component tests fail after upgrading react native to 0.72.x

[siddarthkay]

Problem

After upgrading react-native,
make component-test fails with :

 SyntaxError: /Users/siddarthkumar/code/experiments/status-mobile/node_modules/@react-native/js-polyfills/error-guard.js: Missing semicolon. (14:4)

      12 | let _inGuard = 0;
      13 |
    > 14 | type ErrorHandler = (error: mixed, isFatal: boolean) => void;
         |     ^
      15 | type Fn<Args, Return> = (...Args) => Return;
      16 |
      17 | /**

Assumptions

• Caused due to upgrading versions of jest.
• This code is either not transformed properly so could be a change we need to make in babel config or jest config.
• Probably this file should have been ignored by jest and this looks like flow(react native uses flow for type checking) code so most likely a babel typescript plugin won't help.

Related links

• [Bug]: jest fails with @react-native/polyfills/error-guard.js jestjs/jest#12978 (This is the exact same error we have)
• https://jestjs.io/docs/configuration#transformignorepatterns-arraystring
• bug: @react-native/polyfills/error-guard.js not transpiled in distrobution facebook/react-native#33426 (same error in react-native repo)
• bug: Tests Fail Using Basic Configuration (React Native/TypeScript) swc-project/jest#85

Blocks #17241

[siddarthkay]

The issue was fixed by downgrading jest to 26.x
upgrading jest requires significant changes to our test suite and can be an independent task in itself
cc @J-Son89 @ilmotta

[ilmotta]

The issue was fixed by downgrading jest to 26.x upgrading jest requires significant changes to our test suite and can be an independent task in itself cc @J-Son89 @ilmotta

Thanks @siddarthkay. I forgot the number of times in my life I read the sentence "upgrading jest requires significant changes".