[ts] Fix compiling extended exported nested namespace (#15798)

babel · Jul 20, 2023 · 12dfea7 · 12dfea7
1 parent 3caeeb1
commit 12dfea7
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Showing 4 changed files with 43 additions and 10 deletions.
diff --git a/packages/babel-plugin-transform-typescript/src/index.ts b/packages/babel-plugin-transform-typescript/src/index.ts
@@ -460,6 +460,29 @@ export default declare((api, opts: Options) => {
           return;
         }
 
+        // Convert `export namespace X {}` into `export let X; namespace X {}`,
+        // so that when visiting TSModuleDeclaration we do not have to possibly
+        // replace its parent path.
+        if (t.isTSModuleDeclaration(path.node.declaration)) {
+          const namespace = path.node.declaration;
+          const { id } = namespace;
+          if (t.isIdentifier(id)) {
+            if (path.scope.hasOwnBinding(id.name)) {
+              path.replaceWith(namespace);
+            } else {
+              const [newExport] = path.replaceWithMultiple([
+                t.exportNamedDeclaration(
+                  t.variableDeclaration("let", [
+                    t.variableDeclarator(t.cloneNode(id)),
+                  ]),
+                ),
+                namespace,
+              ]);
+              path.scope.registerDeclaration(newExport);
+            }
+          }
+        }
+
         NEEDS_EXPLICIT_ESM.set(state.file.ast.program, false);
       },
 

diff --git a/packages/babel-plugin-transform-typescript/src/namespace.ts b/packages/babel-plugin-transform-typescript/src/namespace.ts
@@ -23,16 +23,7 @@ export default function transpileNamespace(
 
   const name = path.node.id.name;
   const value = handleNested(path, t.cloneNode(path.node, true));
-  const bound = path.scope.hasOwnBinding(name);
-  if (path.parent.type === "ExportNamedDeclaration") {
-    if (!bound) {
-      path.parentPath.insertAfter(value);
-      path.replaceWith(getDeclaration(name));
-      path.scope.registerDeclaration(path.parentPath);
-    } else {
-      path.parentPath.replaceWith(value);
-    }
-  } else if (bound) {
+  if (path.scope.hasOwnBinding(name)) {
     path.replaceWith(value);
   } else {
     path.scope.registerDeclaration(

diff --git a/...abel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand-export/input.ts b/...abel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand-export/input.ts
@@ -0,0 +1,6 @@
+export namespace ui.a {
+  export const x = 1;
+}
+export namespace ui.b {
+  export const y = 2;
+}
diff --git a/...el-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand-export/output.mjs b/...el-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand-export/output.mjs
@@ -0,0 +1,13 @@
+export let ui;
+(function (_ui2) {
+  let a;
+  (function (_a) {
+    const x = _a.x = 1;
+  })(a || (a = _ui2.a || (_ui2.a = {})));
+})(ui || (ui = {}));
+(function (_ui) {
+  let b;
+  (function (_b) {
+    const y = _b.y = 2;
+  })(b || (b = _ui.b || (_ui.b = {})));
+})(ui || (ui = {}));