Fix: export default arrows with function naming (babel#4524)

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-2/actual.js

@@ -0,0 +1,3 @@
+export default () => ({
+  x: ({x}) => {}
+})

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-2/expected.js

@@ -0,0 +1,13 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports.default = function () {
+  return {
+    x: function x(_ref) {
+      var _x = _ref.x;
+    }
+  };
+};

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-2/options.json

@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015"]
+}

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-3/actual.js

@@ -0,0 +1,4 @@
+export default ({ onClick }) => (
+  <div onClick={() => onClick()} />
+)
+

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-3/expected.js

@@ -0,0 +1,12 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports.default = function (_ref) {
+  var _onClick = _ref.onClick;
+  return React.createElement("div", { onClick: function onClick() {
+      return _onClick();
+    } });
+};

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-3/options.json

@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015", "react"]
+}

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-es3/actual.js

@@ -0,0 +1,3 @@
+export default (a) => {
+  return { a() { return a } };
+}

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-es3/expected.js

@@ -0,0 +1,13 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports["default"] = function (_a) {
+  return {
+    a: function a() {
+      return _a;
+    }
+  };
+};

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming-es3/options.json

@@ -0,0 +1,7 @@
+{
+  "presets": ["es2015"],
+  "plugins": [
+    "transform-es3-member-expression-literals",
+    "transform-es3-property-literals"
+  ]
+}

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming/actual.js

@@ -0,0 +1,3 @@
+export default (a) => {
+  return { a() { return a } };
+}

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming/expected.js

@@ -0,0 +1,13 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports.default = function (_a) {
+  return {
+    a: function a() {
+      return _a;
+    }
+  };
+};

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/export-default-arrow-renaming/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-es2015-function-name", "transform-es2015-shorthand-properties", "transform-es2015-arrow-functions", "transform-es2015-modules-commonjs"]
+}

packages/babel-traverse/src/scope/lib/renamer.js

@@ -57,15 +57,17 @@ export default class Renamer {
       specifiers.push(t.exportSpecifier(t.identifier(localName), t.identifier(exportedName)));
     }
 
-    let aliasDeclar = t.exportNamedDeclaration(null, specifiers);
+    if (specifiers.length) {
+      let aliasDeclar = t.exportNamedDeclaration(null, specifiers);
 
-    // hoist to the top if it's a function
-    if (parentDeclar.isFunctionDeclaration()) {
-      aliasDeclar._blockHoist = 3;
-    }
+      // hoist to the top if it's a function
+      if (parentDeclar.isFunctionDeclaration()) {
+        aliasDeclar._blockHoist = 3;
+      }
 
-    exportDeclar.insertAfter(aliasDeclar);
-    exportDeclar.replaceWith(parentDeclar.node);
+      exportDeclar.insertAfter(aliasDeclar);
+      exportDeclar.replaceWith(parentDeclar.node);
+    }
   }
 
   maybeConvertFromClassFunctionDeclaration(path) {