feat(es/compat): Support export class from stage 3 decorator pass (#…

…7363)

**Related issue:**

 - Closes #7358.

crates/swc_ecma_ast/src/decl.rs

@@ -86,6 +86,16 @@ pub struct ClassDecl {
     pub class: Box<Class>,
 }
 
+impl Take for ClassDecl {
+    fn dummy() -> Self {
+        ClassDecl {
+            ident: Take::dummy(),
+            declare: Default::default(),
+            class: Take::dummy(),
+        }
+    }
+}
+
 #[ast_node("VariableDeclaration")]
 #[derive(Eq, Hash, EqIgnoreSpan)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]

crates/swc_ecma_transforms_proposal/tests/decorators.rs

@@ -18,6 +18,7 @@ fn syntax_default() -> Syntax {
         decorators: true,
         auto_accessors: true,
         allow_super_outside_method: true,
+        decorators_before_export: true,
         ..Default::default()
     })
 }

crates/swc_ecma_transforms_proposal/tests/decorators/issue-7358/1/input.js

@@ -0,0 +1,19 @@
+@decorate()
+export class Foo {
+
+    @decorate()
+    get name() {
+        return "hello"
+    }
+
+    @decorate()
+    sayHi() {
+        return "hello"
+    }
+}
+
+function decorate() {
+    return function (target, { kind }) {
+        console.log(target, kind)
+    }
+}

crates/swc_ecma_transforms_proposal/tests/decorators/issue-7358/1/options.json

@@ -0,0 +1,3 @@
+{
+    "plugins": [["proposal-decorators", { "version": "2022-03" }]]
+}

crates/swc_ecma_transforms_proposal/tests/decorators/issue-7358/1/output.js

@@ -0,0 +1,39 @@
+var _dec, _initClass, _dec1, _dec2, _initProto;
+let _Foo;
+_dec = decorate(), _dec1 = decorate(), _dec2 = decorate();
+class Foo {
+    static{
+        ({ e: [_initProto] , c: [_Foo, _initClass]  } = _apply_decs_2203_r(this, [
+            [
+                _dec1,
+                3,
+                "name"
+            ],
+            [
+                _dec2,
+                2,
+                "sayHi"
+            ]
+        ], [
+            _dec
+        ]));
+    }
+    constructor(){
+        _initProto(this);
+    }
+    get name() {
+        return "hello";
+    }
+    sayHi() {
+        return "hello";
+    }
+    static{
+        _initClass();
+    }
+}
+function decorate() {
+    return function(target, { kind  }) {
+        console.log(target, kind);
+    };
+}
+export { _Foo as Foo };

crates/swc_ecma_utils/src/lib.rs

@@ -2949,6 +2949,25 @@ impl VisitMut for IdentRenamer<'_> {
             node.span.ctxt = new.1;
         }
     }
+
+    fn visit_mut_export_named_specifier(&mut self, node: &mut ExportNamedSpecifier) {
+        if node.exported.is_some() {
+            node.orig.visit_mut_children_with(self);
+            return;
+        }
+
+        match &mut node.orig {
+            ModuleExportName::Ident(orig) => {
+                if let Some(new) = self.map.get(&orig.to_id()) {
+                    node.exported = Some(ModuleExportName::Ident(orig.clone()));
+
+                    orig.sym = new.0.clone();
+                    orig.span.ctxt = new.1;
+                }
+            }
+            ModuleExportName::Str(_) => {}
+        }
+    }
 }
 
 #[cfg(test)]