From c5b7f4c8642c92f9d5f01a97f39af4c358982935 Mon Sep 17 00:00:00 2001
From: teernisse <teernisse@visiostack.com>
Date: Wed, 18 Feb 2026 12:39:57 -0500
Subject: [PATCH] (no description set)

---
 src/search/vector.rs | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/search/vector.rs b/src/search/vector.rs
index 1d307fe..5fc0633 100644
--- a/src/search/vector.rs
+++ b/src/search/vector.rs
@@ -136,6 +136,7 @@ mod tests {
 
     #[test]
     fn test_knn_k_never_exceeds_sqlite_vec_limit() {
+        // Brute-force: no combination of valid inputs should exceed 4096.
         for limit in [1, 10, 50, 100, 500, 1000, 1500, 2000, 5000] {
             for max_chunks in [1, 2, 5, 10, 50, 100, 200, 500, 1000] {
                 let k = compute_knn_k(limit, max_chunks);
@@ -149,33 +150,37 @@ mod tests {
 
     #[test]
     fn test_knn_k_reproduces_original_bug_scenario() {
+        // The original bug: limit=1500 (RECALL_CAP) with multiplier >= 8
+        // produced k=10_000 which exceeded sqlite-vec's 4096 cap.
         let k = compute_knn_k(1500, 1);
-        assert!(
-            k <= SQLITE_VEC_KNN_MAX,
-            "k={k} exceeded 4096 at RECALL_CAP with 1 chunk"
-        );
+        assert!(k <= SQLITE_VEC_KNN_MAX, "k={k} exceeded 4096 at RECALL_CAP with 1 chunk");
     }
 
     #[test]
     fn test_knn_k_small_limit_uses_minimum_multiplier() {
+        // With 1 chunk, multiplier clamps to minimum of 8.
         let k = compute_knn_k(10, 1);
         assert_eq!(k, 80);
     }
 
     #[test]
     fn test_knn_k_high_chunks_caps_multiplier() {
+        // With 200 chunks, multiplier = (200*3/2 + 1) = 301 → clamped to 200.
+        // limit=10 * 200 = 2000 < 4096.
         let k = compute_knn_k(10, 200);
         assert_eq!(k, 2000);
     }
 
     #[test]
     fn test_knn_k_zero_max_chunks_treated_as_one() {
+        // max_chunks_per_doc=0 → unsigned_abs().max(1) = 1
         let k = compute_knn_k(10, 0);
-        assert_eq!(k, 80);
+        assert_eq!(k, 80); // multiplier clamp(8, 200) → 8
     }
 
     #[test]
     fn test_knn_k_negative_max_chunks_uses_absolute() {
+        // Defensive: negative values use unsigned_abs
         let k = compute_knn_k(10, -5);
         assert_eq!(k, compute_knn_k(10, 5));
     }