Add the content of the package.

test/validate_test.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:test/test.dart';
+
+import 'package:boolean_selector/boolean_selector.dart';
+
+var _selector = new BooleanSelector.parse("foo && bar && baz");
+
+void main() {
+  test("throws if any variables are undefined", () {
+    expect(() => _selector.validate((variable) => variable == "bar"),
+        throwsFormatException);
+  });
+
+  test("doesn't throw if all variables are defined", () {
+    // Should not throw.
+    _selector.validate((variable) => true);
+  });
+}