public virtual void TestDeleteAllIsCurrent()
{
// get reader
DirectoryReader reader = Writer.GetReader();
// assert index has a document and reader is up2date
Assert.AreEqual(1, Writer.NumDocs, "One document should be in the index");
Assert.IsTrue(reader.IsCurrent(), "Document added, reader should be stale ");
// remove all documents
Writer.DeleteAll();
Writer.Commit();
// assert document has been deleted (index changed), reader is stale
Assert.AreEqual(0, Writer.NumDocs, "Document should be removed");
Assert.IsFalse(reader.IsCurrent(), "Reader should be stale");
reader.Dispose();
}