From 532307b98003367c75ee51a0fa0ab2c5b235b95a Mon Sep 17 00:00:00 2001
From: Marco Moretti <marco.moretti@ictandmore.it>
Date: Tue, 21 Apr 2020 21:46:01 +0200
Subject: [PATCH] [useScrollTrigger] Add test to fix useScrollTrigger when the
 page first load

---
 .../src/useScrollTrigger/useScrollTrigger.test.js     | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packages/material-ui/src/useScrollTrigger/useScrollTrigger.test.js b/packages/material-ui/src/useScrollTrigger/useScrollTrigger.test.js
index e9d5ec1081b09a..02237ce1780424 100644
--- a/packages/material-ui/src/useScrollTrigger/useScrollTrigger.test.js
+++ b/packages/material-ui/src/useScrollTrigger/useScrollTrigger.test.js
@@ -259,5 +259,16 @@ describe('useScrollTrigger', () => {
         assert.strictEqual(text(), test.result, `Index: ${index} ${JSON.stringify(test)}`);
       });
     });
+
+    it('should correctly evaluate scroll events on page first load', () => {
+      [
+        { offset: 101, result: 'true' },
+        { offset: 100, result: 'false' },
+      ].forEach((test, index) => {
+        window.pageYOffset = test.offset;
+        mount(<Test threshold={100} />);
+        assert.strictEqual(text(), test.result, `Index: ${index} ${JSON.stringify(test)}`);
+      });
+    });
   });
 });