Minify style attributes as well

src/minify/attr.rs

@@ -1,6 +1,11 @@
 use aho_corasick::{AhoCorasickBuilder, MatchKind};
 use lazy_static::lazy_static;
 
+#[cfg(feature = "js-esbuild")]
+use {
+    crate::minify::css::MINIFY_CSS_TRANSFORM_OPTIONS, crate::minify::esbuild::minify_using_esbuild,
+};
+
 use crate::gen::attrs::ATTRS;
 use crate::gen::codepoints::DIGIT;
 use crate::pattern::Replacer;
@@ -8,6 +13,7 @@ use crate::spec::entity::encode::encode_entities;
 use crate::spec::script::JAVASCRIPT_MIME_TYPES;
 use crate::spec::tag::ns::Namespace;
 use crate::whitespace::{collapse_whitespace, left_trim, right_trim};
+use crate::Cfg;
 
 fn build_double_quoted_replacer() -> Replacer {
     let mut patterns = Vec::<Vec<u8>>::new();
@@ -187,7 +193,13 @@ pub enum AttrMinified {
     Value(AttrMinifiedValue),
 }
 
-pub fn minify_attr(ns: Namespace, tag: &[u8], name: &[u8], mut value_raw: Vec<u8>) -> AttrMinified {
+pub fn minify_attr(
+    cfg: &Cfg,
+    ns: Namespace,
+    tag: &[u8],
+    name: &[u8],
+    mut value_raw: Vec<u8>,
+) -> AttrMinified {
     let attr_cfg = ATTRS.get(ns, tag, name);
 
     let should_collapse_and_trim = attr_cfg.filter(|attr| attr.collapse_and_trim).is_some();
@@ -203,6 +215,18 @@ pub fn minify_attr(ns: Namespace, tag: &[u8], name: &[u8], mut value_raw: Vec<u8
         collapse_whitespace(&mut value_raw);
     };
 
+    #[cfg(feature = "js-esbuild")]
+    if name == b"style" && cfg.minify_css {
+        let mut value_raw_min = Vec::new();
+        minify_using_esbuild(
+            &mut value_raw_min,
+            &value_raw,
+            &MINIFY_CSS_TRANSFORM_OPTIONS.clone(),
+            None,
+        );
+        value_raw = value_raw_min;
+    }
+
     if (value_raw.is_empty() && redundant_if_empty)
         || default_value.filter(|dv| dv == &value_raw).is_some()
         // TODO Cfg.

src/minify/css.rs

@@ -14,7 +14,7 @@ lazy_static! {
     static ref STYLE_END: AhoCorasick = AhoCorasickBuilder::new()
         .ascii_case_insensitive(true)
         .build(&["</style"]);
-    static ref TRANSFORM_OPTIONS: Arc<TransformOptions> = {
+    pub static ref MINIFY_CSS_TRANSFORM_OPTIONS: Arc<TransformOptions> = {
         let mut builder = TransformOptionsBuilder::new();
         builder.loader = Loader::CSS;
         builder.minify_identifiers = true;
@@ -34,6 +34,11 @@ pub fn minify_css(cfg: &Cfg, out: &mut Vec<u8>, code: &[u8]) {
     if !cfg.minify_css {
         out.extend_from_slice(&code);
     } else {
-        minify_using_esbuild(out, code, &TRANSFORM_OPTIONS.clone(), &STYLE_END);
+        minify_using_esbuild(
+            out,
+            code,
+            &MINIFY_CSS_TRANSFORM_OPTIONS.clone(),
+            Some(&STYLE_END),
+        );
     }
 }

src/minify/element.rs

@@ -46,7 +46,7 @@ pub fn minify_element(
         let mut attrs_sorted = attributes.into_iter().collect::<Vec<_>>();
         attrs_sorted.sort_unstable_by(|a, b| a.0.cmp(&b.0));
         for (name, value) in attrs_sorted {
-            let min = minify_attr(ns, tag_name, &name, value);
+            let min = minify_attr(cfg, ns, tag_name, &name, value);
             if let AttrMinified::Redundant = min {
                 continue;
             };

src/minify/esbuild.rs

@@ -3,38 +3,40 @@ use {aho_corasick::AhoCorasick, crossbeam::sync::WaitGroup, esbuild_rs::Transfor
 
