From 556cffa9f3ad62b3d78cc09506373c606421d47c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Chalifour?= <francois.chalifour@gmail.com>
Date: Tue, 25 May 2021 20:43:41 +0200
Subject: [PATCH] fix(js): support panel scroll top position in all browsers

Some browsers have specificities to retrieve the document scroll position.

See https://stackoverflow.com/a/28633515/9940315
---
 .../autocomplete-js/src/getPanelPlacementStyle.ts    | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/packages/autocomplete-js/src/getPanelPlacementStyle.ts b/packages/autocomplete-js/src/getPanelPlacementStyle.ts
index 4d59eb21e..bd62e71a2 100644
--- a/packages/autocomplete-js/src/getPanelPlacementStyle.ts
+++ b/packages/autocomplete-js/src/getPanelPlacementStyle.ts
@@ -15,10 +15,14 @@ export function getPanelPlacementStyle({
   environment,
 }: GetPanelPlacementStyleParams) {
   const containerRect = container.getBoundingClientRect();
-  const top =
-    environment.document.body.scrollTop +
-    containerRect.top +
-    containerRect.height;
+  // Some browsers have specificities to retrieve the document scroll position.
+  // See https://stackoverflow.com/a/28633515/9940315
+  const scrollTop =
+    (environment.pageYOffset as number) ||
+    environment.document.documentElement.scrollTop ||
+    environment.document.body.scrollTop ||
+    0;
+  const top = scrollTop + containerRect.top + containerRect.height;
 
   switch (panelPlacement) {
     case 'start': {