fix: pr-bug-scan validated finding from #2972

Fix Settings > Agents availability updates so rapid queued writes preserve all requested disabled agents and repeated requests remain idempotent.

src/renderer/src/components/settings/AgentsPane.test.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable max-lines -- Why: Agents pane settings interactions share
+   store-backed queue fixtures that are easier to audit beside the UI helper coverage. */
 import React from 'react'
 import { renderToStaticMarkup } from 'react-dom/server'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
@@ -12,7 +14,8 @@ import {
   AgentStatusHooksSetting,
   AgentsPane,
   AGENTS_PANE_SEARCH_ENTRIES,
-  buildAgentEnabledSettingsUpdate
+  buildAgentAvailabilitySettingsUpdate,
+  createAgentAvailabilityUpdateQueue
 } from './AgentsPane'
 import { matchesSettingsSearch } from './settings-search'
 
@@ -35,6 +38,24 @@ type ReactElementLike = {
   props: Record<string, unknown>
 }
 
+type Deferred = {
+  promise: Promise<void>
+  resolve: () => void
+}
+
+function createDeferred(): Deferred {
+  let resolve!: () => void
+  const promise = new Promise<void>((next) => {
+    resolve = next
+  })
+  return { promise, resolve }
+}
+
+async function flushPromiseQueue(): Promise<void> {
+  await Promise.resolve()
+  await Promise.resolve()
+}
+
 function renderPane(
   settings: GlobalSettings,
   props: Partial<React.ComponentProps<typeof AgentsPane>> = {}
@@ -212,11 +233,11 @@ describe('AgentsPane', () => {
   })
 
   it('only toggles agent availability when the segmented value changes', () => {
-    const onToggleEnabled = vi.fn()
+    const onSetEnabled = vi.fn()
     const control = AgentAvailabilityControl({
       label: 'Claude',
       isEnabled: true,
-      onToggleEnabled
+      onSetEnabled
     })
     const props = control.props as {
       value: 'enabled' | 'disabled'
@@ -228,20 +249,21 @@ describe('AgentsPane', () => {
     expect(props.ariaLabel).toBe('Claude availability')
 
     props.onChange('enabled')
-    expect(onToggleEnabled).not.toHaveBeenCalled()
+    expect(onSetEnabled).not.toHaveBeenCalled()
 
     props.onChange('disabled')
-    expect(onToggleEnabled).toHaveBeenCalledTimes(1)
+    expect(onSetEnabled).toHaveBeenCalledWith(false)
   })
 
   it('clears the default agent when disabling that agent', () => {
     expect(
-      buildAgentEnabledSettingsUpdate(
+      buildAgentAvailabilitySettingsUpdate(
         {
           defaultTuiAgent: 'claude',
           disabledTuiAgents: []
         },
-        'claude'
+        'claude',
+        false
       )
     ).toEqual({
       disabledTuiAgents: ['claude'],
@@ -251,12 +273,13 @@ describe('AgentsPane', () => {
 
