[Bug] SWC panic crash with React Native 0.84.0-rc.0: "Object rest pattern should be removed by es2018::object_rest_spread pass"

[nthtrung09it]

Description

When using Re.Pack 5.2.3 with React Native 0.84.0-rc.0, the bundler crashes immediately with a Rust panic in SWC during the ES2015 destructuring transform.

Environment

• Re.Pack version: 5.2.3
• @rspack/core version: 1.5.8
• @swc/core version: 1.13.5
• React Native version: 0.84.0-rc.0
• Node.js version: v22.21.1
• pnpm version: 10.27.0
• OS: macOS (Darwin 24.6.0, arm64)

Error Message

▄▀▀▀ ▀▀▀▀   █▀▀█ █▀▀█ ▄▀▀▀ █  █
█    ▀▀▀▀   █▀▀▀ █▀▀█ █    █▀▀▄
▀    ▀▀▀▀ ▀ ▀    ▀  ▀  ▀▀▀ ▀  ▀
5.2.3, powered by Rspack

ℹ [DevServer] Server listening at http://127.0.0.1:8081 
⠴ [DevServer] [===-------------] 16% ios 
Panic occurred at runtime. Please file an issue on GitHub with the backtrace below: https://github.com/web-infra-dev/rspack/issues: panicked at index.crates.io-1949cf8c6b5b557f/swc_ecma_compat_es2015-28.0.0/src/destructuring.rs:419:52:
internal error: entered unreachable code: Object rest pattern should be removed by es2018::object_rest_spread pass

Steps to Reproduce

1. Create a React Native 0.84.0-rc.0 project with Re.Pack 5.2.3
2. Run react-native webpack-start --config rspack.config.mts --port 8081 --platform ios
3. The bundler crashes at ~16-30% progress with the panic above

Configuration

Using @callstack/repack/babel-swc-loader as recommended:

{
  test: /\.[cm]?[jt]sx?$/,
  use: {
    loader: '@callstack/repack/babel-swc-loader',
    parallel: true,
    options: {},
  },
  type: 'javascript/auto',
}

Analysis

The panic occurs in swc_ecma_compat_es2015/src/destructuring.rs:419:52, indicating that the ES2018 object_rest_spread pass didn't run before the ES2015 destructuring pass, causing an unexpected object rest pattern ({...rest}) to reach the destructuring handler.

This appears to be related to:

• swc-project/swc#2531
• swc-project/swc#3523

Expected Behavior

The bundler should successfully compile React Native 0.84.0-rc.0 code without panicking.

Additional Context

• The crash happens very early in bundling (~16%), suggesting it's hitting core RN code or a common dependency
• No verbose output shows which file triggers the crash
• This worked on React Native 0.83.1

Workaround Attempts

• Updated to @callstack/repack 5.2.3 - still crashes
• Tried running with --verbose - panic occurs before file info is logged

[jbroma]

Hi, try bumping the @rspack/core version, it will ship with newer versions of swc so the issue might resolve itself

[nthtrung09it]

Thanks for the suggestion! I updated the dependencies:

Updated versions:

• @rspack/core: 1.5.8 → 1.7.1
• @swc/core: 1.13.5 → 1.15.8

Unfortunately, the panic still occurs. The error message now shows a newer swc version but the same bug:

Panic occurred at runtime: panicked at index.crates.io-1949cf8c6b5b557f/swc_ecma_compat_es2015-39.0.0/src/destructuring.rs:422:52:
internal error: entered unreachable code: Object rest pattern should be removed by es2018::object_rest_spread pass

Note the swc version changed from swc_ecma_compat_es2015-28.0.0 to swc_ecma_compat_es2015-39.0.0, so the update did take effect, but the bug persists in the newer version as well.

The crash now happens at ~31% instead of ~16%, so it might be hitting a different file, but the underlying issue remains.

[nthtrung09it]

Opus 4.5 is too strong, haha ^^