From 22a2f916b5f2f0e13a6d487fb639f9eb35afcc75 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 May 2026 12:52:40 +0000
Subject: [PATCH 1/3] Initial plan


From f0cac602e1cb511d08759cb4f122d8bfb03d25fd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 May 2026 12:57:50 +0000
Subject: [PATCH 2/3] fix: avoid bottom overscroll jitter during stream updates

---
 src/renderer/src/pages/ChatPage.vue       |  2 +-
 test/renderer/components/ChatPage.test.ts | 44 +++++++++++++++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/renderer/src/pages/ChatPage.vue b/src/renderer/src/pages/ChatPage.vue
index 5f358a60d..6eef85da4 100644
--- a/src/renderer/src/pages/ChatPage.vue
+++ b/src/renderer/src/pages/ChatPage.vue
@@ -384,7 +384,7 @@ function scrollToBottom(force = false) {
     const nextScrollHeight = el.scrollHeight
 
     if (shouldForce || nextScrollHeight > lastObservedScrollHeight) {
-      el.scrollTop = nextScrollHeight
+      el.scrollTop = Math.max(nextScrollHeight - el.clientHeight, 0)
     }
 
     syncScrollPosition()
diff --git a/test/renderer/components/ChatPage.test.ts b/test/renderer/components/ChatPage.test.ts
index fc4e70a1e..a953b8f4b 100644
--- a/test/renderer/components/ChatPage.test.ts
+++ b/test/renderer/components/ChatPage.test.ts
@@ -931,6 +931,50 @@ describe('ChatPage', () => {
     expect(chatClient.steerActiveTurn).not.toHaveBeenCalled()
   })
 
+  it('scrolls to bottom using max scrollTop during stream updates near bottom', async () => {
+    const rafSpy = vi.spyOn(window, 'requestAnimationFrame').mockImplementation((cb) => {
+      cb(0)
+      return 1
+    })
+    const cancelRafSpy = vi.spyOn(window, 'cancelAnimationFrame').mockImplementation(() => {})
+
+    try {
+      const { wrapper, messageStore } = await setup()
+      const chatPage = wrapper.get('[data-testid="chat-page"]').element as HTMLDivElement
+
+      let scrollHeight = 1200
+      let scrollTop = 0
+      Object.defineProperty(chatPage, 'clientHeight', {
+        configurable: true,
+        get: () => 500
+      })
+      Object.defineProperty(chatPage, 'scrollHeight', {
+        configurable: true,
+        get: () => scrollHeight
+      })
+      Object.defineProperty(chatPage, 'scrollTop', {
+        configurable: true,
+        get: () => scrollTop,
+        set: (value: number) => {
+          scrollTop = value
+        }
+      })
+
+      scrollTop = 700
+      await wrapper.get('[data-testid="chat-page"]').trigger('scroll')
+      await flushPromises()
+
+      scrollHeight = 1250
+      messageStore.streamRevision += 1
+      await flushPromises()
+
+      expect(scrollTop).toBe(750)
+    } finally {
+      rafSpy.mockRestore()
+      cancelRafSpy.mockRestore()
+    }
+  })
+
   it('opens the inline search with Ctrl+F and closes it with Escape', async () => {
     const { wrapper } = await setup()
 

From 8bf5cd6fc72e59ee40a4fe0a57921aa520fdd71e Mon Sep 17 00:00:00 2001
From: zerob13 <zerob13@gmail.com>
Date: Fri, 29 May 2026 10:13:08 +0800
Subject: [PATCH 3/3] test(chat): fix scroll raf mock

---
 test/renderer/components/ChatPage.test.ts | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/test/renderer/components/ChatPage.test.ts b/test/renderer/components/ChatPage.test.ts
index a953b8f4b..3671c3d91 100644
--- a/test/renderer/components/ChatPage.test.ts
+++ b/test/renderer/components/ChatPage.test.ts
@@ -932,11 +932,23 @@ describe('ChatPage', () => {
   })
 
   it('scrolls to bottom using max scrollTop during stream updates near bottom', async () => {
+    let nextFrameId = 1
+    const rafCallbacks = new Map<number, FrameRequestCallback>()
+    const flushRaf = async () => {
+      const callbacks = Array.from(rafCallbacks.values())
+      rafCallbacks.clear()
+      callbacks.forEach((cb) => cb(0))
+      await flushPromises()
+    }
     const rafSpy = vi.spyOn(window, 'requestAnimationFrame').mockImplementation((cb) => {
-      cb(0)
-      return 1
+      const frameId = nextFrameId
+      nextFrameId += 1
+      rafCallbacks.set(frameId, cb)
+      return frameId
+    })
+    const cancelRafSpy = vi.spyOn(window, 'cancelAnimationFrame').mockImplementation((frameId) => {
+      rafCallbacks.delete(frameId)
     })
-    const cancelRafSpy = vi.spyOn(window, 'cancelAnimationFrame').mockImplementation(() => {})
 
     try {
       const { wrapper, messageStore } = await setup()
@@ -960,13 +972,17 @@ describe('ChatPage', () => {
         }
       })
 
+      await flushRaf()
+
       scrollTop = 700
       await wrapper.get('[data-testid="chat-page"]').trigger('scroll')
       await flushPromises()
+      await flushRaf()
 
       scrollHeight = 1250
       messageStore.streamRevision += 1
       await flushPromises()
+      await flushRaf()
 
       expect(scrollTop).toBe(750)
     } finally {