💅 Biome is adding a comma in the last line inside ReactDOM.createRoot.render method in main.tsx file when executing npx biome check --apply ./src

[CarmeloRicarte]

Environment information

CLI:
  Version:                      1.7.1
  Color support:                true

Platform:
  CPU Architecture:             aarch64
  OS:                           macos

Environment:
  BIOME_LOG_DIR:                unset
  NO_COLOR:                     unset
  TERM:                         "xterm-256color"
  JS_RUNTIME_VERSION:           "v18.15.0"
  JS_RUNTIME_NAME:              "node"
  NODE_PACKAGE_MANAGER:         "npm/9.5.0"

Biome Configuration:
  Status:                       Loaded successfully
  Formatter disabled:           false
  Linter disabled:              false
  Organize imports disabled:    false
  VCS disabled:                 true

Linter:
  Recommended:                  true
  All:                          false
  Rules:
Workspace:
  Open Documents:               0

Rule name

no specific rule added

Playground link

https://codesandbox.io/p/devbox/biomejs-bug-react-render-xtw6n7

Expected result

It should not add this comma after </React.StrictMode> like in this example:

import React from "react";
import ReactDOM from "react-dom/client";
import App from "./App.tsx";
import "./index.css";

ReactDOM.createRoot(document.getElementById("root")!).render(
  <React.StrictMode>
    <App />
  </React.StrictMode>
);

Code of Conduct

• I agree to follow Biome's Code of Conduct

[ematipico]

Interestingly, Prettier has the same issue.

[ah-yu]

It seems they behave differently when setting trailing_comma to es5. playground

[ematipico]

I believe this is expected and it's not a bug.

When the list of parameters breaks on multiple lines, the formatter always adds a leading comma for the last parameter. In this case, the last is also the first.

However, the es5 trialing comma is definitely buggy, and we should fix it (with low priority I suppose)