fix: register inserted class declaration

packages/babel-plugin-proposal-decorators/src/transformer-legacy.js

@@ -237,15 +237,18 @@ export default {
 
     const replacement = decoratedClassToExpression(decl);
     if (replacement) {
-      path.replaceWithMultiple([
-        replacement,
+      path.replaceWith(replacement);
+      path.insertAfter(
         t.exportNamedDeclaration(null, [
           t.exportSpecifier(
             t.cloneNode(replacement.declarations[0].id),
             t.identifier("default"),
           ),
         ]),
-      ]);
+      );
+      if (!decl.node.id) {
+        path.scope.registerDeclaration(path.get("declarations.0"));
+      }
     }
   },
   ClassDeclaration(path) {

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-decl-to-expression/class-decorators/output.mjs

@@ -1,7 +1,7 @@
 var _class, _class2;
 
-let A = dec(_class2 = class A {}) || _class2;
+let A = dec(_class = class A {}) || _class;
 
 export { A as default };
 
-let B = dec(_class = class B {}) || _class;
+let B = dec(_class2 = class B {}) || _class2;

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-decl-to-expression/method-decorators/output.mjs

@@ -2,12 +2,12 @@ var _class, _class2;
 
 function _applyDecoratedDescriptor(target, property, decorators, descriptor, context) { var desc = {}; Object.keys(descriptor).forEach(function (key) { desc[key] = descriptor[key]; }); desc.enumerable = !!desc.enumerable; desc.configurable = !!desc.configurable; if ('value' in desc || desc.initializer) { desc.writable = true; } desc = decorators.slice().reverse().reduce(function (desc, decorator) { return decorator(target, property, desc) || desc; }, desc); if (context && desc.initializer !== void 0) { desc.value = desc.initializer ? desc.initializer.call(context) : void 0; desc.initializer = undefined; } if (desc.initializer === void 0) { Object.defineProperty(target, property, desc); desc = null; } return desc; }
 
-let A = (_class2 = class A {
+let A = (_class = class A {
   foo() {}
 
-}, (_applyDecoratedDescriptor(_class2.prototype, "foo", [dec], Object.getOwnPropertyDescriptor(_class2.prototype, "foo"), _class2.prototype)), _class2);
+}, (_applyDecoratedDescriptor(_class.prototype, "foo", [dec], Object.getOwnPropertyDescriptor(_class.prototype, "foo"), _class.prototype)), _class);
 export { A as default };
-let B = (_class = class B {
+let B = (_class2 = class B {
   foo() {}
 
-}, (_applyDecoratedDescriptor(_class.prototype, "foo", [dec], Object.getOwnPropertyDescriptor(_class.prototype, "foo"), _class.prototype)), _class);
+}, (_applyDecoratedDescriptor(_class2.prototype, "foo", [dec], Object.getOwnPropertyDescriptor(_class2.prototype, "foo"), _class2.prototype)), _class2);

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-regression/10264/input.mjs

@@ -0,0 +1,4 @@
+function myDecorator(decoratee) {}
+
+@myDecorator
+export default class {}

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-regression/10264/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    "transform-typescript",
+    [ "proposal-decorators", { "legacy": true } ]
+  ]
+}

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-regression/10264/output.mjs

@@ -0,0 +1,7 @@
+var _class2;
+
+function myDecorator(decoratee) {}
+
+let _class = myDecorator(_class2 = class {}) || _class2;
+
+export { _class as default };