Lucene.Net.Index.TestNumericDocValuesUpdates.TestUpdateOldSegments C# (CSharp) Method

        public virtual void TestUpdateOldSegments()
        {
            OLD_FORMAT_IMPERSONATION_IS_ACTIVE = true;

            Codec[] oldCodecs = new Codec[] { new Lucene40RWCodec(OLD_FORMAT_IMPERSONATION_IS_ACTIVE), new Lucene41RWCodec(OLD_FORMAT_IMPERSONATION_IS_ACTIVE), new Lucene42RWCodec(OLD_FORMAT_IMPERSONATION_IS_ACTIVE), new Lucene45RWCodec(OLD_FORMAT_IMPERSONATION_IS_ACTIVE) };
            Directory dir = NewDirectory();

            bool oldValue = OLD_FORMAT_IMPERSONATION_IS_ACTIVE;
            // create a segment with an old Codec
            IndexWriterConfig conf = NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random()));
            conf.SetCodec(oldCodecs[Random().Next(oldCodecs.Length)]);
            IndexWriter writer = new IndexWriter(dir, conf);
            Document doc = new Document();
            doc.Add(new StringField("id", "doc", Store.NO));
            doc.Add(new NumericDocValuesField("f", 5));
            writer.AddDocument(doc);
            writer.Dispose();

            conf = NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random()));
            writer = new IndexWriter(dir, conf);
            writer.UpdateNumericDocValue(new Term("id", "doc"), "f", 4L);
            OLD_FORMAT_IMPERSONATION_IS_ACTIVE = false;
            try
            {
                writer.Dispose();
                Assert.Fail("should not have succeeded to update a segment written with an old Codec");
            }
            catch (System.NotSupportedException e)
            {
                writer.Rollback();
            }
            finally
            {
                OLD_FORMAT_IMPERSONATION_IS_ACTIVE = oldValue;
            }

            dir.Dispose();
        }