Lucene.Net.Search.TestSort.TestEmptyStringVsNullStringSort C# (CSharp) Метод

        public virtual void TestEmptyStringVsNullStringSort()
        {
            Directory dir = NewDirectory();
            IndexWriter w = new IndexWriter(dir, NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random())));
            Document doc = new Document();
            doc.Add(NewStringField("f", "", Field.Store.NO));
            doc.Add(NewStringField("t", "1", Field.Store.NO));
            w.AddDocument(doc);
            w.Commit();
            doc = new Document();
            doc.Add(NewStringField("t", "1", Field.Store.NO));
            w.AddDocument(doc);

            IndexReader r = DirectoryReader.Open(w, true);
            w.Dispose();
            IndexSearcher s = NewSearcher(r);
            TopDocs hits = s.Search(new TermQuery(new Term("t", "1")), null, 10, new Sort(new SortField("f", SortField.Type_e.STRING)));
            Assert.AreEqual(2, hits.TotalHits);
            // null sorts first
            Assert.AreEqual(1, hits.ScoreDocs[0].Doc);
            Assert.AreEqual(0, hits.ScoreDocs[1].Doc);
            r.Dispose();
            dir.Dispose();
        }