Merge pull request #2370 from code-yeongyu/fix/issue-2322

fix: stop stagnant todo continuation loops

src/hooks/todo-continuation-enforcer/constants.ts

@@ -18,5 +18,6 @@ export const COUNTDOWN_GRACE_PERIOD_MS = 500
 
 export const ABORT_WINDOW_MS = 3000
 export const CONTINUATION_COOLDOWN_MS = 5_000
+export const MAX_STAGNATION_COUNT = 3
 export const MAX_CONSECUTIVE_FAILURES = 5
 export const FAILURE_RESET_WINDOW_MS = 5 * 60 * 1000

src/hooks/todo-continuation-enforcer/continuation-injection.ts

@@ -164,6 +164,7 @@ ${todoList}`
     if (injectionState) {
       injectionState.inFlight = false
       injectionState.lastInjectedAt = Date.now()
+      injectionState.awaitingPostInjectionProgressCheck = true
       injectionState.consecutiveFailures = 0
     }
   } catch (error) {

src/hooks/todo-continuation-enforcer/idle-event.ts

@@ -16,6 +16,7 @@ import {
 } from "./constants"
 import { isLastAssistantMessageAborted } from "./abort-detection"
 import { hasUnansweredQuestion } from "./pending-question-detection"
+import { shouldStopForStagnation } from "./stagnation-detection"
 import { getIncompleteCount } from "./todo"
 import type { MessageInfo, ResolvedMessageInfo, Todo } from "./types"
 import type { SessionStateStore } from "./session-state"
@@ -93,12 +94,14 @@ export async function handleSessionIdle(args: {
   }
 
   if (!todos || todos.length === 0) {
+    sessionStateStore.resetContinuationProgress(sessionID)
     log(`[${HOOK_NAME}] No todos`, { sessionID })
     return
   }
 
   const incompleteCount = getIncompleteCount(todos)
   if (incompleteCount === 0) {
+    sessionStateStore.resetContinuationProgress(sessionID)
     log(`[${HOOK_NAME}] All todos complete`, { sessionID, total: todos.length })
     return
   }
@@ -183,6 +186,11 @@ export async function handleSessionIdle(args: {
     return
   }
 
+  const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, incompleteCount, todos)
+  if (shouldStopForStagnation({ sessionID, incompleteCount, progressUpdate })) {
+    return
+  }
+
   startCountdown({
     ctx,
     sessionID,

