[Feature] keeping original whole or partial stats

[jskrzypek]

We have cordova hooks in our source folder (see the cordova hooks guide for more info: https://cordova.apache.org/docs/en/dev/guide/appdev/hooks/) that need to be copied into our destination folder and need to preserve the executable bit on their file mode (i.e. ls -l should print -rwxr-xr-x for these files).

Currently this doesn't happen, but it seems like it should be easy to do by passing a options object as a 3rd parameter to the to the fs.writeFileAsync() call in the writeFilePromises with the stat.mode from the fs.statAsync() call.

[jskrzypek]

I'm trying to implement this on my fork, but it doesn't seem to be working.

I'm happy to make the PR but I need a bit of guidance.

[kevlened]

The difficulty is in how we copy the files. By default, we add the files by adding them to compilation.assets and letting webpack take care of writing the files. The only time we write files with fs.writeFileAsync() is when a devServer is used (due to limitations of the server).

It's possible that this feature could piggyback on the additions needed for #15. That feature also requires fs.writeFileAsync for every file.