Resolve mobile task agent selection before commit (#3261)

mobile/app/h/[hostId]/tasks.tsx

@@ -59,6 +59,7 @@ import {
   filterWorkspaceAgents,
   isWorkspaceAgentEnabled,
   pickWorkspaceAgent,
+  resolveWorkspaceAgentSelection,
   workspaceAgentLabel,
   type WorkspaceAgentChoice
 } from '../../../src/tasks/workspace-agent-selection'
@@ -4998,42 +4999,22 @@ export default function MobileTasksScreen() {
     workspaceCreateTargetRepo
   ])
 
-  useEffect(() => {
-    if (!tasksSupported || !workspaceCreateDraft || workspaceAgentOverridden) return
-    setWorkspaceAgent(pickWorkspaceAgent(runtimeTaskSettings, workspaceDetectedAgentIds))
-  }, [
-    runtimeTaskSettings,
-    tasksSupported,
-    workspaceAgentOverridden,
-    workspaceCreateDraft,
-    workspaceDetectedAgentIds
-  ])
-
-  useEffect(() => {
-    if (
-      !workspaceCreateDraft ||
-      !tasksSupported ||
-      workspaceDetectedAgentIds === null ||
-      !workspaceAgent ||
-      workspaceAgent === 'blank' ||
-      (workspaceDetectedAgentIds.has(workspaceAgent) &&
-        isWorkspaceAgentEnabled(workspaceAgent, runtimeTaskSettings.disabledTuiAgents))
-    ) {
-      return
-    }
-    // Why: the drawer can open before SSH/local detection settles. If the user
-    // picked an agent that is not actually available on that host, fall back to
-    // the same detected-agent rule desktop uses instead of launching a bad CLI.
-    setWorkspaceAgent(pickWorkspaceAgent(runtimeTaskSettings, workspaceDetectedAgentIds))
-    setWorkspaceAgentOverridden(false)
-  }, [
-    runtimeTaskSettings,
-    tasksSupported,
-    workspaceAgent,
-    workspaceCreateDraft,
-    workspaceDetectedAgentIds,
-    runtimeTaskSettings.disabledTuiAgents
-  ])
+  const workspaceAgentSelection = resolveWorkspaceAgentSelection({
+    selectionActive: tasksSupported && workspaceCreateDraft !== null,
+    settings: runtimeTaskSettings,
+    detectedAgentIds: workspaceDetectedAgentIds,
+    agent: workspaceAgent,
+    overridden: workspaceAgentOverridden
+  })
+  if (
+    workspaceAgentSelection.agent !== workspaceAgent ||
+    workspaceAgentSelection.overridden !== workspaceAgentOverridden
+  ) {
+    // Why: the drawer can open before SSH/local detection settles. Resolve the
+    // visible agent before commit so users do not see an unavailable override.
+    setWorkspaceAgent(workspaceAgentSelection.agent)
+    setWorkspaceAgentOverridden(workspaceAgentSelection.overridden)
+  }
 
   const resolvedWorkspaceAgent = useMemo(
     () => workspaceAgent ?? pickWorkspaceAgent(runtimeTaskSettings, workspaceDetectedAgentIds),

mobile/src/tasks/workspace-agent-selection.test.ts

@@ -3,6 +3,7 @@ import { describe, expect, it } from 'vitest'
 import {
   normalizeWorkspaceAgent,
   pickWorkspaceAgent,
+  resolveWorkspaceAgentSelection,
   workspaceAgentLabel
 } from './workspace-agent-selection'
 
@@ -54,4 +55,52 @@ describe('workspace agent selection', () => {
     expect(normalizeWorkspaceAgent('__blank__')).toBe('blank')
     expect(workspaceAgentLabel('codex')).toBe('Codex')
   })
+
+  it('keeps automatic selection current while create selection is active', () => {
+    expect(
+      resolveWorkspaceAgentSelection({
+        selectionActive: true,
+        settings: { defaultTuiAgent: 'codex' },
+        detectedAgentIds: new Set(['claude', 'codex']),
+        agent: null,
+        overridden: false
+      })
+    ).toEqual({ agent: 'codex', overridden: false })
+  })
+
+  it('preserves a valid user override', () => {
+    expect(
+      resolveWorkspaceAgentSelection({
+        selectionActive: true,
+        settings: { defaultTuiAgent: 'claude' },
+        detectedAgentIds: new Set(['claude', 'codex']),
+        agent: 'codex',
+        overridden: true
+      })
+    ).toEqual({ agent: 'codex', overridden: true })
+  })
+
+  it('falls back when a user override is unavailable after detection settles', () => {
+    expect(
+      resolveWorkspaceAgentSelection({
+        selectionActive: true,
+        settings: { defaultTuiAgent: 'codex' },
+        detectedAgentIds: new Set(['claude']),
+        agent: 'codex',
+        overridden: true
+      })
+    ).toEqual({ agent: 'claude', overridden: false })
+  })
+
+  it('does not repair inactive selection state', () => {
+    expect(
+      resolveWorkspaceAgentSelection({
+        selectionActive: false,
+        settings: { defaultTuiAgent: 'codex' },
+        detectedAgentIds: new Set(['codex']),
+        agent: null,
+        overridden: false
+      })
+    ).toEqual({ agent: null, overridden: false })
+  })
 })

mobile/src/tasks/workspace-agent-selection.ts

@@ -15,6 +15,17 @@ type WorkspaceAgentSettings = {
   disabledTuiAgents?: unknown
 }
 
+export type WorkspaceAgentSelectionState = {
+  agent: WorkspaceAgentChoice | null
+  overridden: boolean
+}
+
+type ResolveWorkspaceAgentSelectionArgs = WorkspaceAgentSelectionState & {
+  selectionActive: boolean
+  settings: WorkspaceAgentSettings
+  detectedAgentIds: Set<string> | null
+}
+
 export function workspaceAgentLabel(agent: WorkspaceAgentChoice): string {
   return agent === 'blank' ? 'Blank Terminal' : MOBILE_TUI_AGENT_LABELS[agent]
 }
@@ -55,3 +66,32 @@ export function filterWorkspaceAgents(agents: readonly TuiAgent[], disabled?: un
 export function isWorkspaceAgentEnabled(agent: TuiAgent, disabled?: unknown): boolean {
   return isMobileTuiAgentEnabled(agent, disabled)
 }
+
+export function resolveWorkspaceAgentSelection({
+  selectionActive,
+  settings,
+  detectedAgentIds,
+  agent,
+  overridden
+}: ResolveWorkspaceAgentSelectionArgs): WorkspaceAgentSelectionState {
+  const current = { agent, overridden }
+  if (!selectionActive) {
+    return current
+  }
+
+  const pickedAgent = pickWorkspaceAgent(settings, detectedAgentIds)
+  if (!overridden) {
+    return agent === pickedAgent ? current : { agent: pickedAgent, overridden: false }
+  }
+
+  if (
+    detectedAgentIds === null ||
+    !agent ||
+    agent === 'blank' ||
+    (detectedAgentIds.has(agent) && isWorkspaceAgentEnabled(agent, settings.disabledTuiAgents))
+  ) {
+    return current
+  }
+
+  return { agent: pickedAgent, overridden: false }
+}