message: add fuzzy merge test
diff: @@ -1104,7 +1104,7 @@ mod tests {
  use crate::schema::IntOptions;
  use crate::schema::Term;
  use crate::schema::TextFieldIndexing;
  - use crate::schema::{Cardinality, TEXT};
  + use crate::schema::{Cardinality, TEXT, STORED};
  use crate::DocAddress;
  use crate::IndexSettings;
  use crate::IndexSortByField;
  @@ -1263,6 +1263,54 @@ mod tests {
  Ok(())
  }
  + #[test]
  + fn test_fuzzy_index_merger_with_deletes() -> crate::Result<()> {
  + let mut schema_builder = schema::Schema::builder();
  + let id_field = schema_builder.add_u64_field("id", INDEXED | FAST | STORED);
  + let title_field = schema_builder.add_text_field("title", TEXT | STORED);
  + let schema = schema_builder.build();
  +
  + let index = Index::create_in_ram(schema);
  + let index_reader = index.reader().unwrap();
  + let mut index_writer = index.writer(50_000_000).unwrap();
  +
  + let create_doc = |id: u64| -> Document {
  + let mut doc = Document::default();
  + doc.add_text(title_field, format!("Hello world {}", id));
  + doc.add_u64(id_field, id);
  + doc
  + };
  +
  + let mut created = 0;
  + let mut deleted = 0;
  + let count_docs = || -> usize {
  + let searcher = index_reader.searcher();
  + searcher.search(&AllQuery, &Count).unwrap()
  + };
  +
  + for i in 0..50 {
  + let start_id = i * 1000;
  +
  + for a in 0..1000 {
  + let doc = create_doc(start_id + a);
  + index_writer.add_document(doc);
  + created += 1;
  + }
  + index_writer.commit().unwrap();
  +
  + for a in 10..980 {
  + index_writer.delete_term(Term::from_field_u64(id_field, start_id + a));
  + deleted += 1;
  + }
  + index_writer.commit().unwrap();
  + }
  +
  + index_reader.reload().unwrap();
  + assert_eq!(created - deleted, count_docs());
  +
  + Ok(())
  + }
  +
  #[test]
  fn test_index_merger_with_deletes() -> crate::Result<()> {
  let mut schema_builder = schema::Schema::builder();
  