polyfill node's fs.cp.

[everett1992]

I need recursive copy to implement npm/cli#4082. I can probably use mkdir --recursive and paclist to copy module's files but I'll need cp recursive to copy modules in node_modules.

Like lib/rm/polyfill.js this is a copy/modification of code in nodejs, which is in turn lifted from a popular npm package (fs-extra in this case).

• I may have gone overboard supporting various error classes.
• I did not implement node's argument validation. I only enforce that opts is an object and set defaults.
• I only copied the promise interface, not sync or callback.

[nlf]

i just landed #7 which reduces the CI test matrix a bit and makes that a little less scary (currently a lot of the failures in CI are due to testing on node versions that npm doesn't officially support)

can you rebase this on the latest main?

additionally, we'll need you to put the license for cp in a separate file at lib/cp/LICENSE.md

after those two changes we'll have a more clear picture of what still may need fixing, but judging by what i'm seeing we have at least one test that has failing assertions, and we're missing a line of coverage, both in Windows. i'm happy to help you track down how to fix those after a rebase!

[nlf]

awesome! one last thing, can you add a note to the README about this module providing an fs.cp polyfill? once that's in place i think we're good to land this. thank you!

[nlf]

beautiful! thank you!

[nlf]

just published this as @npmcli/[email protected]

thank you again, this is great!