feat(codegen): correctly print type-only imports/exports (#2993)

oxc-project · Apr 15, 2024 · fd5002b · fd5002b
1 parent 82e00bc
commit fd5002b
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 0 deletions.
diff --git a/crates/oxc_codegen/src/gen.rs b/crates/oxc_codegen/src/gen.rs
@@ -724,6 +724,9 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for ImportDeclaration<'a> {
     fn gen(&self, p: &mut Codegen<{ MINIFY }>, ctx: Context) {
         p.add_source_mapping(self.span.start);
         p.print_str(b"import ");
+        if p.options.enable_typescript && self.import_kind.is_type() {
+            p.print_str(b"type ");
+        }
         if let Some(specifiers) = &self.specifiers {
             if specifiers.is_empty() {
                 p.print(b'\'');
@@ -770,6 +773,10 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for ImportDeclaration<'a> {
                             p.print(b'{');
                         }
 
+                        if p.options.enable_typescript && spec.import_kind.is_type() {
+                            p.print_str(b"type ");
+                        }
+
                         let imported_name = match &spec.imported {
                             ModuleExportName::Identifier(identifier) => {
                                 identifier.gen(p, ctx);
@@ -842,6 +849,9 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for ExportNamedDeclaration<'a> {
             return;
         }
         p.print_str(b"export ");
+        if p.options.enable_typescript && self.export_kind.is_type() {
+            p.print_str(b"type ");
+        }
         match &self.declaration {
             Some(decl) => decl.gen(p, ctx),
             None => {
@@ -866,6 +876,9 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for ExportNamedDeclaration<'a> {
 
 impl<'a, const MINIFY: bool> Gen<MINIFY> for ExportSpecifier<'a> {
     fn gen(&self, p: &mut Codegen<{ MINIFY }>, ctx: Context) {
+        if p.options.enable_typescript && self.export_kind.is_type() {
+            p.print_str(b"type ");
+        }
         self.local.gen(p, ctx);
         if self.local.name() != self.exported.name() {
             p.print_str(b" as ");
@@ -892,6 +905,9 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for ExportAllDeclaration<'a> {
             return;
         }
         p.print_str(b"export ");
+        if p.options.enable_typescript && self.export_kind.is_type() {
+            p.print_str(b"type ");
+        }
         p.print(b'*');
 
         if let Some(exported) = &self.exported {

diff --git a/crates/oxc_codegen/tests/mod.rs b/crates/oxc_codegen/tests/mod.rs
@@ -162,4 +162,9 @@ fn typescript() {
     test_ts("let x: string['length'] = 123;", "let x: string['length'] = 123;\n", false);
 
     test_ts("function isString(value: unknown): asserts value is string {\n\tif (typeof value !== 'string') {\n\t\tthrow new Error('Not a string');\n\t}\n}", "function isString(value: unknown): asserts value is string {\n\tif (typeof value !== 'string') {\n\t\tthrow new Error('Not a string');\n\t}\n}\n", false);
+
+    // type-only imports/exports
+    test_ts("import type { Foo } from 'foo';", "import type {Foo} from 'foo';\n", false);
+    test_ts("import { Foo, type Bar } from 'foo';", "import {Foo,type Bar} from 'foo';\n", false);
+    test_ts("export { Foo, type Bar } from 'foo';", "export { Foo, type Bar } from 'foo';", false);
 }