From bf7d25be40d2a6551a7741a710fb99da743dd3e1 Mon Sep 17 00:00:00 2001
From: Welly Shen <hivoid19@gmail.com>
Date: Sat, 29 May 2021 00:05:51 +0800
Subject: [PATCH] fix: correct the high of bindary-search for finding the item
 index from scroll

---
 .changeset/orange-dolls-raise.md | 5 +++++
 src/useVirtual.ts                | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/orange-dolls-raise.md

diff --git a/.changeset/orange-dolls-raise.md b/.changeset/orange-dolls-raise.md
new file mode 100644
index 00000000..6b92f09e
--- /dev/null
+++ b/.changeset/orange-dolls-raise.md
@@ -0,0 +1,5 @@
+---
+"react-cool-virtual": patch
+---
+
+fix: correct the high of bindary-search for finding the item index from scroll
diff --git a/src/useVirtual.ts b/src/useVirtual.ts
index 202b08cc..4c309c49 100644
--- a/src/useVirtual.ts
+++ b/src/useVirtual.ts
@@ -147,7 +147,7 @@ export default <
       } else {
         vStart = findNearestBinarySearch(
           0,
-          msData.length,
+          msData.length - 1,
           scrollOffset,
           (idx) => msData[idx].start
         );