fix(todo-continuation): improve stagnation detection accuracy

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

@@ -0,0 +1,105 @@
+/// <reference path="../../../bun-test.d.ts" />
+
+import { afterEach, beforeEach, describe, expect, it as test } from "bun:test"
+
+import { MAX_STAGNATION_COUNT } from "./constants"
+import { createSessionStateStore, type SessionStateStore } from "./session-state"
+
+describe("createSessionStateStore regressions", () => {
+  let sessionStateStore: SessionStateStore
+
+  beforeEach(() => {
+    sessionStateStore = createSessionStateStore()
+  })
+
+  afterEach(() => {
+    sessionStateStore.shutdown()
+  })
+
+  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", () => {
+        const sessionID = "ses-activity-progress"
+        const todos = [
+          { id: "1", content: "Task 1", status: "pending", priority: "high" },
+          { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+        ]
+        const state = sessionStateStore.getState(sessionID)
+
+        sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+        state.awaitingPostInjectionProgressCheck = true
+
+        const trackedState = sessionStateStore.getExistingState(sessionID)
+        if (!trackedState) {
+          throw new Error("Expected tracked session state")
+        }
+
+        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)
+      })
+    })
+  })
+
+  describe("#given todos only change order between idle checks", () => {
+    describe("#when the same todos are compared again", () => {
+      test("#then it keeps the snapshot stable and counts stagnation", () => {
+        const sessionID = "ses-stable-snapshot"
+        const firstTodos = [
+          { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+          { id: "1", content: "Task 1", status: "pending", priority: "high" },
+        ]
+        const reorderedTodos = [
+          { id: "1", content: "Task 1", status: "pending", priority: "high" },
+          { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+        ]
+        const state = sessionStateStore.getState(sessionID)
+
+        sessionStateStore.trackContinuationProgress(sessionID, 2, firstTodos)
+        state.awaitingPostInjectionProgressCheck = true
+
+        const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, 2, reorderedTodos)
+
+        expect(progressUpdate.hasProgressed).toBe(false)
+        expect(progressUpdate.progressSource).toBe("none")
+        expect(progressUpdate.stagnationCount).toBe(1)
+      })
+    })
+  })
+
+  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", () => {
+        const sessionID = "ses-stagnation-recovery"
+        const todos = [
+          { id: "1", content: "Task 1", status: "pending", priority: "high" },
+          { id: "2", content: "Task 2", status: "pending", priority: "medium" },
+        ]
+        const state = sessionStateStore.getState(sessionID)
+
+        sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+
+        for (let index = 0; index < MAX_STAGNATION_COUNT; index++) {
+          state.awaitingPostInjectionProgressCheck = true
+          sessionStateStore.trackContinuationProgress(sessionID, 2, todos)
+        }
+
+        const trackedState = sessionStateStore.getExistingState(sessionID)
+        if (!trackedState) {
+          throw new Error("Expected tracked session state")
+        }
+
+        trackedState.abortDetectedAt = undefined
+        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)
+      })
+    })
+  })
+})