[Compiler Bug]: Compiler-generated _c reference breaks inline JSX components in jest.mock() factories

What kind of issue is this?

• React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
• babel-plugin-react-compiler (build issue installing or using the Babel plugin)
• eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
• react-compiler-healthcheck (build issue installing or using the healthcheck script)

Link to repro

https://github.com/Aryan4123/react-compiler-jest-mock-repro/pull/1

Repro steps

1. Check out PR: https://github.com/Aryan4123/react-compiler-jest-mock-repro/pull/1

2. Run npm install.

3. Run npm test.

4. Jest fails during Babel transformation with:

   The module factory of jest.mock() is not allowed to reference any out-of-scope variables.
Invalid variable access: _c

The mock factory declares an inline JSX component. React Compiler transforms that component and references its generated module cache helper _c from inside the factory. Jest's hoist transform rejects _c as an out-of-scope variable before the test executes.

Expected: the test should transform and execute successfully.

Controls:

• npm run test:no-compiler passes with the same test and React Compiler disabled.
• npm run test:workaround passes with React Compiler enabled and a file-level 'use no memo' directive.

How often does this bug happen?

Every time

What version of React are you using?

19.2.4

What version of React Compiler are you using?

1.0.0