diff --git a/packages/client/ui-primitives/tests/tooltip.spec.tsx b/packages/client/ui-primitives/tests/tooltip.spec.tsx
new file mode 100644
index 0000000000..c71124040d
--- /dev/null
+++ b/packages/client/ui-primitives/tests/tooltip.spec.tsx
@@ -0,0 +1,100 @@
+// @vitest-environment jsdom
+import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { Tooltip } from '@deepseek-ai/dsh-client-ui-primitives'
+
+afterEach(cleanup)
+
+describe('Tooltip', () => {
+  it('shows the bubble to the right on hover and hides it on leave', () => {
+    render(
+      <Tooltip label="Open sidebar">
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    const anchor = screen.getByText('anchor')
+    fireEvent.mouseEnter(anchor)
+    const bubble = screen.getByRole('tooltip')
+    expect(bubble.textContent).toBe('Open sidebar')
+    expect(bubble.getAttribute('data-side')).toBe('right')
+    // jsdom rects are all-zero: right placement lands at the +10 gutter.
+    expect(bubble.style.left).toBe('10px')
+    expect(bubble.style.top).toBe('0px')
+    fireEvent.mouseLeave(anchor)
+    expect(screen.queryByRole('tooltip')).toBeNull()
+  })
+
+  it('supports bottom placement and the focus/blur channel', () => {
+    render(
+      <Tooltip label="Below" side="bottom">
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    const anchor = screen.getByText('anchor')
+    fireEvent.focus(anchor)
+    const bubble = screen.getByRole('tooltip')
+    expect(bubble.getAttribute('data-side')).toBe('bottom')
+    expect(bubble.style.left).toBe('0px')
+    expect(bubble.style.top).toBe('8px')
+    fireEvent.blur(anchor)
+    expect(screen.queryByRole('tooltip')).toBeNull()
+  })
+
+  it('chains the anchor\'s own handlers ahead of the tooltip\'s', () => {
+    const onMouseEnter = vi.fn()
+    const onMouseLeave = vi.fn()
+    const onFocus = vi.fn()
+    const onBlur = vi.fn()
+    render(
+      <Tooltip label="Chained">
+        <button type="button" onMouseEnter={onMouseEnter} onMouseLeave={onMouseLeave} onFocus={onFocus} onBlur={onBlur}>anchor</button>
+      </Tooltip>,
+    )
+    const anchor = screen.getByText('anchor')
+    fireEvent.mouseEnter(anchor)
+    fireEvent.mouseLeave(anchor)
+    fireEvent.focus(anchor)
+    fireEvent.blur(anchor)
+    expect(onMouseEnter).toHaveBeenCalledOnce()
+    expect(onMouseLeave).toHaveBeenCalledOnce()
+    expect(onFocus).toHaveBeenCalledOnce()
+    expect(onBlur).toHaveBeenCalledOnce()
+  })
+
+  it('suppresses the bubble while disabled without remounting the anchor', () => {
+    const { rerender } = render(
+      <Tooltip label="Rail" disabled>
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    const anchor = screen.getByText('anchor')
+    fireEvent.mouseEnter(anchor)
+    expect(screen.queryByRole('tooltip')).toBeNull()
+    rerender(
+      <Tooltip label="Rail">
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    // Same DOM node: toggling disabled never remounted the anchor.
+    expect(screen.getByText('anchor')).toBe(anchor)
+    fireEvent.mouseEnter(anchor)
+    expect(screen.getByRole('tooltip')).toBeTruthy()
+  })
+
+  it('drops an already-visible bubble when disabled flips mid-hover', () => {
+    const { rerender } = render(
+      <Tooltip label="Rail">
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    fireEvent.mouseEnter(screen.getByText('anchor'))
+    expect(screen.getByRole('tooltip')).toBeTruthy()
+    // e.g. clicking a rail control expands the sidebar: no mouseleave fires.
+    rerender(
+      <Tooltip label="Rail" disabled>
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    expect(screen.queryByRole('tooltip')).toBeNull()
+  })
+})
diff --git a/packages/client/ui-sidebar/tests/sidebar-root.spec.tsx b/packages/client/ui-sidebar/tests/sidebar-root.spec.tsx
index d4d85bf3c0..e87d7fd4df 100644
--- a/packages/client/ui-sidebar/tests/sidebar-root.spec.tsx
+++ b/packages/client/ui-sidebar/tests/sidebar-root.spec.tsx
@@ -197,6 +197,9 @@ describe('SidebarRoot', () => {
     vi.useFakeTimers()
     try {
       const { onToggleSidebar } = mount(...projectData())
+      // While expanded the search control is inert (the row click focuses instead).
+      act(() => { fireEvent.click(screen.getByLabelText('Search sessions')) })
+      expect(onToggleSidebar).not.toHaveBeenCalled()
       act(() => { fireEvent.click(screen.getByLabelText('Collapse sidebar')) })
       act(() => { vi.advanceTimersByTime(300) })
       act(() => { fireEvent.click(screen.getByLabelText('Search sessions')) })