diff --git a/src/core/index.rs b/src/core/index.rs
index cffa15f08b..bf181713e7 100644
--- a/src/core/index.rs
+++ b/src/core/index.rs
@@ -781,24 +781,24 @@ mod tests {
         for i in 0u64..8_000u64 {
             writer.add_document(doc!(field => i))?;
         }
-        let (sender, receiver) = crossbeam::channel::unbounded();
-        let _handle = directory.watch(WatchCallback::new(move || {
-            let _ = sender.send(());
-        }));
+
         writer.commit()?;
         let mem_right_after_commit = directory.total_mem_usage();
-        assert!(receiver.recv().is_ok());
+
         let reader = index
             .reader_builder()
             .reload_policy(ReloadPolicy::Manual)
             .try_into()?;
-
         assert_eq!(reader.searcher().num_docs(), 8_000);
+        assert_eq!(reader.searcher().segment_readers().len(), 8);
+
         writer.wait_merging_threads()?;
+
         let mem_right_after_merge_finished = directory.total_mem_usage();
 
         reader.reload().unwrap();
         let searcher = reader.searcher();
+        assert_eq!(searcher.segment_readers().len(), 1);
         assert_eq!(searcher.num_docs(), 8_000);
         assert!(
             mem_right_after_merge_finished < mem_right_after_commit,
diff --git a/src/future_result.rs b/src/future_result.rs
index b3c66cae4e..d1d43f7e28 100644
--- a/src/future_result.rs
+++ b/src/future_result.rs
@@ -105,6 +105,7 @@ mod tests {
     }
 
     #[test]
+
     fn test_scheduled_result_error() {
         let (scheduled_result, tx): (FutureResult<()>, _) = FutureResult::create("failed");
         drop(tx);
diff --git a/src/indexer/segment_updater.rs b/src/indexer/segment_updater.rs
index 61d98412ef..9b51440fb4 100644
--- a/src/indexer/segment_updater.rs
+++ b/src/indexer/segment_updater.rs
@@ -539,17 +539,17 @@ impl SegmentUpdater {
                 merge_operation.target_opstamp(),
             ) {
                 Ok(after_merge_segment_entry) => {
-                    let segment_meta =
+                    let segment_meta_res =
                         segment_updater.end_merge(merge_operation, after_merge_segment_entry);
-                    let _send_result = merging_future_send.send(segment_meta);
+                    let _send_result = merging_future_send.send(segment_meta_res);
                 }
-                Err(e) => {
+                Err(merge_error) => {
                     warn!(
                         "Merge of {:?} was cancelled: {:?}",
                         merge_operation.segment_ids().to_vec(),
-                        e
+                        merge_error
                     );
-                    // ... cancel merge
+                    let _send_result = merging_future_send.send(Err(merge_error));
                     assert!(!cfg!(test), "Merge failed.");
                 }
             }
diff --git a/src/tokenizer/ascii_folding_filter.rs b/src/tokenizer/ascii_folding_filter.rs
index 56b4dfac77..21103e7776 100644
--- a/src/tokenizer/ascii_folding_filter.rs
+++ b/src/tokenizer/ascii_folding_filter.rs
@@ -1625,9 +1625,9 @@ mod tests {
 
     #[test]
     fn test_to_ascii() {
-        let mut input = "Rámon".to_string();
+        let input = "Rámon".to_string();
         let mut buffer = String::new();
-        to_ascii(&mut input, &mut buffer);
+        to_ascii(&input, &mut buffer);
         assert_eq!("Ramon", buffer);
     }