Add tests and basic support for batch exports.

lib/exports.js

@@ -52,10 +52,7 @@ ExportDeclarationList.prototype.declarationForNode = function(node) {
   } else if (n.FunctionDeclaration.check(node.declaration)) {
     return new FunctionExportDeclaration(this.module, node);
   } else if (n.ExportBatchSpecifier.check(node.specifiers[0])) {
-    throw new Error(
-      '`export *` found at ' + sourcePosition(this.module, node) +
-      ' is not supported, please use `export { … }` instead'
-    );
+    return new BatchExportDeclaration(this.module, node);
   } else {
     return new NamedExportDeclaration(this.module, node);
   }
@@ -225,6 +222,25 @@ memo(FunctionExportDeclaration.prototype, 'specifiers', /** @this FunctionExport
   return [new ExportSpecifier(this, this.node.declaration)];
 });
 
+/**
+ * Represents an batch export declaration.
+ *
+ * @constructor
+ * @extends ExportDeclaration
+ * @param {Module} mod
+ * @param {AST.ExportDeclaration} node
+ */
+function BatchExportDeclaration(mod, node) {
+  ExportDeclaration.call(this, mod, node);
+}
+extend(BatchExportDeclaration, ExportDeclaration);
+
+memo(BatchExportDeclaration.prototype, 'specifiers', /** @this BatchExportDeclaration */function() {
+  return this.source.exports.declarations.reduce(function(specifiers, declaration) {
+    return specifiers.concat(declaration.specifiers);
+  }, []);
+});
+
 /**
  * Represents an export specifier in an export declaration.
  *

test/examples/batch-export/first.js

@@ -0,0 +1,5 @@
+/* jshint esnext:true */
+
+export var a = 1;
+export var b = 2;
+export var c = 3;

test/examples/batch-export/second.js

@@ -0,0 +1,4 @@
+/* jshint esnext:true */
+
+export var c = 99;
+export * from './first';

test/examples/batch-export/third.js

@@ -0,0 +1,7 @@
+/* jshint esnext:true */
+
+import { a, b, c } from './second';
+
+assert.strictEqual(a, 1);
+assert.strictEqual(b, 2);
+assert.strictEqual(c, 99);