src/hooks/todo-continuation-enforcer/session-state.test.ts

@@ -0,0 +1,146 @@
+/// <reference path="../../../bun-test.d.ts" />
+
+import { afterEach, beforeEach, describe, expect, it as test } from "bun:test"
+
+import { createSessionStateStore, type SessionStateStore } from "./session-state"
+
+describe("createSessionStateStore", () => {
+  let sessionStateStore: SessionStateStore
+
+  beforeEach(() => {
+    sessionStateStore = createSessionStateStore()
+  })
+
+  afterEach(() => {
+    sessionStateStore.shutdown()
+  })
+
+  test("given repeated incomplete counts after a continuation, tracks stagnation", () => {
+    // given
+    const sessionID = "ses-stagnation"
+    const state = sessionStateStore.getState(sessionID)
+
+    // when
+    const firstUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+    state.awaitingPostInjectionProgressCheck = true
+    const secondUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+    state.awaitingPostInjectionProgressCheck = true
+    const thirdUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+
+    // then
+    expect(firstUpdate.stagnationCount).toBe(0)
+    expect(secondUpdate.stagnationCount).toBe(1)
+    expect(thirdUpdate.stagnationCount).toBe(2)
+  })
+
+  test("given injection did not succeed, repeated incomplete counts do not track stagnation", () => {
+    // given
+    const sessionID = "ses-failed-injection"
+    const state = sessionStateStore.getState(sessionID)
+    state.lastInjectedAt = Date.now()
+
+    // when
+    const firstUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+    const secondUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+    const thirdUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+
+    // then
+    expect(firstUpdate.stagnationCount).toBe(0)
+    expect(secondUpdate.stagnationCount).toBe(0)
+    expect(thirdUpdate.stagnationCount).toBe(0)
+  })
+
+  test("given incomplete count decreases, resets stagnation tracking", () => {
+    // given
+    const sessionID = "ses-progress-reset"
+    const state = sessionStateStore.getState(sessionID)
+    state.lastInjectedAt = Date.now()
+    sessionStateStore.trackContinuationProgress(sessionID, 3)
+    sessionStateStore.trackContinuationProgress(sessionID, 3)
+
+    // when
+    const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2)
+
+    // then
+    expect(progressUpdate.hasProgressed).toBe(true)
+    expect(progressUpdate.stagnationCount).toBe(0)
+    expect(sessionStateStore.getState(sessionID).lastIncompleteCount).toBe(2)
+  })
+
+  test("given one todo completes while another is added, resets stagnation even when incomplete count stays the same", () => {
+    // given
+    const sessionID = "ses-completion-with-addition"
+    const state = sessionStateStore.getState(sessionID)
+    state.lastInjectedAt = Date.now()
+    const initialTodos = [
+      { id: "1", content: "Task 1", status: "pending", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+    ]
+    const progressedTodos = [
+      { id: "1", content: "Task 1", status: "completed", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+      { id: "3", content: "Task 3", status: "pending", priority: "low" },
+    ]
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+
+    // when
+    const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, progressedTodos)
+
+    // then
+    expect(progressUpdate.hasProgressed).toBe(true)
+    expect(progressUpdate.stagnationCount).toBe(0)
+  })
+
+  test("given todo status changes without count changes, treats it as progress", () => {
+    // given
+    const sessionID = "ses-status-change-progress"
+    const state = sessionStateStore.getState(sessionID)
+    state.lastInjectedAt = Date.now()
+    const initialTodos = [
+      { id: "1", content: "Task 1", status: "pending", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+    ]
+    const progressedTodos = [
+      { id: "1", content: "Task 1", status: "in_progress", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+    ]
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+
+    // when
+    const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, progressedTodos)
+
+    // then
+    expect(progressUpdate.hasProgressed).toBe(true)
+    expect(progressUpdate.stagnationCount).toBe(0)
+  })
+
+  test("given progress resumes after stagnation, restarts the stagnation count from zero", () => {
+    // given
+    const sessionID = "ses-progress-restarts-stagnation"
+    const state = sessionStateStore.getState(sessionID)
+    state.lastInjectedAt = Date.now()
+    const initialTodos = [
+      { id: "1", content: "Task 1", status: "pending", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+    ]
+    const progressedTodos = [
+      { id: "1", content: "Task 1", status: "in_progress", priority: "high" },
+      { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+    ]
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+    state.awaitingPostInjectionProgressCheck = true
+    sessionStateStore.trackContinuationProgress(sessionID, 2, initialTodos)
+    state.awaitingPostInjectionProgressCheck = true
+    sessionStateStore.trackContinuationProgress(sessionID, 2, progressedTodos)
+
+    // when
+    state.awaitingPostInjectionProgressCheck = true
+    const stagnatedAgainUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, progressedTodos)
+
+    // then
+    expect(stagnatedAgainUpdate.hasProgressed).toBe(false)
+    expect(stagnatedAgainUpdate.stagnationCount).toBe(1)
+  })
+})

src/hooks/todo-continuation-enforcer/session-state.ts

@@ -1,4 +1,4 @@
-import type { SessionState } from "./types"
+import type { SessionState, Todo } from "./types"
 
