Support RegExp mountpoints

[phated]

This adds support for RegExp mountpoints. This can be used like:

process.pkg.mount(/(.+)\.gr$/, function (_match, group1) {
    return path.join(process.cwd(), group1 + '.gr.wasm');
});

This is useful for more complex patterns, like writing files matching the internal snapshot structure to the user's filesystem.

[robertsLando]

LGTM. cc @leerob @jesec @hipstersmoothie

[leerob]

Needs a test, but then good to go!

[phated]

I added a test, though I don't understand the directory naming so I named it with this PR number (test-1121-regexp-mountpoints).

This also helped me catch a case I overlooked in the readdirMountpoints function, so I hardened that too.

[phated]

Any idea why the pnpm stuff might be failing in CI?

[robertsLando]

@erossignon

[erossignon]

@erossignon

Any idea why the pnpm stuff might be failing in CI?

pnpm has recently been updated to version 6.0.0 , they seems to have droped support for nodejs <= 10.0

A easy fix would be to force a particular version of pnpm or to ignore the test when nodejs <=10 is detected.

[robertsLando]

I would skip tests for nodejs <= 10

[erossignon]

please merge #1122 first , this will fix the issue

[robertsLando]

@phated tests are failing here: https://github.com/vercel/pkg/pull/1121/checks?check_run_id=2285145037#step:8:25

[phated]

Sorry about that! I didn't take into account Windows path separators in my RegExp, but I simplified it and now the tests are passing.

[robertsLando]

Could this someway fix #1075 ?

[robertsLando]

LGTM

[jesec]

Could this someway fix #1075 ?

Very unlikely to be related.

By the way: Forgive me for being the “progress blocker” here. While those changes look good to me, IMO we should ship the new binaries before further feature changes.

[phated]

@leerob was there anything else you'd want me to do here?

[robertsLando]

@phated Wait for the 5.0.0 release then we can merge this :)

[erossignon]

I think this feature needs to be documented in the README.md.

[phated]

I think this feature needs to be documented in the README.md.

When I was digging into the project, mountpoints weren't documented at all. Has that changed?

[robertsLando]

@phated Could you add some docs about this feature please? I'm ok for this to land and I know there was no doc for this but I would like to make docs better

[erossignon]

requires added documentation in Readme.md

[jesec]

lg2m.

As for the documentation, currently there is no documentation for process.pkg.mount at all. I think the burden belongs to us maintainers instead of the author of the PR.

[robertsLando]

I think we can merge this so

[jesec]

@leerob Tests have been added by @phated . Can you re-review?

[erossignon]

@leerob let's go !

[phated]

Thanks all!