Lucene.Net.Search.TestDocIdSet.TestNullDocIdSet C# (CSharp) Method

        public virtual void TestNullDocIdSet()
        {
            // Tests that if a Filter produces a null DocIdSet, which is given to
            // IndexSearcher, everything works fine. this came up in LUCENE-1754.
            Directory dir = NewDirectory();
            RandomIndexWriter writer = new RandomIndexWriter(Random(), dir, Similarity, TimeZone);
            Document doc = new Document();
            doc.Add(NewStringField("c", "val", Field.Store.NO));
            writer.AddDocument(doc);
            IndexReader reader = writer.Reader;
            writer.Dispose();

            // First verify the document is searchable.
            IndexSearcher searcher = NewSearcher(reader);
            Assert.AreEqual(1, searcher.Search(new MatchAllDocsQuery(), 10).TotalHits);

            // Now search w/ a Filter which returns a null DocIdSet
            Filter f = new FilterAnonymousInnerClassHelper(this);

            Assert.AreEqual(0, searcher.Search(new MatchAllDocsQuery(), f, 10).TotalHits);
            reader.Dispose();
            dir.Dispose();
        }