   it('keeps the default setting untouched when re-enabling an agent', () => {
     expect(
-      buildAgentEnabledSettingsUpdate(
+      buildAgentAvailabilitySettingsUpdate(
         {
           defaultTuiAgent: null,
           disabledTuiAgents: ['claude']
         },
-        'claude'
+        'claude',
+        true
       )
     ).toEqual({
       disabledTuiAgents: []
@@ -267,4 +290,109 @@ describe('AgentsPane', () => {
     expect(matchesSettingsSearch('wsl', AGENTS_PANE_SEARCH_ENTRIES)).toBe(true)
     expect(matchesSettingsSearch('windows', AGENTS_PANE_SEARCH_ENTRIES)).toBe(true)
   })
+
+  it('serializes rapid availability writes against the latest settings snapshot', async () => {
+    const queueAvailabilityUpdate = createAgentAvailabilityUpdateQueue()
+    const settings: GlobalSettings = {
+      ...getDefaultSettings('/tmp'),
+      defaultTuiAgent: null,
+      disabledTuiAgents: []
+    }
+    const writes: Deferred[] = []
+    const updates: Partial<GlobalSettings>[] = []
+
+    useAppStore.setState({ settings })
+    const updateSettings = vi.fn((update: Partial<GlobalSettings>) => {
+      updates.push(update)
+      const nextSettings = {
+        ...(useAppStore.getState().settings ?? settings),
+        ...update
+      }
+      const write = createDeferred()
+      writes.push(write)
+      return write.promise.then(() => {
+        useAppStore.setState({ settings: nextSettings })
+      })
+    })
+
+    const firstWrite = queueAvailabilityUpdate({
+      getSettings: () => useAppStore.getState().settings,
+      fallbackSettings: settings,
+      updateSettings,
+      agentId: 'claude',
+      enabled: false
+    })
+    const secondWrite = queueAvailabilityUpdate({
+      getSettings: () => useAppStore.getState().settings,
+      fallbackSettings: settings,
+      updateSettings,
+      agentId: 'codex',
+      enabled: false
+    })
+
+    await flushPromiseQueue()
+    expect(updateSettings).toHaveBeenCalledTimes(1)
+    expect(updates[0]).toMatchObject({ disabledTuiAgents: ['claude'] })
+
+    writes[0].resolve()
+    await firstWrite
+    await flushPromiseQueue()
+
+    expect(updateSettings).toHaveBeenCalledTimes(2)
+    expect(updates[1]).toMatchObject({ disabledTuiAgents: ['claude', 'codex'] })
+
+    writes[1].resolve()
+    await secondWrite
+  })
+
+  it('keeps repeated queued availability requests idempotent', async () => {
+    const queueAvailabilityUpdate = createAgentAvailabilityUpdateQueue()
+    const settings: GlobalSettings = {
+      ...getDefaultSettings('/tmp'),
+      defaultTuiAgent: null,
+      disabledTuiAgents: []
+    }
+    const writes: Deferred[] = []
+    const updates: Partial<GlobalSettings>[] = []
+
+    useAppStore.setState({ settings })
+    const updateSettings = vi.fn((update: Partial<GlobalSettings>) => {
+      updates.push(update)
+      const nextSettings = {
+        ...(useAppStore.getState().settings ?? settings),
+        ...update
+      }
+      const write = createDeferred()
+      writes.push(write)
+      return write.promise.then(() => {
+        useAppStore.setState({ settings: nextSettings })
+      })
+    })
+
+    const firstWrite = queueAvailabilityUpdate({
+      getSettings: () => useAppStore.getState().settings,
+      fallbackSettings: settings,
+      updateSettings,
+      agentId: 'claude',
+      enabled: false
+    })
+    const secondWrite = queueAvailabilityUpdate({
+      getSettings: () => useAppStore.getState().settings,
+      fallbackSettings: settings,
+      updateSettings,
+      agentId: 'claude',
+      enabled: false
+    })
+
+    await flushPromiseQueue()
+    writes[0].resolve()
+    await firstWrite
+    await flushPromiseQueue()
+
+    expect(updateSettings).toHaveBeenCalledTimes(2)
+    expect(updates[1]).toMatchObject({ disabledTuiAgents: ['claude'] })
+
+    writes[1].resolve()
+    await secondWrite
+  })
 })

src/renderer/src/components/settings/AgentsPane.tsx

@@ -34,6 +34,14 @@ type AgentsPaneProps = {
   wslCapabilitiesLoading?: boolean
 }
 
+type AgentAvailabilityUpdateQueueOptions = {
+  getSettings: () => GlobalSettings | null | undefined
+  fallbackSettings: GlobalSettings
+  updateSettings: AgentsPaneProps['updateSettings']
+  agentId: TuiAgent
+  enabled: boolean
+}
+
 type AgentRowProps = {
   agentId: TuiAgent
   label: string
@@ -44,7 +52,7 @@ type AgentRowProps = {
   isDefault: boolean
   cmdOverride: string | undefined
   onSetDefault: () => void
-  onToggleEnabled: () => void
+  onSetEnabled: (enabled: boolean) => void
   onSaveOverride: (value: string) => void
 }
 
@@ -59,29 +67,52 @@ type AgentAvailability = 'enabled' | 'disabled'
 type AgentAvailabilityControlProps = {
   label: string
   isEnabled: boolean
-  onToggleEnabled: () => void
+  onSetEnabled: (enabled: boolean) => void
 }
 
