cases / react-19-render

react-19-render

react-dom 18.2.0 → 19.0.0

React 19 removed the legacy ReactDOM.render entry point in favour of createRoot from react-dom/client.

npm fixture evals/fixtures/react-19-render

grep-baseline

2 right 2 wrong

<0.1s · $0.00

agent · deepseek-v4-flash-free

2 right 0 wrong

31.2s · $0.00

Release notes

The input. Checked in with the case so a scoring run measures the detector, not whether upstream's site is reachable.

React 19

Removed: `ReactDOM.render`

ReactDOM.render has been removed. Use createRoot from react-dom/client instead:

// Before
import ReactDOM from 'react-dom';
ReactDOM.render(<App />, container);

// After
import { createRoot } from 'react-dom/client';
createRoot(container).render(<App />);

Removed: `ReactDOM.hydrate`

ReactDOM.hydrate has been removed. Use hydrateRoot instead.

Removed: `unmountComponentAtNode`

Use root.unmount() instead.

What each detector said

One row per (file, symbol) site — the unit the scorer compares on. Ground truth comes from the case's hand-written labels.

4 sites · 2 where a detector is wrong only show mistakes

not broken src/components/Chart.jsx :render grep-baseline flagged agent · deepseek-v4-flash-free silent

A class component's own render() method. Survives React 19 untouched.
3 matched lines · reasoning
```
   3  // A class component's own render() method. Same identifier, unrelated to
   4  // ReactDOM.render, and completely unaffected by the React 19 removal.
   6  render() {
```
grep-baseline conf 0.50
'ReactDOM.render' is named in the release notes and appears in 8 place(s) in this repo. No check was made that these are real call sites.
not broken src/utils/template.js :render grep-baseline flagged agent · deepseek-v4-flash-free silent

A local string-templating helper. Unrelated to React.
2 matched lines · reasoning
```
   1  // A local helper that happens to be called render. Nothing to do with React.
   2  export function render(template, data) {
```
grep-baseline conf 0.50
'ReactDOM.render' is named in the release notes and appears in 8 place(s) in this repo. No check was made that these are real call sites.
breaks src/index.jsx :render grep-baseline flagged agent · deepseek-v4-flash-free flagged

Direct ReactDOM.render call.
1 matched line · reasoning
```
   6  ReactDOM.render(<App />, container);
```
grep-baseline conf 0.50
'ReactDOM.render' is named in the release notes and appears in 8 place(s) in this repo. No check was made that these are real call sites.
breaks src/legacy/mount.js :render grep-baseline flagged agent · deepseek-v4-flash-free flagged

Aliased import (`import RD from 'react-dom'`), so the dotted name never appears. Still a real call site.
2 matched lines · reasoning
```
   4  // Aliased import — the dotted name `ReactDOM.render` never appears here, but
   7  RD.render(LegacyWidget(props), el);
```
grep-baseline conf 0.50
'ReactDOM.render' is named in the release notes and appears in 8 place(s) in this repo. No check was made that these are real call sites.