refactor: switch css minification to lighteningcss

lighteningcss already got pulled in through a minify-html upgrade. So
we now to have use that pinned version anyway, and we can go ahead,
dropping css-minify.

Cargo.toml

@@ -31,7 +31,6 @@ cargo-lock = "9"
 cargo_metadata = "0.18.1"
 clap = { version = "4", features = ["derive", "env"] }
 console = "0.15"
-css-minify = "0.3"
 directories = "5"
 dunce = "1"
 envy = "0.4"
@@ -76,7 +75,7 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 which = "5"
 zip = "0.6"
 
-# pin lightningcss, pulled in by minify-html
+# pin lightningcss, used by trunk, also pulled in by minify-html
 lightningcss = "=1.0.0-alpha.51"
 
 [dev-dependencies]

src/processing/minify.rs

@@ -16,18 +16,35 @@ pub fn minify_js(bytes: Vec<u8>, mode: TopLevelMode) -> Vec<u8> {
 
 /// perform CSS minification
 pub fn minify_css(bytes: Vec<u8>) -> Vec<u8> {
-    use css_minify::optimizations::*;
-
-    if let Ok(css) = std::str::from_utf8(&bytes) {
-        match Minifier::default().minify(css, Level::One) {
-            Ok(result) => return result.into_bytes(),
-            Err(err) => {
-                tracing::warn!("Failed to minify CSS: {err}");
-            }
-        }
+    use lightningcss::stylesheet::*;
+
+    /// wrap CSS minification to isolate borrowing the original content
+    fn minify(css: &str) -> Result<String, ()> {
+        // parse CSS
+
+        let mut css = StyleSheet::parse(css, ParserOptions::default()).map_err(|err| {
+            tracing::warn!("CSS parsing failed, skipping: {err}");
+        })?;
+
+        css.minify(MinifyOptions::default()).map_err(|err| {
+            tracing::warn!("CSS minification failed, skipping: {err}");
+        })?;
+
+        Ok(css
+            .to_css(PrinterOptions {
+                minify: true,
+                ..Default::default()
+            })
+            .map_err(|err| {
+                tracing::warn!("CSS generation failed, skipping: {err}");
+            })?
+            .code)
     }
 
-    bytes
+    match std::str::from_utf8(&bytes) {
+        Ok(css) => minify(css).map(String::into_bytes).unwrap_or(bytes),
+        Err(_) => bytes,
+    }
 }
 
 /// perform HTML minification