[Bug]: rspack serve fails with InvalidArg if Rule.options has function in it

[skoch13]

System Info

System:
OS: macOS 15.0.1
CPU: (10) arm64 Apple M1 Max
Memory: 1.92 GB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Node: 20.16.0 - ~/.local/state/fnm_multishells/79899_1729519945071/bin/node
npm: 10.8.1 - ~/.local/state/fnm_multishells/79899_1729519945071/bin/npm
pnpm: 9.12.2 - ~/.local/state/fnm_multishells/79899_1729519945071/bin/pnpm
Browsers:
Chrome: 130.0.6723.59
Safari: 18.0.1
npmPackages:
@rspack/cli: 1.0.13 => 1.0.13
@rspack/core: 1.0.13 => 1.0.13
@rspack/plugin-react-refresh: 1.0.0 => 1.0.0

Details

In attempt to migrate from webpack I stumbled upon the following error that is a little bit hard to trace, but the root cause is the following:

ts-loader allows to provide options.getCustomTransformers as function.

  {
    test: /\.tsx?$/,
    loader: 'builtin:swc-loader',
    type: 'javascript/auto',
    options: {
      getCustomTransformers: () => {}
...
...

Starting the web server results in the following error:

/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:17883
    this.#instance = new instanceBinding.Rspack(
                     ^
Error: JS functions cannot be represented as a serde_json::Value
    at _Compiler.#getInstance (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:17883:22)
    at _Compiler.#build (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:17330:22)
    at /Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:17302:18
    at done (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/lite-tapable/dist/index.js:473:13)
    at AsyncSeriesHook.callAsyncStageRange (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/lite-tapable/dist/index.js:480:20)
    at AsyncSeriesHook.callAsync (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/lite-tapable/dist/index.js:82:21)
    at _Compiler.compile (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:17296:30)
    at /Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/core/dist/index.js:16733:21
    at done (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/lite-tapable/dist/index.js:473:13)
    at next (/Users/user/PATH/node_modules/.pnpm/@[email protected]/node_modules/@rspack/lite-tapable/dist/index.js:533:25) {
  code: 'InvalidArg'
}

Is it possible to improve error message here?

Reproduce link

https://github.com/skoch13/rspack-repro

Reproduce Steps

1. add function inside of Rule.options
2. execute rspack serve

or check repro at https://github.com/skoch13/rspack-repro

[inottn]

The builtin:swc-loader does not support the getCustomTransformers option. See https://rspack.dev/guide/features/builtin-swc-loader for more details.

[skoch13]

@inottn thank you for your reply. I did understand that eventually, but my question was, is it possible to improve error messaging here?