fix(repack): support flow-parser in React Native 0.88

[whydidoo]

Summary

React Native 0.88 replaces the Hermes parser dependency in its Babel preset with flow-parser, which breaks Re.Pack's hard-coded parser lookup.

Resolve the parser and matching Babel syntax plugin from the application's React Native preset. Use the same resolution for the Babel loader, codegen, and Reanimated, while keeping support for older Hermes-based presets.

Fixes #1474.

Test plan

• Core and integration test suites, plus type checks.
• Parser regression tests for RN 0.87.0 and 0.88.0-rc.3 on Webpack and Rspack, covering JS, Flow, TypeScript, TSX, and codegen.
• Native Release builds on iOS Simulator and Android Emulator with Reanimated 4.7.1 and Worklets 0.13.0, using both babel-loader and babel-swc-loader. Verified UI-thread animation and completion callbacks.

RN 0.87 builds used a targeted ReactNativeFeatureFlags alias for an existing package exports issue, also reproduced with the old loader. RN 0.88 RC passed without it.

[changeset-bot]

🦋 Changeset detected

Latest commit: 546d223

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 6 packages

Name	Type
@callstack/repack	Patch
@callstack/repack-plugin-reanimated	Patch
@callstack/repack-plugin-expo-modules	Patch
@callstack/repack-plugin-nativewind	Patch
@callstack/repack-dev-server	Patch
@callstack/repack-init	Patch

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[CristiCeban]

Thanks for this! The parser change looks right to me. I checked the @react-native/babel-preset@0.88.0-rc.3 source: it uses require('flow-parser/babel-plugin') with parseLangTypes: 'flow' and reactRuntimeTarget: '19'. flow-parser@0.327.0 accepts the same parse() options Re.Pack already passes (babel, reactRuntimeTarget, sourceType), and it defaults to flow: 'detect' just like hermes-parser. So it's a drop-in swap.
What I verified:

• react-native-parser.test.ts passes locally (12 tests).
• I installed this branch into a fresh react-native@0.88.0-rc.3 app made with repack-init. The Cannot find module 'babel-plugin-syntax-hermes-parser' error is gone.
• With package exports enabled, iOS release, iOS dev and Android release all bundle. The iOS Release build runs on the simulator, and an MF2 host loading a remote over HTTP works, including a lazy chunk inside the remote and shared singletons.
  The issue command still fails after this PR. On a fresh repack-init project, the command from React Native 0.88.x support #1474 now fails with:

 Can't resolve 'react-native/react-private-interface'
 Can't resolve 'react-native/setup-env'
 Can't resolve '@react-native/asset-utils'

Which is separate one, it errors only when enablePackageExports: false. not related to this PR.
I've left a few smaller inline comments too.

[whydidoo]

Thanks for this! The parser change looks right to me. I checked the @react-native/babel-preset@0.88.0-rc.3 source: it uses require('flow-parser/babel-plugin') with parseLangTypes: 'flow' and reactRuntimeTarget: '19'. flow-parser@0.327.0 accepts the same parse() options Re.Pack already passes (babel, reactRuntimeTarget, sourceType), and it defaults to flow: 'detect' just like hermes-parser. So it's a drop-in swap. What I verified:

• react-native-parser.test.ts passes locally (12 tests).
• I installed this branch into a fresh react-native@0.88.0-rc.3 app made with repack-init. The Cannot find module 'babel-plugin-syntax-hermes-parser' error is gone.
• With package exports enabled, iOS release, iOS dev and Android release all bundle. The iOS Release build runs on the simulator, and an MF2 host loading a remote over HTTP works, including a lazy chunk inside the remote and shared singletons.
  The issue command still fails after this PR. On a fresh repack-init project, the command from React Native 0.88.x support #1474 now fails with:

 Can't resolve 'react-native/react-private-interface'
 Can't resolve 'react-native/setup-env'
 Can't resolve '@react-native/asset-utils'

Which is separate one, it errors only when enablePackageExports: false. not related to this PR. I've left a few smaller inline comments too.

Thanks for testing this! RN 0.88 exposes these entry points through package exports, so enablePackageExports: true is required in a standard Re.Pack setup. This is part of the RN 0.88 migration, and we should document that requirement alongside the parser fix.

[whydidoo]

@CristiCeban all were fixed

[dannyhw]

nice work, thanks @whydidoo 🙏