fix export of parameters when renaming the binding of exported functions - fixes #2753

packages/babel-core/test/fixtures/transformation/spec.function-name/modules-4/actual.js

@@ -0,0 +1,9 @@
+export function foo(bar) {
+
+}
+
+var bar = {
+  foo: function () {
+    foo;
+  }
+};

packages/babel-core/test/fixtures/transformation/spec.function-name/modules-4/expected.js

@@ -0,0 +1,8 @@
+export { _foo as foo };
+function _foo(bar) {}
+
+var bar = {
+  foo: function foo() {
+    _foo;
+  }
+};

packages/babel-traverse/src/path/family.js

@@ -123,3 +123,7 @@ export function _getPattern(parts, context) {
 export function getBindingIdentifiers(duplicates?) {
   return t.getBindingIdentifiers(this.node, duplicates);
 }
+
+export function getOuterBindingIdentifiers(duplicates?) {
+  return t.getOuterBindingIdentifiers(this.node, duplicates);
+}

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

@@ -42,7 +42,7 @@ export default class Renamer {
 
     // build specifiers that point back to this export declaration
     let isDefault = exportDeclar.isExportDefaultDeclaration();
-    let bindingIdentifiers = parentDeclar.getBindingIdentifiers();
+    let bindingIdentifiers = parentDeclar.getOuterBindingIdentifiers();
     let specifiers = [];
 
     for (let name in bindingIdentifiers) {
@@ -80,7 +80,7 @@ export default class Renamer {
 
   maybeConvertFromClassFunctionExpression(path) {
     return; // TODO
-    
+
     // retain the `name` of a class/function expression
 
     if (!path.isFunctionExpression() && !path.isClassExpression()) return;

packages/babel-types/src/retrievers.js

@@ -91,3 +91,21 @@ getBindingIdentifiers.keys = {
   VariableDeclaration: ["declarations"],
   VariableDeclarator: ["id"]
 };
+
+export function getOuterBindingIdentifiers(
+  node: Object,
+  duplicates?: boolean,
+): Object {
+  if (t.isFunction(node)) {
+    let id = node.id;
+    if (id) {
+      return {
+        [id.name]: duplicates ? [id] : id
+      };
+    } else {
+      return {};
+    }
+  } else {
+    return getBindingIdentifiers(node, duplicates);
+  }
+}