Add the content of the package.

test/variables_test.dart

Index: test/variables_test.dart
diff --git a/test/variables_test.dart b/test/variables_test.dart
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+// 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';
+
+void main() {
+  test("a variable reports itself", () {
+    expect(new BooleanSelector.parse("foo").variables, equals(["foo"]));
+  });
+
+  test("a negation reports its contents", () {
+    expect(new BooleanSelector.parse("!foo").variables, equals(["foo"]));
+  });
+
+  test("a parenthesized expression reports its contents", () {
+    expect(new BooleanSelector.parse("(foo)").variables, equals(["foo"]));
+  });
+
+  test("an or reports its contents", () {
+    expect(new BooleanSelector.parse("foo || bar").variables,
+        equals(["foo", "bar"]));
+  });
+
+  test("an and reports its contents", () {
+    expect(new BooleanSelector.parse("foo && bar").variables,
+        equals(["foo", "bar"]));
+  });
+
+  test("a conditional reports its contents", () {
+    expect(new BooleanSelector.parse("foo ? bar : baz").variables,
+        equals(["foo", "bar", "baz"]));
+  });
+
+  test("BooleanSelector.all reports no variables", () {
+    expect(BooleanSelector.all.variables, isEmpty);
+  });
+
+  test("BooleanSelector.none reports no variables", () {
+    expect(BooleanSelector.none.variables, isEmpty);
+  });
+}