fix(todo-continuation): remove activity-based stagnation bypass

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

@@ -18,7 +18,7 @@ describe("createSessionStateStore regressions", () => {
 
   describe("#given external activity happens after a successful continuation", () => {
     describe("#when todos stay unchanged", () => {
-      test("#then it treats the activity as progress instead of stagnation", () => {
+      test("#then it keeps counting stagnation", () => {
         const sessionID = "ses-activity-progress"
         const todos = [
           { id: "1", content: "Task 1", status: "pending", priority: "high" },
@@ -37,9 +37,9 @@ describe("createSessionStateStore regressions", () => {
         trackedState.abortDetectedAt = undefined
         const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
 
-        expect(progressUpdate.hasProgressed).toBe(true)
-        expect(progressUpdate.progressSource).toBe("activity")
-        expect(progressUpdate.stagnationCount).toBe(0)
+        expect(progressUpdate.hasProgressed).toBe(false)
+        expect(progressUpdate.progressSource).toBe("none")
+        expect(progressUpdate.stagnationCount).toBe(1)
       })
     })
   })
@@ -72,7 +72,7 @@ describe("createSessionStateStore regressions", () => {
 
   describe("#given stagnation already halted a session", () => {
     describe("#when new activity appears before the next idle check", () => {
-      test("#then it resets the stop condition on the next progress check", () => {
+      test("#then it does not reset the stop condition", () => {
         const sessionID = "ses-stagnation-recovery"
         const todos = [
           { id: "1", content: "Task 1", status: "pending", priority: "high" },
@@ -96,9 +96,9 @@ describe("createSessionStateStore regressions", () => {
         const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
 
         expect(progressUpdate.previousStagnationCount).toBe(MAX_STAGNATION_COUNT)
-        expect(progressUpdate.hasProgressed).toBe(true)
-        expect(progressUpdate.progressSource).toBe("activity")
-        expect(progressUpdate.stagnationCount).toBe(0)
+        expect(progressUpdate.hasProgressed).toBe(false)
+        expect(progressUpdate.progressSource).toBe("none")
+        expect(progressUpdate.stagnationCount).toBe(MAX_STAGNATION_COUNT)
       })
     })
   })

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

@@ -16,8 +16,6 @@ interface TrackedSessionState {
   lastAccessedAt: number
   lastCompletedCount?: number
   lastTodoSnapshot?: string
-  activitySignalCount: number
-  lastObservedActivitySignalCount?: number
 }
 
 export interface ContinuationProgressUpdate {
@@ -25,7 +23,7 @@ export interface ContinuationProgressUpdate {
   previousStagnationCount: number
   stagnationCount: number
   hasProgressed: boolean
-  progressSource: "none" | "todo" | "activity"
+  progressSource: "none" | "todo"
 }
 
 export interface SessionStateStore {
@@ -98,17 +96,7 @@ export function createSessionStateStore(): SessionStateStore {
     const trackedSession: TrackedSessionState = {
       state: rawState,
       lastAccessedAt: Date.now(),
-      activitySignalCount: 0,
     }
-    trackedSession.state = new Proxy(rawState, {
-      set(target, property, value, receiver) {
-        if (property === "abortDetectedAt" && value === undefined) {
-          trackedSession.activitySignalCount += 1
-        }
-
-        return Reflect.set(target, property, value, receiver)
-      },
-    })
     sessions.set(sessionID, trackedSession)
     return trackedSession
   }
@@ -137,7 +125,6 @@ export function createSessionStateStore(): SessionStateStore {
     const previousStagnationCount = state.stagnationCount
     const currentCompletedCount = todos?.filter((todo) => todo.status === "completed").length
     const currentTodoSnapshot = todos ? getTodoSnapshot(todos) : undefined
-    const currentActivitySignalCount = trackedSession.activitySignalCount
     const hasCompletedMoreTodos =
       currentCompletedCount !== undefined
       && trackedSession.lastCompletedCount !== undefined
@@ -146,9 +133,6 @@ export function createSessionStateStore(): SessionStateStore {
       currentTodoSnapshot !== undefined
       && trackedSession.lastTodoSnapshot !== undefined
       && currentTodoSnapshot !== trackedSession.lastTodoSnapshot
-    const hasObservedExternalActivity =
-      trackedSession.lastObservedActivitySignalCount !== undefined
-      && currentActivitySignalCount > trackedSession.lastObservedActivitySignalCount
     const hadSuccessfulInjectionAwaitingProgressCheck = state.awaitingPostInjectionProgressCheck === true
 
