If 'format on save' is turned on, using formatter.ignore the Biome.js extension will format files that should be ignored.

// .vscode/settings.json
"settings": {
  "editor.formatOnSave": true
}

Using files.ignore the issue is fixed.

See biomejs/biome-vscode#189

// biome.json
{
  "files": {
    "ignore": ["node_modules", "no-format.js"]
  }
}

Using formatter.ignore the issue still persists.

// biome.json
{
  "formatter": {
    "ignore": ["node_modules", "no-format.js"]
  }
}

To reproduce:

git clone https://github.com/jrson83/biome-ignore-issue.git
cd biome-ignore-issue
pnpm install

Open packages/core/src/no-format.js and save the file. It should not format.