diff --git a/mobile/src/session/mobile-native-chat-turn-disclosure-test-harness.ts b/mobile/src/session/mobile-native-chat-turn-disclosure-test-harness.ts
new file mode 100644
index 000000000000..ac1799d0b75d
--- /dev/null
+++ b/mobile/src/session/mobile-native-chat-turn-disclosure-test-harness.ts
@@ -0,0 +1,40 @@
+import { createElement } from 'react'
+import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
+import type { NativeChatTurnJournal } from '../../../src/shared/native-chat-turn-membership'
+import type { NativeChatSettledTurns } from '../../../src/shared/native-chat-turn-status'
+import { useMobileNativeChatTurnDisclosure } from './use-mobile-native-chat-turn-disclosure'
+
+export function MobileNativeChatTurnDisclosureHarness({
+  messages,
+  enabled,
+  isWorking = true,
+  settledTurns,
+  turnJournal,
+  workingStartedAt,
+  thinking,
+  lineYields,
+  scopeKey = 'host\0worktree\0tab-a'
+}: {
+  messages: readonly NativeChatMessage[]
+  enabled: boolean
+  isWorking?: boolean
+  settledTurns?: NativeChatSettledTurns
+  turnJournal?: NativeChatTurnJournal
+  workingStartedAt?: number | null
+  thinking?: boolean
+  lineYields?: boolean
+  scopeKey?: string
+}): React.JSX.Element {
+  const disclosure = useMobileNativeChatTurnDisclosure({
+    messages,
+    enabled,
+    isWorking,
+    settledTurns,
+    turnJournal,
+    workingStartedAt,
+    thinking,
+    lineYields,
+    scopeKey
+  })
+  return createElement('result', { disclosure })
+}
diff --git a/mobile/src/session/use-mobile-native-chat-turn-disclosure.test.tsx b/mobile/src/session/use-mobile-native-chat-turn-disclosure.test.tsx
index 766190a6bf07..51a5a1b483b2 100644
--- a/mobile/src/session/use-mobile-native-chat-turn-disclosure.test.tsx
+++ b/mobile/src/session/use-mobile-native-chat-turn-disclosure.test.tsx
@@ -9,7 +9,7 @@ import type {
 import { agentJournalSubmissionKey } from '../../../src/shared/agent-session-journal-item-key'
 import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
 import type { NativeChatTurnJournal } from '../../../src/shared/native-chat-turn-membership'
-import type { NativeChatSettledTurns } from '../../../src/shared/native-chat-turn-status'
+import { MobileNativeChatTurnDisclosureHarness as Harness } from './mobile-native-chat-turn-disclosure-test-harness'
 import { useMobileNativeChatTurnDisclosure } from './use-mobile-native-chat-turn-disclosure'
 
 function userMessage(id: string): NativeChatMessage {
@@ -22,41 +22,6 @@ function userMessage(id: string): NativeChatMessage {
   }
 }
 
-function Harness({
-  messages,
-  enabled,
-  isWorking = true,
-  settledTurns,
-  turnJournal,
-  workingStartedAt,
-  thinking,
-  lineYields,
-  scopeKey = 'host\0worktree\0tab-a'
-}: {
-  messages: readonly NativeChatMessage[]
-  enabled: boolean
-  isWorking?: boolean
-  settledTurns?: NativeChatSettledTurns
-  turnJournal?: NativeChatTurnJournal
-  workingStartedAt?: number | null
-  thinking?: boolean
-  lineYields?: boolean
-  scopeKey?: string
-}): React.JSX.Element {
-  const disclosure = useMobileNativeChatTurnDisclosure({
-    messages,
-    enabled,
-    isWorking,
-    settledTurns,
-    turnJournal,
-    workingStartedAt,
-    thinking,
-    lineYields,
-    scopeKey
-  })
-  return createElement('result', { disclosure })
-}
-
 describe('useMobileNativeChatTurnDisclosure', () => {
   let renderer: ReactTestRenderer | null = null
 
diff --git a/src/shared/structured-agent-session-live-turn.test.ts b/src/shared/structured-agent-session-live-turn.test.ts
index 5a4d1f7d43c8..389e6b2aff38 100644
--- a/src/shared/structured-agent-session-live-turn.test.ts
+++ b/src/shared/structured-agent-session-live-turn.test.ts
@@ -39,9 +39,13 @@ describe('isStructuredAgentSessionThinking', () => {
         state,
         ...(state === 'completed' ? { completedAt: 3 } : {})
       })
-    expect(isStructuredAgentSessionThinking([turnStart, withState('running')])).toBe(true)
+    expect(isStructuredAgentSessionThinking({ items: [turnStart, withState('running')] })).toBe(
+      true
+    )
     // Ended reasoning stays the newest row while Claude streams a tool's input after it.
-    expect(isStructuredAgentSessionThinking([turnStart, withState('completed')])).toBe(false)
+    expect(isStructuredAgentSessionThinking({ items: [turnStart, withState('completed')] })).toBe(
+      false
+    )
   })
 
   it('is false once a tool call, a message or a diff lands after the reasoning', () => {