next.js/test/integration/css-fixtures/custom-configuration/.postcssrc.json

{
  // Use comments to test JSON5 support
  "plugins": {
    // Test a non-standard feature that wouldn't be normally enabled
    "postcss-short-size": {
      // Add a prefix to test that configuration is passed
      "prefix": "xyz"
    },
    "postcss-trolling": false
  }
}