formatter-development

Building a Biome formatter involves generating boilerplate for the target language to produce FormatNodeRule implementations, then defining node-specific formatting logic using IR primitives like space, line breaks, groups, and indentation.

IR generation in Biome code formatting creates intermediate representation primitives like groups, line breaks, and indentation blocks. These primitives enable you to craft robust, maintainable formatting logic that handles tokens and comments.

Yes, you can compare Biome formatted output against Prettier to validate consistency. This workflow ensures your custom formatter achieves cross-language consistency for JavaScript, CSS, JSON, and HTML.

To test Biome formatter behavior, you extend test suites by adding test specifications in the tests/specs directory and running cargo test. This workflow verifies that your node-specific formatting rules behave as expected.

Yes, Biome formatter development supports HTML and CSS. You can apply the trait-based formatting workflow to implement syntax support across multiple languages, including HTML, JavaScript, CSS, and JSON.

The best way to handle comments in a Biome formatter is to implement specific comment handling logic within your FormatNodeRule. This ensures comments integrate cleanly with IR-generated line breaks and indentation groups.