-export function buildAgentEnabledSettingsUpdate(
+export function buildAgentAvailabilitySettingsUpdate(
   settings: Pick<GlobalSettings, 'defaultTuiAgent' | 'disabledTuiAgents'>,
-  id: TuiAgent
+  id: TuiAgent,
+  enabled: boolean
 ): Pick<GlobalSettings, 'disabledTuiAgents'> & Partial<Pick<GlobalSettings, 'defaultTuiAgent'>> {
   const latestDisabled = normalizeDisabledTuiAgents(settings.disabledTuiAgents)
-  const wasDisabled = latestDisabled.includes(id)
-  const nextDisabled = wasDisabled
+  const nextDisabled = enabled
     ? latestDisabled.filter((agent) => agent !== id)
-    : [...latestDisabled, id]
+    : latestDisabled.includes(id)
+      ? latestDisabled
+      : [...latestDisabled, id]
 
   return {
     disabledTuiAgents: nextDisabled,
-    ...(settings.defaultTuiAgent === id && !wasDisabled ? { defaultTuiAgent: null } : {})
+    ...(settings.defaultTuiAgent === id && !enabled ? { defaultTuiAgent: null } : {})
   }
 }
 
+export function createAgentAvailabilityUpdateQueue(): (
+  options: AgentAvailabilityUpdateQueueOptions
+) => Promise<void> {
+  let pendingUpdate: Promise<unknown> = Promise.resolve()
+
+  return ({ getSettings, fallbackSettings, updateSettings, agentId, enabled }) => {
+    // Why: serialize full-array replacements so each write sees the store after
+    // the previous IPC has reconciled, while preserving the user's requested state.
+    pendingUpdate = pendingUpdate
+      .catch(() => {})
+      .then(() =>
+        updateSettings(
+          buildAgentAvailabilitySettingsUpdate(getSettings() ?? fallbackSettings, agentId, enabled)
+        )
+      )
+    return pendingUpdate.then(() => undefined)
+  }
+}
+
+const enqueueAgentAvailabilityUpdate = createAgentAvailabilityUpdateQueue()
+
 export function AgentAvailabilityControl({
   label,
   isEnabled,
-  onToggleEnabled
+  onSetEnabled
 }: AgentAvailabilityControlProps): React.JSX.Element {
   const value: AgentAvailability = isEnabled ? 'enabled' : 'disabled'
 
@@ -90,7 +121,7 @@ export function AgentAvailabilityControl({
       value={value}
       onChange={(next) => {
         if (next !== value) {
-          onToggleEnabled()
+          onSetEnabled(next === 'enabled')
         }
       }}
       ariaLabel={`${label} availability`}
@@ -170,7 +201,7 @@ function AgentRow({
   isDefault,
   cmdOverride,
   onSetDefault,
-  onToggleEnabled,
+  onSetEnabled,
   onSaveOverride
 }: AgentRowProps): React.JSX.Element {
   const [cmdOpen, setCmdOpen] = useState(Boolean(cmdOverride))
@@ -216,7 +247,7 @@ function AgentRow({
           <AgentAvailabilityControl
             label={label}
             isEnabled={isEnabled}
-            onToggleEnabled={onToggleEnabled}
+            onSetEnabled={onSetEnabled}
           />
 
           {isDetected && isEnabled && (
@@ -346,9 +377,14 @@ export function AgentsPane({
     updateSettings({ defaultTuiAgent: id })
   }
 
-  const toggleEnabled = (id: TuiAgent): void => {
-    const latestSettings = useAppStore.getState().settings ?? settings
-    updateSettings(buildAgentEnabledSettingsUpdate(latestSettings, id))
+  const setAgentEnabled = (id: TuiAgent, enabled: boolean): void => {
+    void enqueueAgentAvailabilityUpdate({
+      getSettings: () => useAppStore.getState().settings,
+      fallbackSettings: settings,
+      updateSettings,
+      agentId: id,
+      enabled
+    })
   }
 
   const saveOverride = (id: TuiAgent, value: string): void => {
@@ -474,7 +510,7 @@ export function AgentsPane({
                 isDefault={defaultAgent === agent.id}
                 cmdOverride={cmdOverrides[agent.id]}
                 onSetDefault={() => setDefault(agent.id)}
-                onToggleEnabled={() => toggleEnabled(agent.id)}
+                onSetEnabled={(enabled) => setAgentEnabled(agent.id, enabled)}
                 onSaveOverride={(v) => saveOverride(agent.id, v)}
               />
             ))}
@@ -506,7 +542,7 @@ export function AgentsPane({
                 isDefault={false}
                 cmdOverride={undefined}
                 onSetDefault={() => {}}
-                onToggleEnabled={() => toggleEnabled(agent.id)}
+                onSetEnabled={(enabled) => setAgentEnabled(agent.id, enabled)}
                 onSaveOverride={() => {}}
               />
             ))}