 #[cfg(feature = "js-esbuild")]
 // TODO The use of WG is ugly and we don't want to be multi-threaded; wait for Rust port esbuild-transform-rs.
-// `tag_to_escape` must be case insensitive.
+// `tag_to_escape` must be case insensitive if provided.
 pub fn minify_using_esbuild(
     out: &mut Vec<u8>,
     code: &[u8],
     transform_options: &TransformOptions,
-    tag_to_escape: &'static AhoCorasick,
+    tag_to_escape: Option<&'static AhoCorasick>,
 ) {
     let wg = WaitGroup::new();
     unsafe {
         let wg = wg.clone();
         esbuild_rs::transform_direct_unmanaged(code, transform_options, move |result| {
-            // TODO (JS) Handle other forms:
-            // 1 < /script/.exec(a).length
-            // `  ${`  ${a</script/}  `}  `
-            // // </script>
-            // /* </script>
-            // Considerations:
-            // - Need to parse strings (e.g. "", '', ``) so syntax within strings aren't mistakenly interpreted as code.
-            // - Need to be able to parse regex literals to determine string delimiters aren't actually characters in the regex.
-            // - Determining whether a slash is division or regex requires a full-blown JS parser to handle all cases (this is a well-known JS parsing problem).
-            // - `/</script` or `/</ script` are not valid JS so don't need to be handled.
-            // TODO (CSS) Are there other places that can have unintentional closing tags?
-            tag_to_escape.replace_all_with_bytes(
-                result.code.as_str().trim().as_bytes(),
-                out,
-                |_, orig, dst| {
-                    dst.extend(b"<\\/");
-                    // Keep original case.
-                    dst.extend(&orig[2..]);
-                    true
-                },
-            );
+            let min_code = result.code.as_str().trim().as_bytes();
+            match tag_to_escape {
+                None => out.extend_from_slice(min_code),
+                // TODO (JS) Handle other forms:
+                // 1 < /script/.exec(a).length
+                // `  ${`  ${a</script/}  `}  `
+                // // </script>
+                // /* </script>
+                // Considerations:
+                // - Need to parse strings (e.g. "", '', ``) so syntax within strings aren't mistakenly interpreted as code.
+                // - Need to be able to parse regex literals to determine string delimiters aren't actually characters in the regex.
+                // - Determining whether a slash is division or regex requires a full-blown JS parser to handle all cases (this is a well-known JS parsing problem).
+                // - `/</script` or `/</ script` are not valid JS so don't need to be handled.
+                // TODO (CSS) Are there other places that can have unintentional closing tags?
+                Some(tag_to_escape) => {
+                    tag_to_escape.replace_all_with_bytes(min_code, out, |_, orig, dst| {
+                        dst.extend(b"<\\/");
+                        // Keep original case.
+                        dst.extend(&orig[2..]);
+                        true
+                    })
+                }
+            }
             drop(wg);
         });
     };

src/minify/js.rs

@@ -33,6 +33,6 @@ pub fn minify_js(cfg: &Cfg, out: &mut Vec<u8>, code: &[u8]) {
     if !cfg.minify_js {
         out.extend_from_slice(&code);
     } else {
-        minify_using_esbuild(out, code, &TRANSFORM_OPTIONS.clone(), &SCRIPT_END);
+        minify_using_esbuild(out, code, &TRANSFORM_OPTIONS.clone(), Some(&SCRIPT_END));
     }
 }

src/tests/mod.rs

@@ -596,8 +596,14 @@ fn test_js_minification_unintentional_closing_tag() {
 #[cfg(feature = "js-esbuild")]
 #[test]
 fn test_css_minification() {
+    // `<style>` contents.
     eval_with_css_min(
         b"<style>div { color: yellow }</style>",
         b"<style>div{color:#ff0}</style>",
     );
+    // `style` attributes.
+    eval_with_css_min(
+        br#"<div style="div { color: yellow }"></div>"#,
+        br#"<div style=div{color:#ff0}></div>"#,
+    );
 }