     state.lastIncompleteCount = incompleteCount
@@ -158,7 +142,6 @@ export function createSessionStateStore(): SessionStateStore {
     if (currentTodoSnapshot !== undefined) {
       trackedSession.lastTodoSnapshot = currentTodoSnapshot
     }
-    trackedSession.lastObservedActivitySignalCount = currentActivitySignalCount
 
     if (previousIncompleteCount === undefined) {
       state.stagnationCount = 0
@@ -173,9 +156,7 @@ export function createSessionStateStore(): SessionStateStore {
 
     const progressSource = incompleteCount < previousIncompleteCount || hasCompletedMoreTodos || hasTodoSnapshotChanged
       ? "todo"
-      : hasObservedExternalActivity
-        ? "activity"
-        : "none"
+      : "none"
 
     if (progressSource !== "none") {
       state.stagnationCount = 0
@@ -223,8 +204,6 @@ export function createSessionStateStore(): SessionStateStore {
     state.awaitingPostInjectionProgressCheck = false
     trackedSession.lastCompletedCount = undefined
     trackedSession.lastTodoSnapshot = undefined
-    trackedSession.activitySignalCount = 0
-    trackedSession.lastObservedActivitySignalCount = undefined
   }
 
   function cancelCountdown(sessionID: string): void {

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

@@ -3,6 +3,8 @@
 import { describe, expect, it as test } from "bun:test"
 
 import { MAX_STAGNATION_COUNT } from "./constants"
+import { handleNonIdleEvent } from "./non-idle-events"
+import { createSessionStateStore } from "./session-state"
 import { shouldStopForStagnation } from "./stagnation-detection"
 
 describe("shouldStopForStagnation", () => {
@@ -25,7 +27,7 @@ describe("shouldStopForStagnation", () => {
       })
     })
 
-    describe("#when activity progress is detected after the halt", () => {
+    describe("#when todo progress is detected after the halt", () => {
       test("#then it clears the stop condition", () => {
         const shouldStop = shouldStopForStagnation({
           sessionID: "ses-recovered",
@@ -35,7 +37,7 @@ describe("shouldStopForStagnation", () => {
             previousStagnationCount: MAX_STAGNATION_COUNT,
             stagnationCount: 0,
             hasProgressed: true,
-            progressSource: "activity",
+            progressSource: "todo",
           },
         })
 
@@ -43,4 +45,60 @@ describe("shouldStopForStagnation", () => {
       })
     })
   })
+
+  describe("#given only non-idle tool and message events happen between idle checks", () => {
+    describe("#when todo state does not change across three idle cycles", () => {
+      test("#then stagnation count reaches three", () => {
+        // given
+        const sessionStateStore = createSessionStateStore()
+        const sessionID = "ses-non-idle-activity-without-progress"
+        const state = sessionStateStore.getState(sessionID)
+        const todos = [
+          { id: "1", content: "Task 1", status: "pending", priority: "high" },
+          { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+        ]
+
+        sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+
+        // when
+        state.awaitingPostInjectionProgressCheck = true
+        const firstCycle = sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+
+        handleNonIdleEvent({
+          eventType: "tool.execute.before",
+          properties: { sessionID },
+          sessionStateStore,
+        })
+        handleNonIdleEvent({
+          eventType: "message.updated",
+          properties: { info: { sessionID, role: "assistant" } },
+          sessionStateStore,
+        })
+
+        state.awaitingPostInjectionProgressCheck = true
+        const secondCycle = sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+
+        handleNonIdleEvent({
+          eventType: "tool.execute.after",
+          properties: { sessionID },
+          sessionStateStore,
+        })
+        handleNonIdleEvent({
+          eventType: "message.part.updated",
+          properties: { info: { sessionID, role: "assistant" } },
+          sessionStateStore,
+        })
+
+        state.awaitingPostInjectionProgressCheck = true
+        const thirdCycle = sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+
+        // then
+        expect(firstCycle.stagnationCount).toBe(1)
+        expect(secondCycle.stagnationCount).toBe(2)
+        expect(thirdCycle.stagnationCount).toBe(3)
+
+        sessionStateStore.shutdown()
+      })
+    })
+  })
 })