From cadd00a428dac5eb4d618ae09412409d018bf2c0 Mon Sep 17 00:00:00 2001
From: Rick Zhou <rinick@gmail.com>
Date: Mon, 16 Nov 2020 00:51:36 -0800
Subject: [PATCH] fix: scroll position should be reset when all tabs are
 removed (#332)

* reset scroll when there is no active tab

* add test: scroll to 0 when activeKey is null
---
 src/TabNavList/index.tsx | 10 +++++++---
 tests/overflow.test.tsx  |  9 +++++++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/TabNavList/index.tsx b/src/TabNavList/index.tsx
index c7ccbcbb..b384420b 100644
--- a/src/TabNavList/index.tsx
+++ b/src/TabNavList/index.tsx
@@ -207,9 +207,13 @@ function TabNavList(props: TabNavListProps, ref: React.Ref<HTMLDivElement>) {
 
   // ========================= Scroll ========================
   function scrollToTab(key = activeKey) {
-    const tabOffset = tabOffsets.get(key);
-
-    if (!tabOffset) return;
+    const tabOffset = tabOffsets.get(key) || {
+      width: 0,
+      height: 0,
+      left: 0,
+      right: 0,
+      top: 0,
+    };
 
     if (tabPositionTopOrBottom) {
       // ============ Align with top & bottom ============
diff --git a/tests/overflow.test.tsx b/tests/overflow.test.tsx
index 9029b0fe..eeb5a649 100644
--- a/tests/overflow.test.tsx
+++ b/tests/overflow.test.tsx
@@ -276,6 +276,15 @@ describe('Tabs.Overflow', () => {
       expect(getTransformX(wrapper)).toEqual(-20);
       expect(onTabScroll).toHaveBeenCalledWith({ direction: 'left' });
 
+      // scroll to 0 when activeKey is null
+      onTabScroll.mockReset();
+      wrapper.setProps({ activeKey: null });
+      act(() => {
+        jest.runAllTimers();
+        wrapper.update();
+      });
+      expect(getTransformX(wrapper)).toEqual(0);
+
       jest.useRealTimers();
     });