Improve closing tag escaping

src/proc/mod.rs

@@ -8,7 +8,6 @@ use memchr::memchr;
 #[cfg(feature = "js-esbuild")]
 use {
     crossbeam::sync::WaitGroup,
-    esbuild_rs::TransformResult,
     std::sync::{Arc, Mutex},
 };
 
@@ -54,7 +53,7 @@ pub enum MatchAction {
 #[cfg(feature = "js-esbuild")]
 pub struct EsbuildSection {
     pub src: ProcessorRange,
-    pub result: TransformResult,
+    pub escaped: Vec<u8>,
 }
 
 // Processing state of a file. Single use only; create one per processing.
@@ -381,21 +380,10 @@ impl<'d> Processor<'d> {
         // the write pointer after previous compaction.
         // If there are no script sections, then we get self.write_next which will be returned.
         let mut write_next = results.get(0).map_or(self.write_next, |r| r.src.start);
-        for (i, EsbuildSection { result, src }) in results.iter().enumerate() {
+        for (i, EsbuildSection { escaped: min_code, src }) in results.iter().enumerate() {
             // Resulting minified JS/CSS to write.
-            // TODO 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.
-            let min_code = result.code.as_str().trim().replace("</script", "<\\/script");
             let min_len = if min_code.len() < src.len() {
-                self.code[write_next..write_next + min_code.len()].copy_from_slice(min_code.as_bytes());
+                self.code[write_next..write_next + min_code.len()].copy_from_slice(min_code);
                 min_code.len()
             } else {
                 // If minified result is actually longer than source, then write source instead.

src/tests/mod.rs

@@ -454,7 +454,9 @@ fn test_js_minification() {
 #[test]
 fn test_js_minification_unintentional_closing_tag() {
     eval_with_js_min(br#"<script>let a = "</" + "script>";</script>"#, br#"<script>let a="<\/script>";</script>"#);
+    eval_with_js_min(br#"<script>let a = "</S" + "cRiPT>";</script>"#, br#"<script>let a="<\/ScRiPT>";</script>"#);
     eval_with_js_min(br#"<script>let a = "\u003c/script>";</script>"#, br#"<script>let a="<\/script>";</script>"#);
+    eval_with_js_min(br#"<script>let a = "\u003c/scrIPt>";</script>"#, br#"<script>let a="<\/scrIPt>";</script>"#);
 }
 
 #[cfg(feature = "js-esbuild")]

src/unit/script.rs

@@ -46,9 +46,31 @@ pub fn process_script(proc: &mut Processor, cfg: &Cfg, js: bool) -> ProcessingRe
         unsafe {
             esbuild_rs::transform_direct_unmanaged(&proc[src], &TRANSFORM_OPTIONS.clone(), move |result| {
                 let mut guard = results.lock().unwrap();
+                // TODO 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.
+                let mut escaped = Vec::<u8>::new();
+                // SCRIPT_END must be case insensitive.
+                SCRIPT_END.replace_all_with_bytes(
+                    result.code.as_str().trim().as_bytes(),
+                    &mut escaped,
+                    |_, orig, dst| {
+                        dst.extend(b"<\\/");
+                        // Keep original case.
+                        dst.extend(&orig[2..]);
+                        true
+                    },
+                );
                 guard.push(EsbuildSection {
                     src,
-                    result,
+                    escaped,
                 });
                 // Drop Arc reference and Mutex guard before marking task as complete as it's possible proc::finish
                 // waiting on WaitGroup will resume before Arc/Mutex is dropped after exiting this function.

src/unit/style.rs

@@ -1,17 +1,19 @@
 use aho_corasick::{AhoCorasick, AhoCorasickBuilder};
 use lazy_static::lazy_static;
+
+#[cfg(feature = "js-esbuild")]
+use {
+    crate::proc::checkpoint::WriteCheckpoint,
+    crate::proc::EsbuildSection,
+    esbuild_rs::{Loader, TransformOptions, TransformOptionsBuilder},
+    std::sync::Arc,
+};
+
+use crate::Cfg;
 use crate::err::ProcessingResult;
 use crate::proc::MatchAction::*;
 use crate::proc::MatchMode::*;
 use crate::proc::Processor;
-#[cfg(feature = "js-esbuild")]
-use {
-    std::sync::Arc,
-    esbuild_rs::{Loader, TransformOptionsBuilder, TransformOptions},
-    crate::proc::EsbuildSection,
-    crate::proc::checkpoint::WriteCheckpoint,
-};
-use crate::Cfg;
 
 #[cfg(feature = "js-esbuild")]
 lazy_static! {
@@ -32,7 +34,7 @@ lazy_static! {
 #[inline(always)]
 pub fn process_style(proc: &mut Processor, cfg: &Cfg) -> ProcessingResult<()> {
     #[cfg(feature = "js-esbuild")]
-    let start = WriteCheckpoint::new(proc);
+        let start = WriteCheckpoint::new(proc);
     proc.require_not_at_end()?;
     proc.m(WhileNotSeq(&STYLE_END), Keep);
     // `process_tag` will require closing tag.
@@ -45,9 +47,22 @@ pub fn process_style(proc: &mut Processor, cfg: &Cfg) -> ProcessingResult<()> {
         unsafe {
             esbuild_rs::transform_direct_unmanaged(&proc[src], &TRANSFORM_OPTIONS.clone(), move |result| {
                 let mut guard = results.lock().unwrap();
+                // TODO Are there other places that can have unintentional closing tags?
+                let mut escaped = Vec::<u8>::new();
+                // STYLE_END must be case insensitive.
+                STYLE_END.replace_all_with_bytes(
+                    result.code.as_str().trim().as_bytes(),
+                    &mut escaped,
+                    |_, orig, dst| {
+                        dst.extend(b"<\\/");
+                        // Keep original case.
+                        dst.extend(&orig[2..]);
+                        true
+                    },
+                );
                 guard.push(EsbuildSection {
                     src,
-                    result,
+                    escaped,
                 });
                 // Drop Arc reference and Mutex guard before marking task as complete as it's possible proc::finish
                 // waiting on WaitGroup will resume before Arc/Mutex is dropped after exiting this function.