 // TTL for idle session state entries (10 minutes)
 const SESSION_STATE_TTL_MS = 10 * 60 * 1000
@@ -8,17 +8,34 @@ const SESSION_STATE_PRUNE_INTERVAL_MS = 2 * 60 * 1000
 interface TrackedSessionState {
   state: SessionState
   lastAccessedAt: number
+  lastCompletedCount?: number
+  lastTodoStatusSignature?: string
+}
+
+export interface ContinuationProgressUpdate {
+  previousIncompleteCount?: number
+  stagnationCount: number
+  hasProgressed: boolean
 }
 
 export interface SessionStateStore {
   getState: (sessionID: string) => SessionState
   getExistingState: (sessionID: string) => SessionState | undefined
+  trackContinuationProgress: (sessionID: string, incompleteCount: number, todos?: Todo[]) => ContinuationProgressUpdate
+  resetContinuationProgress: (sessionID: string) => void
   cancelCountdown: (sessionID: string) => void
   cleanup: (sessionID: string) => void
   cancelAllCountdowns: () => void
   shutdown: () => void
 }
 
+function getTodoStatusSignature(todos: Todo[]): string {
+  return todos
+    .map((todo) => `${todo.id ?? `${todo.content}:${todo.priority}`}:${todo.status}`)
+    .sort()
+    .join("|")
+}
+
 export function createSessionStateStore(): SessionStateStore {
   const sessions = new Map<string, TrackedSessionState>()
 
@@ -38,18 +55,27 @@ export function createSessionStateStore(): SessionStateStore {
     pruneInterval.unref()
   }
 
-  function getState(sessionID: string): SessionState {
+  function getTrackedSession(sessionID: string): TrackedSessionState {
     const existing = sessions.get(sessionID)
     if (existing) {
       existing.lastAccessedAt = Date.now()
-      return existing.state
+      return existing
     }
 
     const state: SessionState = {
+      stagnationCount: 0,
       consecutiveFailures: 0,
     }
-    sessions.set(sessionID, { state, lastAccessedAt: Date.now() })
+    const trackedSession: TrackedSessionState = {
-    return state
+      state,
+      lastAccessedAt: Date.now(),
+    }
+    sessions.set(sessionID, trackedSession)
+    return trackedSession
+  }
+
+  function getState(sessionID: string): SessionState {
+    return getTrackedSession(sessionID).state
   }
 
   function getExistingState(sessionID: string): SessionState | undefined {
@@ -61,6 +87,85 @@ export function createSessionStateStore(): SessionStateStore {
     return undefined
   }
 
+  function trackContinuationProgress(
+    sessionID: string,
+    incompleteCount: number,
+    todos?: Todo[]
+  ): ContinuationProgressUpdate {
+    const trackedSession = getTrackedSession(sessionID)
+    const state = trackedSession.state
+    const previousIncompleteCount = state.lastIncompleteCount
+    const currentCompletedCount = todos?.filter((todo) => todo.status === "completed").length
+    const currentTodoStatusSignature = todos ? getTodoStatusSignature(todos) : undefined
+    const hasCompletedMoreTodos =
+      currentCompletedCount !== undefined
+      && trackedSession.lastCompletedCount !== undefined
+      && currentCompletedCount > trackedSession.lastCompletedCount
+    const hasTodoStatusChanged =
+      currentTodoStatusSignature !== undefined
+      && trackedSession.lastTodoStatusSignature !== undefined
+      && currentTodoStatusSignature !== trackedSession.lastTodoStatusSignature
+    const hadSuccessfulInjectionAwaitingProgressCheck = state.awaitingPostInjectionProgressCheck === true
+
+    state.lastIncompleteCount = incompleteCount
+    if (currentCompletedCount !== undefined) {
+      trackedSession.lastCompletedCount = currentCompletedCount
+    }
+    if (currentTodoStatusSignature !== undefined) {
+      trackedSession.lastTodoStatusSignature = currentTodoStatusSignature
+    }
+
+    if (previousIncompleteCount === undefined) {
+      state.stagnationCount = 0
+      return {
+        previousIncompleteCount,
+        stagnationCount: state.stagnationCount,
+        hasProgressed: false,
+      }
+    }
+
+    if (incompleteCount < previousIncompleteCount || hasCompletedMoreTodos || hasTodoStatusChanged) {
+      state.stagnationCount = 0
+      state.awaitingPostInjectionProgressCheck = false
+      return {
+        previousIncompleteCount,
+        stagnationCount: state.stagnationCount,
+        hasProgressed: true,
+      }
+    }
+
+    if (!hadSuccessfulInjectionAwaitingProgressCheck) {
+      return {
+        previousIncompleteCount,
+        stagnationCount: state.stagnationCount,
+        hasProgressed: false,
+      }
+    }
+
+    state.awaitingPostInjectionProgressCheck = false
+    state.stagnationCount += 1
+    return {
+      previousIncompleteCount,
+      stagnationCount: state.stagnationCount,
+      hasProgressed: false,
+    }
+  }
+
+  function resetContinuationProgress(sessionID: string): void {
+    const trackedSession = sessions.get(sessionID)
+    if (!trackedSession) return
+
+    trackedSession.lastAccessedAt = Date.now()
+
+    const { state } = trackedSession
+
+    state.lastIncompleteCount = undefined
+    state.stagnationCount = 0
+    state.awaitingPostInjectionProgressCheck = false
+    trackedSession.lastCompletedCount = undefined
+    trackedSession.lastTodoStatusSignature = undefined
+  }
+
   function cancelCountdown(sessionID: string): void {
     const tracked = sessions.get(sessionID)
     if (!tracked) return
@@ -100,6 +205,8 @@ export function createSessionStateStore(): SessionStateStore {
   return {
     getState,
     getExistingState,
+    trackContinuationProgress,
+    resetContinuationProgress,
     cancelCountdown,
     cleanup,
     cancelAllCountdowns,

