Merge pull request #8211 from meeseeksmachine/auto-backport-of-pr-821…

…0-on-1.2.x

Backport PR #8210 on branch 1.2.x (Clean up file watching)

dev_mode/webpack.config.js

@@ -60,30 +60,6 @@ Object.keys(jlab.linkedPackages).forEach(function(name) {
   watched[name] = plib.dirname(localPkgPath);
 });
 
-/**
- * Sync a local path to a linked package path if they are files and differ.
- */
-function maybeSync(localPath, name, rest) {
-  const stats = fs.statSync(localPath);
-  if (!stats.isFile(localPath)) {
-    return;
-  }
-  const source = fs.realpathSync(plib.join(jlab.linkedPackages[name], rest));
-  if (source === fs.realpathSync(localPath)) {
-    return;
-  }
-  fs.watchFile(source, { interval: 500 }, function(curr) {
-    if (!curr || curr.nlink === 0) {
-      return;
-    }
-    try {
-      fs.copySync(source, localPath);
-    } catch (err) {
-      console.error(err);
-    }
-  });
-}
-
 /**
  * A filter function set up to exclude all files that are not
  * in a package contained by the Jupyterlab repo. Used to ignore
@@ -107,7 +83,6 @@ function ignored(path) {
     const rest = path.slice(rootPath.length);
     if (rest.indexOf('node_modules') === -1) {
       ignore = false;
-      maybeSync(path, name, rest);
     }
     return true;
   });
@@ -210,7 +185,8 @@ module.exports = [
       ]
     },
     watchOptions: {
-      poll: 333
+      poll: 500,
+      aggregateTimeout: 1000
     },
     node: {
       fs: 'empty'