handle copying between identical files

[chinesedfan]

I hope this module can be as clever as cp. It should recognize copying between identical files and do nothing.

Now, v0.26.2, neither copy nor copySync can handle these cases correctly.

• If src and dst are the same file
  • It opens a read stream first, and then a write stream, which results in the file becomes empty.
• If src is symbolic link and points to dst
  • By default, option clobber is true, so that dst will be removed, which means the real file is removed. If clobber is false, the file becomes empty.
• If dst is symbolic link and points to src
  • Similar to the previous case, dst is removed and a new file is created, then the link is not existed any more. Or the file becomes empty.

I have added corresponding test cases in my branch.

[jprichardson]

Thanks for your interest. These are great suggestions. Would you be willing to look at the cp code and implement these changes? It would be of a huge help and really add a lot of value to the module. Even if we take one case at a time, that would be a wonderful addition.

Thank you!

[chinesedfan]

OK. I will try to find some time to implement this feature.

[jprichardson]

I think if you start with just one, that'd be a big win. You could pick the one that is the most important to you and we could start with that?

[RyanZim]

Fixed in 5.0.0 🎉