Vanilla React Native project doesn't work with @swc/jest based on usage instructions

[jzaefferer]

Describe the bug

When creating a vanilla React Native project, based on https://reactnative.dev/docs/environment-setup (run npx react-native@latest init AwesomeProjectSwc), then following the @swc/jest instructions for using swc with jest ( https://swc.rs/docs/usage/jest ), running yarn test will then fail with this unexpected error:

$ yarn test
yarn run v1.22.19
$ jest
 FAIL  __tests__/App.test.tsx
  ● Test suite failed to run


      × Expected ';', '}' or <eof>
        ╭─[~/AwesomeProjectSwc/node_modules/@react-native/js-polyfills/error-guard.js:11:1]
     11 │
     12 │ let _inGuard = 0;
     13 │
     14 │ type ErrorHandler = (error: mixed, isFatal: boolean) => void;
        · ──┬─ ────────────
        ·   ╰── This is the expression part of an expression statement
     15 │ type Fn<Args, Return> = (...Args) => Return;
     16 │
     17 │ /**
        ╰────


    Caused by:
        Syntax Error

      at Compiler.transformSync (node_modules/@swc/core/index.js:244:29)
      at transformSync (node_modules/@swc/core/index.js:351:21)
      at Object.process (node_modules/@swc/jest/index.js:73:45)
      at ScriptTransformer.transformSource (node_modules/@jest/transform/build/ScriptTransformer.js:545:31)
      at ScriptTransformer._transformAndBuildScript (node_modules/@jest/transform/build/ScriptTransformer.js:674:40)
      at ScriptTransformer.transform (node_modules/@jest/transform/build/ScriptTransformer.js:726:19)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        0.074 s
Ran all test suites.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Input code

No response

Config

No response

Playground link (or link to the minimal reproduction)

https://github.com/jzaefferer/swc-jest-react-native-repro

SWC Info output

$ npx -y swc-info@latest

Operating System:
    Platform: darwin
    Arch: arm64
    Machine Type: arm64
    Version: Darwin Kernel Version 22.5.0: Thu Jun  8 22:22:20 PDT 2023; root:xnu-8796.121.3~7/RELEASE_ARM64_T6000
    CPU: (10 cores)
        Models: Apple M1 Max

Binaries:
    Node: 16.19.1
    npm: 8.19.3
    Yarn: 1.22.19
    pnpm: 8.10.0

Relevant Packages:
    @swc/core: 1.3.95
    @swc/helpers: N/A
    @swc/types: 0.1.5
    typescript: 4.8.4

SWC Config:
    output: N/A
    .swcrc path: N/A

Next.js info:
    output: N/A

Expected behavior

Jest tests should run

Actual behavior

No response

Version

"@swc/core": "^1.3.95", "@swc/jest": "^0.2.29",

Additional context

swc-project/jest#40 (comment) looks somewhat related, but the suggested fix didn't work for me.

Looking for jest and this file name, which seems to be implemented in flow, I also found react-native-community/upgrade-support#152 - but adding the suggested transformIgnorePatterns didn't help either.

The repro repo uses the react-native Jest preset, which already includes transformIgnorePatterns: https://github.com/facebook/react-native/blob/0.72-stable/packages/react-native/jest-preset.js

https://github.com/swc-project/jest has more information than https://swc.rs/docs/usage/jest - might be worth linking to the GitHub readme. Though I didn't found a solution there either.

[kdy1]

swc-project/jest#85

It's not a bug of swc. Flow type should be stripped out before publishing a library.

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.