flush file system on copy

i have to ensure that the files copied using fse.copy() are actually written to the physical drive. i’m proposing a flag for it in the function’s options object.

this could be achieved by using fs.fsync() or possibly even by simply listening for the 'finish' event instead of the 'close' event.

second way sure is really easy to implement. however i’m unsure what “has been flushed to the underlying system” actually means.

if it flushes to windows’ write cache then it’s unsufficient.

[manidlou]

@Inve1951 thanks for your help here. We all appreciate your work. However, I am on the same page as @RyanZim. I am personally not inclined to add this feature. Primarily because I think it somehow breaks the overall consistency of fs-extra functions, as @RyanZim pointed out:

If we add this here, where else will we need to add it?

[RyanZim]

@jprichardson I’m not sure if this is within scope for fs-extra. If we add this here, where else will we need to add it? Personally, I think this warrants a separate module if we’re going to worry about this kind of low-level stuff.

CC: @manidlou