src/hooks/todo-continuation-enforcer/stagnation-detection.ts

@@ -0,0 +1,33 @@
+import { log } from "../../shared/logger"
+
+import { HOOK_NAME, MAX_STAGNATION_COUNT } from "./constants"
+import type { ContinuationProgressUpdate } from "./session-state"
+
+export function shouldStopForStagnation(args: {
+  sessionID: string
+  incompleteCount: number
+  progressUpdate: ContinuationProgressUpdate
+}): boolean {
+  const { sessionID, incompleteCount, progressUpdate } = args
+
+  if (progressUpdate.hasProgressed) {
+    log(`[${HOOK_NAME}] Progress detected: reset stagnation count`, {
+      sessionID,
+      previousIncompleteCount: progressUpdate.previousIncompleteCount,
+      incompleteCount,
+    })
+  }
+
+  if (progressUpdate.stagnationCount < MAX_STAGNATION_COUNT) {
+    return false
+  }
+
+  log(`[${HOOK_NAME}] Skipped: todo continuation stagnated`, {
+    sessionID,
+    incompleteCount,
+    previousIncompleteCount: progressUpdate.previousIncompleteCount,
+    stagnationCount: progressUpdate.stagnationCount,
+    maxStagnationCount: MAX_STAGNATION_COUNT,
+  })
+  return true
+}

src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts

@@ -8,6 +8,7 @@ import {
   CONTINUATION_COOLDOWN_MS,
   FAILURE_RESET_WINDOW_MS,
   MAX_CONSECUTIVE_FAILURES,
+  MAX_STAGNATION_COUNT,
 } from "./constants"
 
