bun-src/test/bundler/transpiler/react-compiler-fixtures/error.assign-global-in-jsx-children.expect.md

Input

function Component() {
  const foo = () => {
    someGlobal = true;
  };
  // Children are generally access/called during render, so
  // modifying a global in a children function is almost
  // certainly a mistake.
  return <Foo>{foo}</Foo>;
}

Error

Found 1 error:

Error: Cannot reassign variables declared outside of the component/hook

Variable `someGlobal` is declared outside of the component/hook. Reassigning this value during render is a form of side effect, which can cause unpredictable behavior depending on when the component happens to re-render. If this variable is used in rendering, use useState instead. Otherwise, consider updating it in an effect. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render).

error.assign-global-in-jsx-children.ts:3:4
  1 | function Component() {
  2 |   const foo = () => {
> 3 |     someGlobal = true;
    |     ^^^^^^^^^^ `someGlobal` cannot be reassigned
  4 |   };
  5 |   // Children are generally access/called during render, so
  6 |   // modifying a global in a children function is almost