From 443aa1732905264161b953c33cb944be2f5142e0 Mon Sep 17 00:00:00 2001
From: Hardik Prajapati <hardikpnsp@gmail.com>
Date: Wed, 7 Apr 2021 23:10:48 +0530
Subject: [PATCH 1/4] AAdded failing test for tie scenario in topk

---
 src/collector/facet_collector.rs | 39 ++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/collector/facet_collector.rs b/src/collector/facet_collector.rs
index 0e6432d5f..077da6b0f 100644
--- a/src/collector/facet_collector.rs
+++ b/src/collector/facet_collector.rs
@@ -657,6 +657,45 @@ mod tests {
             );
         }
     }
+
+    #[test]
+    fn test_facet_collector_topk_tie_break() {
+        let mut schema_builder = Schema::builder();
+        let facet_field = schema_builder.add_facet_field("facet", INDEXED);
+        let schema = schema_builder.build();
+        let index = Index::create_in_ram(schema);
+
+        let docs: Vec<Document> = vec![("b", 2), ("a", 2), ("c", 4)]
+            .into_iter()
+            .flat_map(|(c, count)| {
+                let facet = Facet::from(&format!("/facet/{}", c));
+                let doc = doc!(facet_field => facet);
+                iter::repeat(doc).take(count)
+            })
+            .collect();
+
+        let mut index_writer = index.writer_for_tests().unwrap();
+        for doc in docs {
+            index_writer.add_document(doc);
+        }
+        index_writer.commit().unwrap();
+        let searcher = index.reader().unwrap().searcher();
+
+        let mut facet_collector = FacetCollector::for_field(facet_field);
+        facet_collector.add_facet("/facet");
+        let counts: FacetCounts = searcher.search(&AllQuery, &facet_collector).unwrap();
+
+        {
+            let facets: Vec<(&Facet, u64)> = counts.top_k("/facet", 2);
+            assert_eq!(
+                facets,
+                vec![
+                    (&Facet::from("/facet/c"), 4),
+                    (&Facet::from("/facet/a"), 2),
+                ]
+            );
+        }
+    }
 }
 
 #[cfg(all(test, feature = "unstable"))]

From 50eea4376b256974f28786a62caa440b599897df Mon Sep 17 00:00:00 2001
From: Hardik Prajapati <hardikpnsp@gmail.com>
Date: Wed, 7 Apr 2021 23:14:38 +0530
Subject: [PATCH 2/4] Implementation of Ord trait changed for Hit

- This will result in lexicographical ordering of facet in BinaryHeep in case of a tie
---
 src/collector/facet_collector.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/collector/facet_collector.rs b/src/collector/facet_collector.rs
index 077da6b0f..108a5d1f3 100644
--- a/src/collector/facet_collector.rs
+++ b/src/collector/facet_collector.rs
@@ -37,7 +37,10 @@ impl<'a> PartialOrd<Hit<'a>> for Hit<'a> {
 
 impl<'a> Ord for Hit<'a> {
     fn cmp(&self, other: &Self) -> Ordering {
-        other.count.cmp(&self.count)
+        match other.count.cmp(&self.count) {
+            Ordering::Equal => self.facet.cmp(other.facet),
+            x => x,
+        }
     }
 }
 

From 54decc60bb91077ad869eafa31bf3e6b1b22e655 Mon Sep 17 00:00:00 2001
From: Hardik Prajapati <hardikpnsp@gmail.com>
Date: Wed, 7 Apr 2021 23:59:04 +0530
Subject: [PATCH 3/4] Fixed formatting using cargo fmt

---
 src/collector/facet_collector.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/collector/facet_collector.rs b/src/collector/facet_collector.rs
index 108a5d1f3..9e53d54ce 100644
--- a/src/collector/facet_collector.rs
+++ b/src/collector/facet_collector.rs
@@ -692,10 +692,7 @@ mod tests {
             let facets: Vec<(&Facet, u64)> = counts.top_k("/facet", 2);
             assert_eq!(
                 facets,
-                vec![
-                    (&Facet::from("/facet/c"), 4),
-                    (&Facet::from("/facet/a"), 2),
-                ]
+                vec![(&Facet::from("/facet/c"), 4), (&Facet::from("/facet/a"), 2)]
             );
         }
     }

From 71309c552802b180d6a61274f1fd27de5dfc266a Mon Sep 17 00:00:00 2001
From: Hardik Prajapati <hardikpnsp@gmail.com>
Date: Thu, 8 Apr 2021 01:05:34 +0530
Subject: [PATCH 4/4] Simplified chain orderings

---
 src/collector/facet_collector.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/collector/facet_collector.rs b/src/collector/facet_collector.rs
index 9e53d54ce..db5618442 100644
--- a/src/collector/facet_collector.rs
+++ b/src/collector/facet_collector.rs
@@ -37,10 +37,10 @@ impl<'a> PartialOrd<Hit<'a>> for Hit<'a> {
 
 impl<'a> Ord for Hit<'a> {
     fn cmp(&self, other: &Self) -> Ordering {
-        match other.count.cmp(&self.count) {
-            Ordering::Equal => self.facet.cmp(other.facet),
-            x => x,
-        }
+        other
+            .count
+            .cmp(&self.count)
+            .then(self.facet.cmp(other.facet))
     }
 }