Lucene.Net.Search.TestFieldCacheRangeFilter.TestSparseIndex C# (CSharp) Method

        public virtual void TestSparseIndex()
        {
            Directory dir = NewDirectory();
            IndexWriter writer = new IndexWriter(dir, NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random())));

            for (int d = -20; d <= 20; d++)
            {
                Document doc = new Document();
                doc.Add(NewStringField("id", Convert.ToString(d), Field.Store.NO));
                doc.Add(NewStringField("body", "body", Field.Store.NO));
                writer.AddDocument(doc);
            }

            writer.ForceMerge(1);
            writer.DeleteDocuments(new Term("id", "0"));
            writer.Dispose();

            IndexReader reader = DirectoryReader.Open(dir);
            IndexSearcher search = NewSearcher(reader);
            Assert.IsTrue(reader.HasDeletions);

            ScoreDoc[] result;
            Query q = new TermQuery(new Term("body", "body"));

            result = search.Search(q, FieldCacheRangeFilter.NewByteRange("id", (sbyte?)-20, (sbyte?)20, T, T), 100).ScoreDocs;
            Assert.AreEqual(40, result.Length, "find all");

            result = search.Search(q, FieldCacheRangeFilter.NewByteRange("id", (sbyte?)0, (sbyte?)20, T, T), 100).ScoreDocs;
            Assert.AreEqual(20, result.Length, "find all");

            result = search.Search(q, FieldCacheRangeFilter.NewByteRange("id", (sbyte?)-20, (sbyte?)0, T, T), 100).ScoreDocs;
            Assert.AreEqual(20, result.Length, "find all");

            result = search.Search(q, FieldCacheRangeFilter.NewByteRange("id", (sbyte?)10, (sbyte?)20, T, T), 100).ScoreDocs;
            Assert.AreEqual(11, result.Length, "find all");

            result = search.Search(q, FieldCacheRangeFilter.NewByteRange("id", (sbyte?)-20, (sbyte?)-10, T, T), 100).ScoreDocs;
            Assert.AreEqual(11, result.Length, "find all");
            reader.Dispose();
            dir.Dispose();
        }