public void TestUpdate() { var index = new WordIndex(); index.Update(null, new List <string>(), "w1", new List <string> { "attr1" }); Assert.That(index.GetAttributes(), Is.EquivalentTo(new string[] { "attr1" })); Assert.That(index.GetWordNames("attr1"), Is.EquivalentTo(new string[] { "w1" })); index.Update("w1", new List <string> { "attr1" }, "w1", new List <string> { "attr2", "attr3" }); Assert.That(index.GetAttributes(), Is.EquivalentTo(new string[] { "attr2", "attr3" })); Assert.That(index.GetWordNames("attr1"), Is.EquivalentTo(new string[0])); Assert.That(index.GetWordNames("attr2"), Is.EquivalentTo(new string[] { "w1" })); Assert.That(index.GetWordNames("attr3"), Is.EquivalentTo(new string[] { "w1" })); index.Update("w1", new List <string> { "attr2", "attr3" }, "w2", new List <string> { "attr3", "attr1" }); Assert.That(index.GetAttributes(), Is.EquivalentTo(new string[] { "attr1", "attr3" })); Assert.That(index.GetWordNames("attr1"), Is.EquivalentTo(new string[] { "w2" })); Assert.That(index.GetWordNames("attr2"), Is.EquivalentTo(new string[0])); Assert.That(index.GetWordNames("attr3"), Is.EquivalentTo(new string[] { "w2" })); }