From 19676b2703e18204e501037c8d9043cb3cbdcabf Mon Sep 17 00:00:00 2001
From: David <david.nissimoff@gmail.com>
Date: Sun, 27 Jun 2021 11:24:08 -0700
Subject: [PATCH] Fix #650: checkIndexBounds off by 1 validation

---
 packages/react-swipeable-views-core/src/checkIndexBounds.js   | 4 ++--
 .../react-swipeable-views-core/src/checkIndexBounds.test.js   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/react-swipeable-views-core/src/checkIndexBounds.js b/packages/react-swipeable-views-core/src/checkIndexBounds.js
index 9007ee87..efe5ed86 100644
--- a/packages/react-swipeable-views-core/src/checkIndexBounds.js
+++ b/packages/react-swipeable-views-core/src/checkIndexBounds.js
@@ -7,8 +7,8 @@ const checkIndexBounds = props => {
   const childrenCount = React.Children.count(children);
 
   warning(
-    index >= 0 && index <= childrenCount,
-    `react-swipeable-view: the new index: ${index} is out of bounds: [0-${childrenCount}].`,
+    index >= 0 && index < childrenCount,
+    `react-swipeable-view: the new index: ${index} is out of bounds: [0-${childrenCount - 1}].`,
   );
 };
 
diff --git a/packages/react-swipeable-views-core/src/checkIndexBounds.test.js b/packages/react-swipeable-views-core/src/checkIndexBounds.test.js
index 8be00318..bc37de63 100644
--- a/packages/react-swipeable-views-core/src/checkIndexBounds.test.js
+++ b/packages/react-swipeable-views-core/src/checkIndexBounds.test.js
@@ -28,13 +28,13 @@ describe('checkIndexBounds', () => {
 
   it('should warn when the index is out of bounds', () => {
     checkIndexBounds({
-      index: 3,
+      index: 2,
       children,
     });
     assert.strictEqual(consoleStub.callCount, 1);
     assert.strictEqual(
       consoleStub.args[0][0],
-      'Warning: react-swipeable-view: the new index: 3 is out of bounds: [0-2].',
+      'Warning: react-swipeable-view: the new index: 2 is out of bounds: [0-1].',
     );
   });
 });