feat(es/parser): Support stripping flow with ES parser

[kdy1]

Description:

This PR adds support for flow syntax without a feature to construct AST. The parser strips out extra syntax, and the returned AST is identical to ECMAScript AST.

[rtrembecky]

hello, last week I found out I can't switch to @swc/jest for a React Native project, where react-native and expo dependencies need to be transformed, because they include the Flow types. do you think this will be merged in the foreseeable future? thanks.

[rtrembecky]

BTW I found https://github.com/changwoolab/flow-aware-swc-jest and tried it but also got some error. just sharing for visibility/reference

[rtrembecky]

@kdy1 hi, any update on this effort?

[kdy1]

@rtrembecky Is there any concrete use plan?

[kdy1]

Ah you want to use swc/jest for a RN project

[rtrembecky]

well it's simple, our RN tests take too long to spin and one of the issues I identified is babel transpilation of RN modules, which are being shipped with Flow. I'd like to switch to a faster engine (SWC) but still support Flow-stripping.

[jbroma]

In Re.Pack 5 we're using swc through Rspack and right now we're stripping flow types with flow-remove-types utility.

It would be amazing to have a builtin support for doing this with swc 🙌

[changeset-bot]

⚠️ No Changeset found

Latest commit: 61ff623

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[codspeed-hq]

CodSpeed Performance Report

Merging #9114 will improve performances by 3.43%

_{Comparing kdy1:flow-parser (61ff623) with main (c135f71)}

Summary

⚡ 1 improvements
✅ 193 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	kdy1:flow-parser	Change
⚡	es/visitor/base-perf/boxing_unboxed_clone	2.6 µs	2.6 µs	+3.43%