process: add process.features.typescript

[RedYetiDev]

Fixes #54294

[nodejs-github-bot]

Review requested:

• @nodejs/startup

[RedYetiDev]

Drafting, as there may be a way to get the arg in CPP

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.40%. Comparing base (d24c731) to head (74a8769).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #54295   +/-   ##
=======================================
  Coverage   88.39%   88.40%           
=======================================
  Files         652      652           
  Lines      186568   186591   +23     
  Branches    36047    36050    +3     
=======================================
+ Hits       164924   164952   +28     
+ Misses      14915    14912    -3     
+ Partials     6729     6727    -2     

Files with missing lines	Coverage Δ
lib/internal/bootstrap/node.js	99.78% <100.00%> (+0.01%)	⬆️

... and 25 files with indirect coverage changes

[H4ad]

Maybe process.features.stripTypes is not better?

Also, there's no other way to check if any flag is enabled? I know there is inside the codebase but I don't remember to see it exposed

[RedYetiDev]

Also, there's no other way to check if any flag is enabled? I know there is inside the codebase but I don't remember to see it exposed

It's pretty late where I am, but I'm going to investigate alternative approaches tomorrow

[RedYetiDev]

Maybe process.features.stripTypes is not better?

I feel like if more typescript support is added, E.G. #54283, it does more than just strip types.

[marco-ippolito]

since we have 2 levels of typescript support, instead of boolean it would be better to return { mode: "transform" // or strip-only }

[silverwind]

since we have 2 levels of typescript support, instead of boolean it would be better to return { mode: "transform" // or strip-only }

Hmm, not sure that would fit in process.features. In my case, I'm primarly after knowing whether the current process can load typescript, I wouldn't care about those modes as long as they both give typescript loading support.

[legendecas]

/cc @nodejs/typescript

[anonrig]

I don't think we should add this. This feature can easily be added as a userland module. I don't think we should add more attributes to global variables unless we have a compelling reason.

[silverwind]

I don't think we should add this. This feature can easily be added as a userland module. I don't think we should add more attributes to global variables unless we have a compelling reason.

Please demonstrate how one can do this in a future-proof way that continues to work once the flag is made the default. I see none.

[marco-ippolito]

I'm ok with this feature since otherwise user need to check process.argv or process.execArgv or NODE_OPTIONS.
We already have it for some other features so why not.

marcoippolito@marcos-MacBook-Pro amaro % node -p "process.features"
{
  inspector: true,
  debug: false,
  uv: true,
  ipv6: true,
  tls_alpn: true,
  tls_sni: true,
  tls_ocsp: true,
  tls: true,
  cached_builtins: [Getter]
}

But it needs to be a getter like cached_builtins and return an object

[RedYetiDev]

But it needs to be a getter like cached_builtins and return an object

I can update it to be a getter and return an object

[RedYetiDev]

Right now I have it like @legendecas suggested, that is, strip when --experimental-strip-types and transform when --experimental-transform-types, would you prefer your suggestion:

{ mode: "transform" // or strip-only }

[marco-ippolito]

@anonrig can you check if your concerns have been resolved?

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/62813/

[jasnell]

CI is good but unfortunately this needs a rebase and yet another CI run.

[anonrig]

I left a comment to one of my comments, that has been "resolved" but it isn't.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/62867/

[RedYetiDev]

Do I need to rebase to resolve the github CI failures, or can this land without them?

[richardlau]

Do I need to rebase to resolve the github CI failures, or can this land without them?

Unfortunately, yes, you will need to rebase.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/62887/

[RedYetiDev]

This needs yet another rebase 😭

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/62897/