feat(ecma/parser): add the allow_return_outside_function option

crates/swc_ecma_parser/src/lib.rs

@@ -246,7 +246,7 @@ impl Syntax {
         }
     }
 
-    pub fn allow_super_outside_method(self) -> bool {
+    pub(crate) fn allow_super_outside_method(self) -> bool {
         match self {
             Syntax::Es(EsConfig {
                 allow_super_outside_method,
@@ -256,6 +256,16 @@ impl Syntax {
         }
     }
 
+    pub(crate) fn allow_return_outside_function(self) -> bool {
+        match self {
+            Syntax::Es(EsConfig {
+                allow_return_outside_function,
+                ..
+            }) => allow_return_outside_function,
+            Syntax::Typescript(_) => false,
+        }
+    }
+
     pub(crate) fn early_errors(self) -> bool {
         match self {
             Syntax::Typescript(t) => !t.no_early_errors,
@@ -315,6 +325,9 @@ pub struct EsConfig {
 
     #[serde(default, rename = "allowSuperOutsideMethod")]
     pub allow_super_outside_method: bool,
+
+    #[serde(default, rename = "allowReturnOutsideFunction")]
+    pub allow_return_outside_function: bool,
 }
 
 /// Syntactic context.

crates/swc_ecma_parser/src/parser/stmt.rs

@@ -562,7 +562,7 @@ impl<'a, I: Tokens> Parser<I> {
             }))
         });
 
-        if !self.ctx().in_function {
+        if !self.ctx().in_function && !self.input.syntax().allow_return_outside_function() {
             self.emit_err(span!(self, start), SyntaxError::ReturnNotAllowed);
         }
 

crates/swc_html_minifier/src/lib.rs

@@ -1055,13 +1055,17 @@ impl Minifier {
 
     // TODO source map url output for JS and CSS?
     // TODO allow preserve comments
-    fn minify_js(&self, data: String, is_module: bool) -> Option<String> {
+    fn minify_js(&self, data: String, is_module: bool, is_attribute: bool) -> Option<String> {
         let mut errors: Vec<_> = vec![];
 
         let cm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
         let fm = cm.new_source_file(FileName::Anon, data);
 
-        let syntax = swc_ecma_parser::Syntax::Es(Default::default());
+        let syntax = swc_ecma_parser::Syntax::Es(swc_ecma_parser::EsConfig {
+            allow_return_outside_function: !is_module && is_attribute,
+            ..Default::default()
+        });
+
         let target = swc_ecma_ast::EsVersion::latest();
         let mut program = if is_module {
             match swc_ecma_parser::parse_file_as_module(&fm, syntax, target, None, &mut errors) {
@@ -1075,6 +1079,11 @@ impl Minifier {
             }
         };
 
+        // Avoid compress potential invalid JS
+        if !errors.is_empty() {
+            return None;
+        }
+
         let unresolved_mark = Mark::new();
         let top_level_mark = Mark::new();
 
@@ -1083,11 +1092,6 @@ impl Minifier {
             &mut swc_ecma_transforms_base::resolver(unresolved_mark, top_level_mark, false),
         );
 
-        // Avoid compress potential invalid JS
-        if !errors.is_empty() {
-            return None;
-        }
-
         let options = swc_ecma_minifier::option::MinifyOptions {
             compress: Some(swc_ecma_minifier::option::CompressOptions {
                 ecma: target,
@@ -1657,8 +1661,8 @@ impl VisitMut for Minifier {
             }
 
             value = values.join(" ");
-        } else if self.minify_js && self.is_event_handler_attribute(&n.name) {
-            value = match self.minify_js(value.clone(), false) {
+        } else if self.is_event_handler_attribute(&n.name) {
+            value = match self.minify_js(value.clone(), false, true) {
                 Some(minified) => minified,
                 _ => value,
             };
@@ -1681,13 +1685,13 @@ impl VisitMut for Minifier {
 
