11ty-plugin-giallo/giallo-js/src/lib.rs

use giallo::{HighlightOptions, HtmlRenderer, Registry, RenderOptions, ThemeVariant};

mod bindings {
    //! Generated code derived from the `giallo-js.wit` definition.

    wit_bindgen::generate!({ path: "wit/giallo-js.wit" });

    use super::GialloJsComponent;
    export!(GialloJsComponent);
}

struct GialloJsComponent;

impl bindings::exports::brentsch::giallo_js::syntax_highlighter::Guest for GialloJsComponent {
    /// Rudimentary Wasm adapter around the basic
    /// [Giallo usage example](https://github.com/getzola/giallo/blob/a86755836dc4387056432f63f0b37b2c04b52711/examples/basic.rs).
    fn render_highlighted(
        code: String,
        language: String,
        theme_light: String,
        theme_dark: String,
    ) -> Result<String, String> {
        let mut registry = Registry::builtin().map_err(|err| err.to_string())?;
        registry.link_grammars();

        let options = HighlightOptions::new(
            language,
            ThemeVariant::Dual {
                light: &theme_light,
                dark: &theme_dark,
            },
        );
        let highlighted = registry
            .highlight(&code, &options)
            .map_err(|err| err.to_string())?;

        Ok(HtmlRenderer::default().render(&highlighted, &RenderOptions::default()))
    }
}