 type TimerCallback = (...args: any[]) => void
@@ -626,6 +627,57 @@ describe("todo-continuation-enforcer", () => {
     const sessionID = "main-max-consecutive-failures"
     setMainSession(sessionID)
     const mockInput = createMockPluginInput()
+    const incompleteCounts = [5, 4, 5, 4, 5, 4]
+    let todoCallCount = 0
+    mockInput.client.session.todo = async () => {
+      const countIndex = Math.min(Math.floor(todoCallCount / 2), incompleteCounts.length - 1)
+      const incompleteCount = incompleteCounts[countIndex] ?? incompleteCounts[incompleteCounts.length - 1] ?? 1
+      todoCallCount += 1
+      return {
+        data: Array.from({ length: incompleteCount }, (_, index) => ({
+          id: String(index + 1),
+          content: `Task ${index + 1}`,
+          status: "pending",
+          priority: "high",
+        })),
+      }
+    }
+    mockInput.client.session.promptAsync = async (opts: PromptRequestOptions) => {
+      promptCalls.push({
+        sessionID: opts.path.id,
+        agent: opts.body.agent,
+        model: opts.body.model,
+        text: opts.body.parts[0].text,
+      })
+      throw new Error("simulated auth failure")
+    }
+    const hook = createTodoContinuationEnforcer(mockInput, {})
+
+    //#when
+    for (let index = 0; index < MAX_CONSECUTIVE_FAILURES; index++) {
+      await hook.handler({ event: { type: "session.idle", properties: { sessionID } } })
+      await fakeTimers.advanceBy(2500, true)
+      if (index < MAX_CONSECUTIVE_FAILURES - 1) {
+        await fakeTimers.advanceClockBy(1_000_000)
+      }
+    }
+    await hook.handler({ event: { type: "session.idle", properties: { sessionID } } })
+    await fakeTimers.advanceBy(2500, true)
+
+    //#then
+    expect(promptCalls).toHaveLength(MAX_CONSECUTIVE_FAILURES)
+  }, { timeout: 30000 })
+
+  test("should not stop retries early for unchanged todos when injections keep failing", async () => {
+    //#given
+    const sessionID = "main-unchanged-todos-max-failures"
+    setMainSession(sessionID)
+    const mockInput = createMockPluginInput()
+    mockInput.client.session.todo = async () => ({
+      data: [
+        { id: "1", content: "Task 1", status: "pending", priority: "high" },
+      ],
+    })
     mockInput.client.session.promptAsync = async (opts: PromptRequestOptions) => {
       promptCalls.push({
         sessionID: opts.path.id,
@@ -657,6 +709,21 @@ describe("todo-continuation-enforcer", () => {
     const sessionID = "main-recovery-after-max-failures"
     setMainSession(sessionID)
     const mockInput = createMockPluginInput()
+    const incompleteCounts = [5, 4, 5, 4, 5, 4, 5]
+    let todoCallCount = 0
+    mockInput.client.session.todo = async () => {
+      const countIndex = Math.min(Math.floor(todoCallCount / 2), incompleteCounts.length - 1)
+      const incompleteCount = incompleteCounts[countIndex] ?? incompleteCounts[incompleteCounts.length - 1] ?? 1
+      todoCallCount += 1
+      return {
+        data: Array.from({ length: incompleteCount }, (_, index) => ({
+          id: String(index + 1),
+          content: `Task ${index + 1}`,
+          status: "pending",
+          priority: "high",
+        })),
+      }
+    }
     mockInput.client.session.promptAsync = async (opts: PromptRequestOptions) => {
       promptCalls.push({
         sessionID: opts.path.id,
@@ -753,7 +820,7 @@ describe("todo-continuation-enforcer", () => {
     expect(promptCalls).toHaveLength(3)
   }, { timeout: 30000 })
 
-  test("should keep injecting even when todos remain unchanged across cycles", async () => {
+  test("should stop injecting after max stagnation cycles when todos remain unchanged across cycles", async () => {
     //#given
     const sessionID = "main-no-stagnation-cap"
     setMainSession(sessionID)
@@ -784,8 +851,8 @@ describe("todo-continuation-enforcer", () => {
     await hook.handler({ event: { type: "session.idle", properties: { sessionID } } })
     await fakeTimers.advanceBy(2500, true)
 
-    //#then — all 5 injections should fire (no stagnation cap)
+    // then
-    expect(promptCalls).toHaveLength(5)
+    expect(promptCalls).toHaveLength(MAX_STAGNATION_COUNT)
   }, { timeout: 60000 })
 
   test("should skip idle handling while injection is in flight", async () => {

src/hooks/todo-continuation-enforcer/types.ts

@@ -27,8 +27,11 @@ export interface SessionState {
   isRecovering?: boolean
   countdownStartedAt?: number
   abortDetectedAt?: number
+  lastIncompleteCount?: number
   lastInjectedAt?: number
+  awaitingPostInjectionProgressCheck?: boolean
   inFlight?: boolean
+  stagnationCount: number
   consecutiveFailures: number
 }