Files created right before watching starts make watching go into a loop

I’ve noticed this strange behaviour where watcher loops for 10 seconds due to this code:

if(data) {
  var ts = data[0] === data[1] ? data[0] + FS_ACCURENCY : data[0];
  if(ts > startTime)
    watcher.emit("change", data[1] + FS_ACCURENCY);
}

https://github.com/webpack/watchpack/blob/7efdd93aff0c991a766af886ccc16324401a202f/lib/DirectoryWatcher.js#L202-L205

What I’m doing in my script is basically creating a file in a temporary directory /temp/entry.js, creating a webpack compiler and run compiler.watch(). Now for 10 seconds (which is the default value of FS_ACCURENCY) this is what’s happening:

• compilation succeeds
• Watching.prototype._done gets called
• recalling Watching.prototype.watch
• which immediately triggers a change event for the /temp/entry.js file, because it’s < 10 seconds old
• back to step 1

Any pointers on how to fix this would be helpful. For example, this could be fixed by modifying the above code to this, but I’d need to stare at this for longer to understand what this block of code is conceptually responsible for.

if(ts > startTime + FS_ACCURENCY) {

[yessky]

This issue also confused me for a while. finally I found a trick to fix it.

  const compiler = webpack(webpackConfig);
  const timefix = 11000;
  compiler.plugin('watch-run', (watching, callback) => {
    watching.startTime += timefix;
    callback()
  });
  compiler.plugin('done', (stats) => {
    stats.startTime -= timefix
  })

also a npm package is available https://github.com/yessky/webpack-mild-compile, it works with webpack v2/3/4.

[fenomas]

For anyone else tearing out hair over this, backdating the relevant files by ten seconds is an awful hack but it worked for me:

var f = path.resolve('someFile')
var now = Date.now() / 1000
var then = now - 10
fs.utimes(f, then, then, function (err) { if (err) throw err })

Update - This fix stopped working for me at some point, but Yassky’s solution further down the page works great.