fix(api): return 0 instead of throwing for unavailable task history length

Author: edelauna

apps/vscode-e2e/src/fixtures/subtasks.ts

@@ -332,7 +332,7 @@ export function addSubtaskFixtures(mock: InstanceType<typeof LLMock>) {
 			toolCalls: [
 				{
 					name: "attempt_completion",
-					arguments: JSON.stringify({ result: "9" }),
+					arguments: JSON.stringify({ result: SUBTASK_INTERRUPT_CHILD_FOLLOWUP_ANSWER }),
 					id: "call_interrupt_child_completion_002",
 				},
 			],
@@ -348,7 +348,7 @@ export function addSubtaskFixtures(mock: InstanceType<typeof LLMock>) {
 			toolCalls: [
 				{
 					name: "attempt_completion",
-					arguments: JSON.stringify({ result: "Interrupted parent resumed" }),
+					arguments: JSON.stringify({ result: SUBTASK_INTERRUPT_PARENT_RESULT }),
 					id: "call_interrupt_parent_completion_003",
 				},
 			],

src/extension/__tests__/api-task-conversation-history-length.spec.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect, vi, beforeEach } from "vitest"
+import * as vscode from "vscode"
+
+import { API } from "../api"
+import { ClineProvider } from "../../core/webview/ClineProvider"
+
+vi.mock("vscode")
+vi.mock("../../core/webview/ClineProvider")
+
+describe("API#getTaskApiConversationHistoryLength", () => {
+	let api: API
+	let mockOutputChannel: vscode.OutputChannel
+	let mockProvider: ClineProvider
+	let mockGetTaskWithId: ReturnType<typeof vi.fn>
+
+	beforeEach(() => {
+		mockOutputChannel = {
+			appendLine: vi.fn(),
+		} as unknown as vscode.OutputChannel
+
+		mockGetTaskWithId = vi.fn()
+
+		mockProvider = {
+			context: {} as vscode.ExtensionContext,
+			getTaskWithId: mockGetTaskWithId,
+			on: vi.fn(),
+		} as unknown as ClineProvider
+
+		api = new API(mockOutputChannel, mockProvider, undefined, true)
+	})
+
+	it("returns the persisted api conversation history length", async () => {
+		mockGetTaskWithId.mockResolvedValue({
+			apiConversationHistory: [{ role: "user" }, { role: "assistant" }],
+		})
+
+		await expect(api.getTaskApiConversationHistoryLength("task-1")).resolves.toBe(2)
+	})
+
+	it("returns 0 instead of throwing when the task is unavailable", async () => {
+		mockGetTaskWithId.mockRejectedValue(new Error("Task not found"))
+
+		await expect(api.getTaskApiConversationHistoryLength("missing-task")).resolves.toBe(0)
+	})
+})

src/extension/api.ts

@@ -240,9 +240,13 @@ export class API extends EventEmitter<RooCodeEvents> implements RooCodeAPI {
 		return item ? structuredClone(item) : undefined
 	}
 
-	public async getTaskApiConversationHistoryLength(taskId: string) {
-		const { apiConversationHistory } = await this.sidebarProvider.getTaskWithId(taskId)
-		return apiConversationHistory.length
+	public async getTaskApiConversationHistoryLength(taskId: string): Promise<number> {
+		try {
+			const { apiConversationHistory } = await this.sidebarProvider.getTaskWithId(taskId)
+			return apiConversationHistory.length
+		} catch {
+			return 0
+		}
 	}
 
 	public getCurrentTaskStack() {