Feat: Manganis SCSS Support (#3294)

* feat: scss manganis support

* revision: make ScssLogger private

packages/cli-opt/src/css.rs

@@ -1,11 +1,14 @@
 use std::path::Path;
 
 use anyhow::Context;
+use codemap::SpanLoc;
+use grass::OutputStyle;
 use lightningcss::{
     printer::PrinterOptions,
     stylesheet::{MinifyOptions, ParserOptions, StyleSheet},
 };
 use manganis_core::CssAssetOptions;
+use tracing::{debug, warn};
 
 pub(crate) fn process_css(
     css_options: &CssAssetOptions,
@@ -40,3 +43,57 @@ pub(crate) fn minify_css(css: &str) -> String {
     let res = stylesheet.to_css(printer).unwrap();
     res.code
 }
+
+/// Process an scss/sass file into css.
+pub(crate) fn process_scss(
+    scss_options: &CssAssetOptions,
+    source: &Path,
+    output_path: &Path,
+) -> anyhow::Result<()> {
+    let style = match scss_options.minified() {
+        true => OutputStyle::Compressed,
+        false => OutputStyle::Expanded,
+    };
+
+    let options = grass::Options::default()
+        .style(style)
+        .quiet(false)
+        .logger(&ScssLogger {});
+
+    let css = grass::from_path(source, &options)?;
+    let minified = minify_css(&css);
+
+    std::fs::write(output_path, minified).with_context(|| {
+        format!(
+            "Failed to write css to output location: {}",
+            output_path.display()
+        )
+    })?;
+
+    Ok(())
+}
+
+/// Logger for Grass that re-uses their StdLogger formatting but with tracing.
+#[derive(Debug)]
+struct ScssLogger {}
+
+impl grass::Logger for ScssLogger {
+    fn debug(&self, location: SpanLoc, message: &str) {
+        debug!(
+            "{}:{} DEBUG: {}",
+            location.file.name(),
+            location.begin.line + 1,
+            message
+        );
+    }
+
+    fn warn(&self, location: SpanLoc, message: &str) {
+        warn!(
+            "Warning: {}\n    ./{}:{}:{}",
+            message,
+            location.file.name(),
+            location.begin.line + 1,
+            location.begin.column + 1
+        );
+    }
+}