             match minifier_type {
                 Some(MinifierType::JsScript) if self.minify_js => {
-                    value = match self.minify_js(value.clone(), false) {
+                    value = match self.minify_js(value.clone(), false, true) {
                         Some(minified) => minified,
                         _ => value,
                     };
                 }
                 Some(MinifierType::JsModule) if self.minify_js => {
-                    value = match self.minify_js(value.clone(), true) {
+                    value = match self.minify_js(value.clone(), true, true) {
                         Some(minified) => minified,
                         _ => value,
                     };
@@ -1818,15 +1822,15 @@ impl VisitMut for Minifier {
 
         match text_type {
             Some(MinifierType::JsScript) => {
-                let minified = match self.minify_js(n.data.to_string(), false) {
+                let minified = match self.minify_js(n.data.to_string(), false, false) {
                     Some(minified) => minified,
                     None => return,
                 };
 
                 n.data = minified.into();
             }
             Some(MinifierType::JsModule) => {
-                let minified = match self.minify_js(n.data.to_string(), true) {
+                let minified = match self.minify_js(n.data.to_string(), true, false) {
                     Some(minified) => minified,
                     None => return,
                 };
@@ -1937,7 +1941,6 @@ fn create_minifier(context_element: Option<&Element>, options: &MinifyOptions) -
         minify_js: options.minify_js,
         minify_json: options.minify_json,
         minify_css: options.minify_css,
-
         minify_additional_attributes: options.minify_additional_attributes.clone(),
         minify_additional_scripts_content: options.minify_additional_scripts_content.clone(),
     }

crates/swc_html_minifier/tests/fixture/attribute/javascript-prefix/input.html

@@ -15,5 +15,8 @@
          style="width:100%; height:100%; position:absolute; top:0; left:0; z-index:-1;">
         <circle onmouseover="   javascript:alert('test')   " cx="50" cy="50" r="30" style="fill:url(#gradient)" />
     </svg>
+    <div type="text" onmouseover="javascript:myFunction()">test</div>
+    <a href="https://datacadamia.com" onclick="console.log(`Navigation to ${this.href}` + ` cancelled`); return false;">Click me</a>
+    <a href="https://datacadamia.com" onclick="javascript:console.log(`Navigation to ${this.href}` + ` cancelled`); return false;">Click me</a>
 </body>
 </html>

crates/swc_html_minifier/tests/fixture/attribute/javascript-prefix/output.min.html

@@ -6,4 +6,7 @@
     <div type=text>test</div>
     <svg version=1.1 viewBox="0 0 100 100" preserveAspectRatio="xMidYMid slice" style=width:100%;height:100%;position:absolute;top:0;left:0;z-index:-1>
         <circle onmouseover='alert("test")' cx=50 cy=50 r=30 style=fill:url(#gradient) />
-    </svg>
+    </svg>
+    <div type=text onmouseover=myFunction()>test</div>
+    <a href=https://datacadamia.com onclick="console.log(`Navigation to ${this.href} cancelled`);return false">Click me</a>
+    <a href=https://datacadamia.com onclick="console.log(`Navigation to ${this.href} cancelled`);return false">Click me</a>

crates/swc_html_minifier/tests/fixture/attribute/onclick/output.min.html

@@ -1,2 +1,2 @@
-<!doctype html><html lang=en><meta charset=UTF-8><meta name=viewport content="width=device-width,user-scalable=no,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0"><meta http-equiv=X-UA-Compatible content="ie=edge"><title>Document</title><a href=http://www.google.co.uk/ onclick="return (confirm('Follow' + ' this link?'))">Google</a>
+<!doctype html><html lang=en><meta charset=UTF-8><meta name=viewport content="width=device-width,user-scalable=no,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0"><meta http-equiv=X-UA-Compatible content="ie=edge"><title>Document</title><a href=http://www.google.co.uk/ onclick='return confirm("Follow this link?")'>Google</a>
 <a href=http://www.google.co.uk/ onclick='alert("testtest")'>Google</a>