fix: harden delegation lifecycle against race conditions with per-task metadata, mutual-exclusion guards, and multi-layer failure recovery

packages/types/src/task.ts

@@ -93,8 +93,6 @@ export interface CreateTaskOptions {
 	consecutiveMistakeLimit?: number
 	experiments?: Record<string, boolean>
 	initialTodos?: TodoItem[]
-	/** Initial status for the task's history item (e.g., "active" for child tasks) */
-	initialStatus?: "active" | "delegated" | "completed"
 	/** Whether to start the task loop immediately (default: true).
 	 *  When false, the caller must invoke `task.start()` manually. */
 	startTask?: boolean

src/__tests__/history-resume-delegation.spec.ts

@@ -38,6 +38,10 @@ vi.mock("../core/task-persistence", async (importOriginal) => {
 		saveTaskMessages: vi.fn().mockResolvedValue(undefined),
 	}
 })
+vi.mock("../core/task-persistence/delegationMeta", () => ({
+	readDelegationMeta: vi.fn().mockResolvedValue(null),
+	saveDelegationMeta: vi.fn().mockResolvedValue(undefined),
+}))
 
 import { ClineProvider } from "../core/webview/ClineProvider"
 import { readTaskMessages } from "../core/task-persistence/taskMessages"
@@ -149,6 +153,7 @@ describe("History resume delegation - parent metadata transitions", () => {
 				overwriteApiConversationHistory: vi.fn().mockResolvedValue(undefined),
 			}),
 			updateTaskHistory: vi.fn().mockResolvedValue([]),
+			log: vi.fn(),
 		} as unknown as ClineProvider
 
 		// Start with existing messages in history
@@ -232,6 +237,7 @@ describe("History resume delegation - parent metadata transitions", () => {
 				overwriteApiConversationHistory: vi.fn().mockResolvedValue(undefined),
 			}),
 			updateTaskHistory: vi.fn().mockResolvedValue([]),
+			log: vi.fn(),
 		} as unknown as ClineProvider
 
 		// Include an assistant message with new_task tool_use to exercise the tool_result path
@@ -320,6 +326,7 @@ describe("History resume delegation - parent metadata transitions", () => {
 				overwriteApiConversationHistory: vi.fn().mockResolvedValue(undefined),
 			}),
 			updateTaskHistory: vi.fn().mockResolvedValue([]),
+			log: vi.fn(),
 		} as unknown as ClineProvider
 
 		// No assistant tool_use in history
@@ -555,6 +562,7 @@ describe("History resume delegation - parent metadata transitions", () => {
 				overwriteApiConversationHistory: vi.fn().mockResolvedValue(undefined),
 			}),
 			updateTaskHistory: vi.fn().mockResolvedValue([]),
+			log: vi.fn(),
 		} as unknown as ClineProvider
 
 		vi.mocked(readTaskMessages).mockResolvedValue([])
@@ -754,6 +762,7 @@ describe("History resume delegation - parent metadata transitions", () => {
 				overwriteApiConversationHistory: vi.fn().mockResolvedValue(undefined),
 			}),
 			updateTaskHistory: vi.fn().mockResolvedValue([]),
+			log: vi.fn(),
 		} as unknown as ClineProvider
 
 		// Mock read failures or empty returns

src/__tests__/provider-delegation.spec.ts

@@ -2,14 +2,20 @@
 
 import { describe, it, expect, vi } from "vitest"
 import { RooCodeEventName } from "@roo-code/types"
+
+vi.mock("../core/task-persistence/delegationMeta", () => ({
+	readDelegationMeta: vi.fn().mockResolvedValue(null),
+	saveDelegationMeta: vi.fn().mockResolvedValue(undefined),
+}))
+
 import { ClineProvider } from "../core/webview/ClineProvider"
 
 describe("ClineProvider.delegateParentAndOpenChild()", () => {
 	it("persists parent delegation metadata and emits TaskDelegated", async () => {
 		const providerEmit = vi.fn()
 		const parentTask = { taskId: "parent-1", emit: vi.fn() } as any
 
