft.com/en-us/library/windows/desktop/aa365465(v=vs.85).aspx

Not just leaking exact filename, but leaking the event too.

I can understand why the implementation of fs.watch use the option, because making too big size of buffer for watch huge number of files leads to get the BSOD. And also understand your concern about polling many files with fs.watchFile.

So here is my thought: seek directories recursively like non-windows implementation and watch directory only not each files.

pseudo code:

var findAllWatchFiles = function(dir, callback) {
  dir = path.resolve(dir);
  if (ignoredPaths[dir])
    return;
  fs.stat(dir, function(err, stats){
    if (err) {
      util.error('Error retrieving stats for file: ' + dir);
    } else {
      if (stats.isDirectory()) {
        if (isWindows) callback(dir);
        fs.readdir(dir, function(err, fileNames) {
          if(err) {
            util.error('Error reading path: ' + dir);
          }
          else {
            fileNames.forEach(function (fileName) {
              findAllWatchFiles(dir + '/' + fileName, callback);
            });
          }
        });
      } else {
        if (!isWindows && dir.match(fileExtensionPattern)) {
          callback(dir);
        }
      }
    }
  });
};

[iangreenleaf]

Closed by #70.