public void MissingTerms_Test() { string fieldName = "field1"; RAMDirectory rd = new RAMDirectory(); IndexWriter w = new IndexWriter(rd, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.UNLIMITED); for (int i = 0; i < 100; i++) { Document doc = new Document(); int term = i * 10; //terms are units of 10; doc.Add(new Field(fieldName, "" + term, Field.Store.YES, Field.Index.NOT_ANALYZED)); w.AddDocument(doc); } w.Close(); IndexReader reader = IndexReader.Open(rd, true); TermsFilter tf = new TermsFilter(); tf.AddTerm(new Term(fieldName, "19")); OpenBitSet bits = (OpenBitSet)tf.GetDocIdSet(reader); Assert.AreEqual(0, bits.Cardinality(), "Must match nothing"); tf.AddTerm(new Term(fieldName, "20")); bits = (OpenBitSet)tf.GetDocIdSet(reader); Assert.AreEqual(1, bits.Cardinality(), "Must match 1"); tf.AddTerm(new Term(fieldName, "10")); bits = (OpenBitSet)tf.GetDocIdSet(reader); Assert.AreEqual(2, bits.Cardinality(), "Must match 2"); tf.AddTerm(new Term(fieldName, "00")); bits = (OpenBitSet)tf.GetDocIdSet(reader); Assert.AreEqual(2, bits.Cardinality(), "Must match 2"); }