public void CanIsFalse() { var env = new StandardEnvironment(); // null and false are "falsy", all other values are "truthy" // Generally, IsFalse(x) != IsTrue(x) for all x except null. Assert.IsFalse(env.IsFalse(null)); Assert.IsTrue(env.IsFalse(false)); Assert.IsFalse(env.IsFalse(true)); Assert.IsFalse(env.IsFalse(0.0)); Assert.IsFalse(env.IsFalse(-2.5)); Assert.IsFalse(env.IsFalse(string.Empty)); Assert.IsFalse(env.IsFalse("foo")); }