-		const childStart = vi.fn()
+		const childStart = vi.fn().mockResolvedValue(undefined)
 		const updateTaskHistory = vi.fn()
 		const removeClineFromStack = vi.fn().mockResolvedValue(undefined)
 		const createTask = vi.fn().mockResolvedValue({ taskId: "child-1", start: childStart })
@@ -48,6 +54,7 @@ describe("ClineProvider.delegateParentAndOpenChild()", () => {
 			updateTaskHistory,
 			handleModeSwitch,
 			log: vi.fn(),
+			contextProxy: { globalStorageUri: { fsPath: "/tmp" } },
 		} as unknown as ClineProvider
 
 		const params = {
@@ -63,18 +70,26 @@ describe("ClineProvider.delegateParentAndOpenChild()", () => {
 
 		// Invariant: parent closed before child creation
 		expect(removeClineFromStack).toHaveBeenCalledTimes(1)
-		// Child task is created with startTask: false and initialStatus: "active"
+		// Child task is created with startTask: false
 		expect(createTask).toHaveBeenCalledWith("Do something", undefined, parentTask, {
 			initialTodos: [],
-			initialStatus: "active",
 			startTask: false,
 		})
 
-		// Metadata persistence - parent gets "delegated" status (child status is set at creation via initialStatus)
-		expect(updateTaskHistory).toHaveBeenCalledTimes(1)
+		// Metadata persistence - child gets "active" status, parent gets "delegated" status
+		expect(updateTaskHistory).toHaveBeenCalledTimes(2)
 
-		// Parent set to "delegated"
-		const parentSaved = updateTaskHistory.mock.calls[0][0]
+		// Child set to "active" (first call)
+		const childSaved = updateTaskHistory.mock.calls[0][0]
+		expect(childSaved).toEqual(
+			expect.objectContaining({
+				id: "child-1",
+				status: "active",
+			}),
+		)
+
+		// Parent set to "delegated" (second call)
+		const parentSaved = updateTaskHistory.mock.calls[1][0]
 		expect(parentSaved).toEqual(
 			expect.objectContaining({
 				id: "parent-1",
@@ -99,7 +114,10 @@ describe("ClineProvider.delegateParentAndOpenChild()", () => {
 		const callOrder: string[] = []
 
 		const parentTask = { taskId: "parent-1", emit: vi.fn() } as any
-		const childStart = vi.fn(() => callOrder.push("child.start"))
+		const childStart = vi.fn(() => {
+			callOrder.push("child.start")
+			return Promise.resolve()
+		})
 
 		const updateTaskHistory = vi.fn(async () => {
 			callOrder.push("updateTaskHistory")
@@ -130,6 +148,7 @@ describe("ClineProvider.delegateParentAndOpenChild()", () => {
 			updateTaskHistory,
 			handleModeSwitch,
 			log: vi.fn(),
+			contextProxy: { globalStorageUri: { fsPath: "/tmp" } },
 		} as unknown as ClineProvider
 
 		await (ClineProvider.prototype as any).delegateParentAndOpenChild.call(provider, {
@@ -139,7 +158,7 @@ describe("ClineProvider.delegateParentAndOpenChild()", () => {
 			mode: "code",
 		})
 
