Replace acorn with Oxc

[TheAlexLichter]

Describe the feature

Using oxc-parser (or oxc-walker) in unctx could improve speed of the library.

This wouldn't be the first case where acorn is replace, see e.g. nuxt/nuxt#30066

Additional information

• Would you be willing to help implement this feature?

[pi0]

This is a little tricky, as adding native dependencies adds ~3.8MB of native deps.

Can you help adding an experimental transform-oxc.ts file with optional deps as first step?

[pi0]

(for additional context, i was waiting for OXC parsers to be fully acorn compliant so we could have reusable transform logic with changable parser. not sure how is the latest status of that)

[TheAlexLichter]

Sure, happy to give it a try 👍🏻

I think the main thing that is blocking 1:1 migration is the missing loc field (oxc-project/oxc#10307) - range exists though. More info on alignment oxc-project/oxc#10307 (comment)

[overlookmotel]

Just FYI: range field is fully implemented (oxc-parser has an option to enable it). loc is not.

range and loc aside, the AST produced by oxc-parser is 100% compatible with Acorn. We have conformance testing which compares the AST produced by Oxc and by Acorn for all Test262's 48,000 test cases. 100% pass.

In addition, Oxc's AST for TS files is identical to those produced by TS-ESLint (again, with a large conformance test suite to make sure).

So, basically, if you don't need loc, oxc-parser is a drop-in replacement for Acorn.

[TheAlexLichter]

With that and #113, lmk if you have you have other concerns @pi0

(We can move to a loc based approach as soon as loc is actually implemented but the current code works without it 👏🏻)