Intermittent uncaught error from gaze

[callumlocke]

I'm getting this error a lot while using gaze to watch a directory, and using Sublime Text 3 (on OS X Mountain Lion) to edit files in that directory. About 1 in every 5 saves causes my Node process to exit with this error:

Error: ENOENT, no such file or directory '/Users/callum.locke/code/ft/ft/manual/exp2-app/.subl38b.tmp'
  at Object.fs.lstatSync (fs.js:679:18)
  at /Users/callum.locke/code/exp/node_modules/gaze/lib/gaze.js:270:21
  at iterate (/Users/callum.locke/code/exp/node_modules/gaze/lib/helper.js:106:5)
  at Object.forEachSeries (/Users/callum.locke/code/exp/node_modules/gaze/lib/helper.js:121:3)
  at /Users/callum.locke/code/exp/node_modules/gaze/lib/gaze.js:267:12
  at ReaddirReq.Req.done (/Users/callum.locke/code/exp/node_modules/gaze/node_modules/graceful-fs/graceful-fs.js:143:5)
  at ReaddirReq.done (/Users/callum.locke/code/exp/node_modules/gaze/node_modules/graceful-fs/graceful-fs.js:90:22)
  at ReaddirReq.Req.done (/Users/callum.locke/code/ft/web/node_modules/graceful-fs/graceful-fs.js:143:5)
  at ReaddirReq.done (/Users/callum.locke/code/ft/web/node_modules/graceful-fs/graceful-fs.js:90:22)
  at Object.oncomplete (fs.js:107:15)

The problem is lines 270-271 in lib/gaze.js:

if (!fs.existsSync(filepath)) return next();
var stat = fs.lstatSync(filepath); // this line occasionally throws an ENOENT error

I think this is probably due to this thing explained in the Node docs for fs.exists:

fs.exists() is an anachronism and exists only for historical reasons. There should almost never be a reason to use it in your own code.

In particular, checking if a file exists before opening it is an anti-pattern that leaves you vulnerable to race conditions: another process may remove the file between the calls to fs.exists() and fs.open(). Just open the file and handle the error when it's not there.