-		// Verify ordering: createTask → updateTaskHistory → child.start
-		expect(callOrder).toEqual(["createTask", "updateTaskHistory", "child.start"])
+		// Verify ordering: createTask → updateTaskHistory (child) → updateTaskHistory (parent) → child.start
+		expect(callOrder).toEqual(["createTask", "updateTaskHistory", "updateTaskHistory", "child.start"])
 	})
 })

src/__tests__/removeClineFromStack-delegation.spec.ts

@@ -1,6 +1,12 @@
 // npx vitest run __tests__/removeClineFromStack-delegation.spec.ts
 
 import { describe, it, expect, vi } from "vitest"
+
+vi.mock("../core/task-persistence/delegationMeta", () => ({
+	readDelegationMeta: vi.fn().mockResolvedValue(null),
+	saveDelegationMeta: vi.fn().mockResolvedValue(undefined),
+}))
+
 import { ClineProvider } from "../core/webview/ClineProvider"
 
 describe("ClineProvider.removeClineFromStack() delegation awareness", () => {
@@ -38,6 +44,7 @@ describe("ClineProvider.removeClineFromStack() delegation awareness", () => {
 			log: vi.fn(),
 			getTaskWithId,
 			updateTaskHistory,
+			contextProxy: { globalStorageUri: { fsPath: "/tmp" } },
 		}
 
 		return { provider, childTask, updateTaskHistory, getTaskWithId }
@@ -183,6 +190,7 @@ describe("ClineProvider.removeClineFromStack() delegation awareness", () => {
 			log: vi.fn(),
 			getTaskWithId: vi.fn(),
 			updateTaskHistory: vi.fn(),
+			contextProxy: { globalStorageUri: { fsPath: "/tmp" } },
 		}
 
 		// Should not throw
@@ -263,6 +271,7 @@ describe("ClineProvider.removeClineFromStack() delegation awareness", () => {
 			log: vi.fn(),
 			getTaskWithId,
 			updateTaskHistory,
+			contextProxy: { globalStorageUri: { fsPath: "/tmp" } },
 		}
 
 		// Simulate what delegateParentAndOpenChild does: pop B with skipDelegationRepair

src/core/assistant-message/presentAssistantMessage.ts

@@ -60,7 +60,7 @@ import { sanitizeToolUseId } from "../../utils/tool-id"
  */
 
 export async function presentAssistantMessage(cline: Task) {
-	if (cline.abort) {
+	if (cline.abort || cline.abandoned) {
 		throw new Error(`[Task#presentAssistantMessage] task ${cline.taskId}.${cline.instanceId} aborted`)
 	}
 
@@ -938,6 +938,15 @@ export async function presentAssistantMessage(cline: Task) {
 	// locked.
 	cline.presentAssistantMessageLocked = false
 
+	// Early exit if task was aborted/abandoned during tool execution (e.g., new_task delegation).
+	// Prevents unhandled promise rejections from recursive calls hitting the abort check.
+	if (cline.abort || cline.abandoned) {
+		if (cline.didCompleteReadingStream) {
+			cline.userMessageContentReady = true
+		}
+		return
+	}
+
 	// NOTE: When tool is rejected, iterator stream is interrupted and it waits
 	// for `userMessageContentReady` to be true. Future calls to present will
 	// skip execution since `didRejectTool` and iterate until `contentIndex` is
@@ -965,7 +974,11 @@ export async function presentAssistantMessage(cline: Task) {
 		if (cline.currentStreamingContentIndex < cline.assistantMessageContent.length) {
 			// There are already more content blocks to stream, so we'll call
 			// this function ourselves.
-			presentAssistantMessage(cline)
+			presentAssistantMessage(cline).catch((err) => {
+				if (!cline.abort) {
+					console.error("[presentAssistantMessage] Unhandled error:", err)
+				}
+			})
 			return
 		} else {
 			// CRITICAL FIX: If we're out of bounds and the stream is complete, set userMessageContentReady
@@ -978,7 +991,11 @@ export async function presentAssistantMessage(cline: Task) {
 
 	// Block is partial, but the read stream may have finished.
 	if (cline.presentAssistantMessageHasPendingUpdates) {
-		presentAssistantMessage(cline)
+		presentAssistantMessage(cline).catch((err) => {
+			if (!cline.abort) {
+				console.error("[presentAssistantMessage] Unhandled error:", err)
+			}
+		})
 	}
 }