fix(es/typescript): Mark A as a type in export { type A } (#7196)

crates/swc_ecma_transforms_typescript/src/strip.rs

@@ -165,7 +165,8 @@ pub fn strip_with_config(config: Config, top_level_mark: Mark) -> impl Fold + Vi
             is_type_only_export: Default::default(),
             decl_names: Default::default(),
             in_var_pat: Default::default(),
-            keys: Default::default()
+            keys: Default::default(),
+            exported_variable_to_is_type: Default::default(),
         }),
         inline_enum(ts_enum_lit, ts_enum_config)
     )
@@ -236,6 +237,7 @@ where
             decl_names: Default::default(),
             in_var_pat: Default::default(),
             keys: Default::default(),
+            exported_variable_to_is_type: Default::default(),
         }),
         inline_enum(ts_enum_lit, ts_enum_config)
     )
@@ -292,6 +294,10 @@ where
     in_var_pat: bool,
 
     keys: Vec<VarDeclarator>,
+
+    /// Key is the `orig` in ExportNamedSpecifier
+    /// Value is `true` if the Key is a type
+    exported_variable_to_is_type: AHashMap<Id, bool>,
 }
 
 impl<C> Strip<C>
@@ -1675,6 +1681,24 @@ where
         self.is_type_only_export = old;
     }
 
+    fn visit_export_named_specifier(&mut self, n: &ExportNamedSpecifier) {
+        let is_type = self.is_type_only_export || n.is_type_only;
+        if let ModuleExportName::Ident(local_ident) = &n.orig {
+            // If the stored exported `Id` is a value, we just leave it here.
+            // If the stored exported `Id` is both a type and value, we consider it's a
+            // value. See https://github.com/denoland/deno/issues/8978
+            let is_type_to_the_existed = self
+                .exported_variable_to_is_type
+                .entry(local_ident.to_id())
+                .or_insert(is_type);
+
+            if *is_type_to_the_existed && !is_type {
+                *is_type_to_the_existed = false
+            }
+        }
+        n.visit_children_with(self)
+    }
+
     fn visit_prop_name(&mut self, n: &PropName) {
         if let PropName::Computed(e) = n {
             e.visit_with(self)
@@ -2057,8 +2081,18 @@ where
 
         import.specifiers.retain(|s| match *s {
             ImportSpecifier::Named(ImportNamedSpecifier {
-                ref is_type_only, ..
-            }) if *is_type_only => false,
+                ref is_type_only,
+                ref local,
+                ..
+            }) if *is_type_only
+                || self
+                    .exported_variable_to_is_type
+                    .get(&local.to_id())
+                    .copied()
+                    .unwrap_or_default() =>
+            {
+                false
+            }
 
             ImportSpecifier::Default(ImportDefaultSpecifier { ref local, .. })
             | ImportSpecifier::Named(ImportNamedSpecifier { ref local, .. })

crates/swc_ecma_transforms_typescript/tests/fixture/issue-7076/1/input.ts

@@ -0,0 +1,2 @@
+import { A } from "./a.ts";
+export { type A };