biomejs/biome · error

Expected root for comments with data

Error message

Expected root for comments with data

What it means

Error "Expected root for comments with data" thrown in biomejs/biome.

Source

Thrown at crates/biome_formatter/src/comments.rs:1017

    #[cfg(not(debug_assertions))]
    pub(crate) fn assert_formatted_all_comments(&self) {}

    #[cfg(debug_assertions)]
    pub(crate) fn assert_formatted_all_comments(&self) {
        let has_unformatted_comments = self
            .data
            .comments
            .all_parts()
            .any(|comment| !comment.formatted.get());

        if has_unformatted_comments {
            let mut unformatted_comments = Vec::new();

            for node in self
                .data
                .root
                .as_ref()
                .expect("Expected root for comments with data")
                .descendants()
            {
                unformatted_comments.extend(self.leading_comments(&node).iter().filter_map(
                    |comment| {
                        (!comment.formatted.get()).then_some(DebugComment::Leading {
                            node: node.clone(),
                            comment,
                        })
                    },
                ));
                unformatted_comments.extend(self.dangling_comments(&node).iter().filter_map(
                    |comment| {
                        (!comment.formatted.get()).then_some(DebugComment::Dangling {
                            node: node.clone(),
                            comment,
                        })
                    },
                ));

View on GitHub (pinned to 405dedb0ff)

Solutions

1. This is an internal formatter invariant violation; report it as a Biome bug with the source file that triggered it.
2. Ensure the comments iterator only runs on a fully parsed root node.

Example fix

// Report at https://github.com/biomejs/biome/issues with a minimal repro

When it happens

Trigger: Thrown at crates/biome_formatter/src/comments.rs:1017 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of biomejs/biome@405dedb0ff (2026-08-20). Data as JSON: /api/errors/c3f7ae9c856baa9b. Report an issue: GitHub.