# `react-hooks-js/unsupported-syntax`

Validates against syntax that we do not plan to support in React Compiler

- **Category:** React Compiler
- **Severity:** error
- **Source:** eslint-plugin-react-hooks
- **Framework:** global
- **Enabled when:** eslint-plugin-react-hooks v6+ installed AND React Compiler detected in project
- **Documentation:** <https://react.dev/reference/eslint-plugin-react-hooks/lints/unsupported-syntax>

## Validation prompt

Use this to decide whether a fired diagnostic is real or a false positive.

Fires on syntax the Compiler permanently will not support — eval(...), with (...) {}, and the Function constructor — when used inside a component or hook. Both prevent any static analysis. False positive: the call sits in a non-component utility module the Compiler already skips (in that case the warning typically should not appear).

## Fix prompt

Use this once validation confirms the diagnostic is real.

Replace eval with bracket access (props[name] instead of eval('props.' + name)), JSON.parse for serialized data, or a dedicated expression parser like mathjs for arithmetic. Delete with statements and reference properties explicitly (Math.sin instead of with (Math) { sin(...) }). The legacy syntax has been discouraged for decades and modern equivalents exist for every use case. See https://react.dev/reference/eslint-plugin-react-hooks/lints/unsupported-syntax