On Windows, the following command works:

cp-cli README.md dist/my-lib/README.md

But the following commands don't work:

cp-cli README.md dist/my-lib/
cp-cli README.md dist/my-lib

According the docs the first one (with the slash) should work, but instead it gives the following error:

{ [Error: EPERM: operation not permitted, unlink 'C:\Projects\my-project\dist\my-lib']
  errno: -4048,
  code: 'EPERM',
  syscall: 'unlink',
  path:
   'C:\\Projects\\my-project\\dist\\my-lib' }

I solved this by adding the filename, but wanted to let you know. I don't know if this is also a problem on Unix systems.

Great work on this library by the way! cpx didn't want to copy a folder with assets and it hadn't been released for 3 years, so it's nice to see a fresh new copy library.

Looks like a nice, helpful little tool for compatibility. I can see it's a small wrapper and you're not going for anything complex.

One small feature I feel would be useful, though, is being able to specify a directory as the destination. In Linux-land, at least, doing this copies the source files, maintaining their names, into the destination directory. cp-cli currently just complains in that use case.

Since 9ef3453 the command cp-cli srcdir destdir is copying srcdir directory as a subdirectory of destdir. Before the change this would result in copying the content of srcdir inside destdir.

I think an additional check if source is a directory is required on line #24

The module has a build status badge on green deceiving the public about the reliability of the package.
The only existing test :

describe('cp-cli', () => {
  it('should do anything', () => {
    expect(true).to.be.true();
  });