Use a better default browser list and fail gracefully when css parsing fails (#3509)

packages/cli-opt/src/css.rs

@@ -6,9 +6,9 @@ use grass::OutputStyle;
 use lightningcss::{
     printer::PrinterOptions,
     stylesheet::{MinifyOptions, ParserOptions, StyleSheet},
+    targets::{Browsers, Targets},
 };
 use manganis_core::CssAssetOptions;
-use tracing::{debug, warn};
 
 pub(crate) fn process_css(
     css_options: &CssAssetOptions,
@@ -18,7 +18,17 @@ pub(crate) fn process_css(
     let css = std::fs::read_to_string(source)?;
 
     let css = if css_options.minified() {
-        minify_css(&css)
+        // Try to minify the css. If we fail, log the error and use the unminified css
+        match minify_css(&css) {
+            Ok(minified) => minified,
+            Err(err) => {
+                tracing::error!(
+                    "Failed to minify css; Falling back to unminified css. Error: {}",
+                    err
+                );
+                css
+            }
+        }
     } else {
         css
     };
@@ -33,15 +43,39 @@ pub(crate) fn process_css(
     Ok(())
 }
 
-pub(crate) fn minify_css(css: &str) -> String {
-    let mut stylesheet = StyleSheet::parse(css, ParserOptions::default()).unwrap();
-    stylesheet.minify(MinifyOptions::default()).unwrap();
+pub(crate) fn minify_css(css: &str) -> anyhow::Result<String> {
+    let options = ParserOptions {
+        error_recovery: true,
+        ..Default::default()
+    };
+    let mut stylesheet = StyleSheet::parse(css, options).map_err(|err| err.into_owned())?;
+
+    // We load the browser list from the standard browser list file or use the browserslist default if we don't find any
+    // settings. Without the browser lists default, lightningcss will default to supporting only the newest versions of
+    // browsers.
+    let browsers_list = match Browsers::load_browserslist()? {
+        Some(browsers) => Some(browsers),
+        None => {
+            Browsers::from_browserslist(["defaults"]).expect("borwserslists should have defaults")
+        }
+    };
+
+    let targets = Targets {
+        browsers: browsers_list,
+        ..Default::default()
+    };
+
+    stylesheet.minify(MinifyOptions {
+        targets,
+        ..Default::default()
+    })?;
     let printer = PrinterOptions {
+        targets,
         minify: true,
         ..Default::default()
     };
-    let res = stylesheet.to_css(printer).unwrap();
-    res.code
+    let res = stylesheet.to_css(printer)?;
+    Ok(res.code)
 }
 
 /// Process an scss/sass file into css.
@@ -61,7 +95,7 @@ pub(crate) fn process_scss(
         .logger(&ScssLogger {});
 
     let css = grass::from_path(source, &options)?;
-    let minified = minify_css(&css);
+    let minified = minify_css(&css)?;
 
     std::fs::write(output_path, minified).with_context(|| {
         format!(
@@ -79,7 +113,7 @@ struct ScssLogger {}
 
 impl grass::Logger for ScssLogger {
     fn debug(&self, location: SpanLoc, message: &str) {
-        debug!(
+        tracing::debug!(
             "{}:{} DEBUG: {}",
             location.file.name(),
             location.begin.line + 1,
@@ -88,7 +122,7 @@ impl grass::Logger for ScssLogger {
     }
 
     fn warn(&self, location: SpanLoc, message: &str) {
-        warn!(
+        tracing::warn!(
             "Warning: {}\n    ./{}:{}:{}",
             message,
             location.file.name(),