From ce48982c6f6a0f6657008be1ebc1eacc5bda146e Mon Sep 17 00:00:00 2001
From: Dunqing <dengqing0821@gmail.com>
Date: Sat, 13 Jan 2024 19:03:50 +0800
Subject: [PATCH] feat(transformer/typescript): remove export specifier that
 import_kind is type

---
 crates/oxc_transformer/src/typescript/mod.rs | 19 +++++++++++++++----
 tasks/transform_conformance/babel.snap.md    |  6 ++----
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/crates/oxc_transformer/src/typescript/mod.rs b/crates/oxc_transformer/src/typescript/mod.rs
index bf23388a64afc..bb7f210428764 100644
--- a/crates/oxc_transformer/src/typescript/mod.rs
+++ b/crates/oxc_transformer/src/typescript/mod.rs
@@ -20,7 +20,8 @@ pub struct TypeScript<'a> {
     ast: Rc<AstBuilder<'a>>,
     ctx: TransformerCtx<'a>,
     verbatim_module_syntax: bool,
-
+    /// type imports names
+    import_type_name_set: FxHashSet<Atom>,
     export_name_set: FxHashSet<Atom>,
 }
 
@@ -30,7 +31,13 @@ impl<'a> TypeScript<'a> {
         ctx: TransformerCtx<'a>,
         verbatim_module_syntax: bool,
     ) -> Self {
-        Self { ast, ctx, verbatim_module_syntax, export_name_set: FxHashSet::default() }
+        Self {
+            ast,
+            ctx,
+            verbatim_module_syntax,
+            import_type_name_set: FxHashSet::default(),
+            export_name_set: FxHashSet::default(),
+        }
     }
 
     pub fn transform_declaration(&mut self, decl: &mut Declaration<'a>) {
@@ -101,7 +108,7 @@ impl<'a> TypeScript<'a> {
     /// * Remove the top level import / export statements that are types
     /// * Adds `export {}` if all import / export statements are removed, this is used to tell
     /// downstream tools that this file is in ESM.
-    pub fn transform_program(&self, program: &mut Program<'a>) {
+    pub fn transform_program(&mut self, program: &mut Program<'a>) {
         let mut needs_explicit_esm = false;
 
         for stmt in program.body.iter_mut() {
@@ -109,13 +116,17 @@ impl<'a> TypeScript<'a> {
                 needs_explicit_esm = true;
                 match &mut **module_decl {
                     ModuleDeclaration::ExportNamedDeclaration(decl) => {
-                        decl.specifiers.retain(|specifier| specifier.export_kind.is_value());
+                        decl.specifiers.retain(|specifier| {
+                            !(specifier.export_kind.is_type()
+                                || self.import_type_name_set.contains(specifier.exported.name()))
+                        });
                     }
                     ModuleDeclaration::ImportDeclaration(decl) if decl.import_kind.is_value() => {
                         if let Some(specifiers) = &mut decl.specifiers {
                             specifiers.retain(|specifier| match specifier {
                                 ImportDeclarationSpecifier::ImportSpecifier(s) => {
                                     if s.import_kind.is_type() {
+                                        self.import_type_name_set.insert(s.local.name.clone());
                                         return false;
                                     }
 
diff --git a/tasks/transform_conformance/babel.snap.md b/tasks/transform_conformance/babel.snap.md
index c7f281a97c0dd..66f8f908d12b1 100644
--- a/tasks/transform_conformance/babel.snap.md
+++ b/tasks/transform_conformance/babel.snap.md
@@ -1,4 +1,4 @@
-Passed: 304/1179
+Passed: 306/1179
 
 # All Passed:
 * babel-plugin-transform-numeric-separator
@@ -832,7 +832,7 @@ Passed: 304/1179
 * general/function-duplicate-name/input.js
 * general/object/input.js
 
-# babel-plugin-transform-typescript (73/158)
+# babel-plugin-transform-typescript (75/158)
 * class/abstract-class-decorated/input.ts
 * class/abstract-class-decorated-method/input.ts
 * class/abstract-class-decorated-parameter/input.ts
@@ -872,9 +872,7 @@ Passed: 304/1179
 * imports/import=-module-to-cjs/input.ts
 * imports/only-remove-type-imports/input.ts
 * imports/parameter-decorators/input.ts
-* imports/type-only-export-specifier-1/input.ts
 * imports/type-only-export-specifier-2/input.ts
-* imports/type-only-import-specifier-3/input.ts
 * imports/type-only-import-specifier-4/input.ts
 * namespace/ambient-module-nested/input.ts
 * namespace/ambient-module-nested-exported/input.ts