test(e2e): port view-state suite with reload and rehydration coverage

Port source: CS e9a44b2 apps/vscode-e2e (A5 #929 re-review series) — 3 files byte-identical, 2 suite tests
F6-authored: sidebar webview reload/rehydration test (A5 minor 2) — the durable per-view mode survives a sidebar hide/show cycle

Author: easonliang28

apps/vscode-e2e/fixtures/modes.json

@@ -13,6 +13,20 @@
 					}
 				]
 			}
+		},
+		{
+			"match": {
+				"userMessage": "Use the `switch_mode` tool to switch to debug mode."
+			},
+			"response": {
+				"toolCalls": [
+					{
+						"name": "switch_mode",
+						"arguments": "{\"mode_slug\":\"debug\",\"reason\":\"User requested to switch to debug mode.\"}",
+						"id": "call_modes_switch_002"
+					}
+				]
+			}
 		}
 	]
 }

apps/vscode-e2e/src/fixtures/view-state.ts

@@ -0,0 +1,95 @@
+import type { ChatCompletionRequest, ChatMessage, LLMock } from "@copilotkit/aimock"
+
+const TASKS = ["A", "B", "C"] as const
+const ROUNDS = 10
+
+const MODE_SEQUENCES: Record<(typeof TASKS)[number], string[]> = {
+	A: ["ask", "debug", "architect", "orchestrator", "code", "ask", "debug", "architect", "orchestrator", "code"],
+	B: ["debug", "architect", "orchestrator", "code", "ask", "debug", "architect", "orchestrator", "code", "ask"],
+	C: ["architect", "orchestrator", "code", "ask", "debug", "architect", "orchestrator", "code", "ask", "debug"],
+}
+
+const markerFor = (taskName: (typeof TASKS)[number]) => `FOLLOWUP_MODE_ISOLATION_${taskName}`
+const answerFor = (taskName: (typeof TASKS)[number], round: number) => `${taskName} follow-up round ${round}`
+const callIdFor = (taskName: (typeof TASKS)[number], round: number) =>
+	`call_followup_mode_${taskName.toLowerCase()}_${String(round).padStart(2, "0")}`
+
+const lastToolResultContains = (req: ChatCompletionRequest, toolCallId: string, expected: string[]) => {
+	const messages = Array.isArray(req?.messages) ? req.messages : []
+	const toolMessage = messages.filter((message: ChatMessage) => message?.role === "tool").at(-1)
+	const content = toolMessage?.content
+
+	return (
+		toolMessage?.tool_call_id === toolCallId &&
+		typeof content === "string" &&
+		expected.every((text) => content.includes(text))
+	)
+}
+
+const followupToolCall = (taskName: (typeof TASKS)[number], round: number) => ({
+	name: "ask_followup_question",
+	arguments: JSON.stringify({
+		question: `Task ${taskName}: choose mode for round ${round}`,
+		follow_up: [
+			{
+				text: answerFor(taskName, round),
+				mode: MODE_SEQUENCES[taskName][round - 1],
+			},
+		],
+	}),
+	id: callIdFor(taskName, round),
+})
+
+export const getFollowupModeIsolationPlan = () =>
+	TASKS.map((taskName) => ({
+		taskName,
+		marker: markerFor(taskName),
+		rounds: MODE_SEQUENCES[taskName].map((mode, index) => ({
+			round: index + 1,
+			answer: answerFor(taskName, index + 1),
+			mode,
+		})),
+	}))
+
+export function addViewStateFixtures(mock: InstanceType<typeof LLMock>) {
+	for (const taskName of TASKS) {
+		mock.addFixture({
+			match: {
+				userMessage: markerFor(taskName),
+			},
+			response: {
+				toolCalls: [followupToolCall(taskName, 1)],
+			},
+		})
+
+		for (let round = 1; round < ROUNDS; round++) {
+			mock.addFixture({
+				match: {
+					predicate: (req) =>
+						lastToolResultContains(req, callIdFor(taskName, round), [answerFor(taskName, round)]),
+				},
+				response: {
+					toolCalls: [followupToolCall(taskName, round + 1)],
+				},
+			})
+		}
+
+		mock.addFixture({
+			match: {
+				predicate: (req) =>
+					lastToolResultContains(req, callIdFor(taskName, ROUNDS), [answerFor(taskName, ROUNDS)]),
+			},
+			response: {
+				toolCalls: [
+					{
+						name: "attempt_completion",
+						arguments: JSON.stringify({
+							result: `Task ${taskName} completed ${ROUNDS} follow-up mode switches.`,
+						}),
+						id: `call_followup_mode_${taskName.toLowerCase()}_complete`,
+					},
+				],
+			},
+		})
+	}
+}

apps/vscode-e2e/src/runTest.ts

@@ -23,6 +23,8 @@ import { addUseMcpToolResultFixtures } from "./fixtures/use-mcp-tool"
 import { addWriteToFileResultFixtures } from "./fixtures/write-to-file"
 import { createScenarioWorkspace, removeScenarioWorkspace } from "./restart/scenarioWorkspace"
 import { runRestartScenario } from "./restart/vscodeCoordinator"
+import { toolResultContains } from "./fixtures/tool-result"
+import { addViewStateFixtures } from "./fixtures/view-state"
 
 function getCliFlagValue(flag: string) {
 	return process.argv.find((arg, index) => process.argv[index - 1] === flag)
@@ -143,6 +145,41 @@ async function main() {
 				addUseMcpToolResultFixtures(mock)
 				addWriteToFileResultFixtures(mock)
 				addDeepSeekV4Fixtures(mock)
+				addViewStateFixtures(mock)
+
+				// Model-agnostic predicate fixtures for the view-state suite's post-switch
+				// turns. They coexist with the legacy model-scoped regex fixture below
+				// (shared response id call_modes_post_switch_001) so the modes suite keeps
+				// its OpenRouter-scoped match while view-state runs under any default model.
+				mock.addFixture({
+					match: {
+						predicate: (req) => toolResultContains(req, "call_modes_switch_001", []),
+					},
+					response: {
+						toolCalls: [
+							{
+								name: "attempt_completion",
+								arguments: JSON.stringify({ result: "Switched to ❓ Ask mode as requested." }),
+								id: "call_modes_post_switch_001",
+							},
+						],
+					},
+				})
+
+				mock.addFixture({
+					match: {
+						predicate: (req) => toolResultContains(req, "call_modes_switch_002", []),
+					},
+					response: {
+						toolCalls: [
+							{
+								name: "attempt_completion",
+								arguments: JSON.stringify({ result: "Switched to 🪲 Debug mode as requested." }),
+								id: "call_modes_post_switch_002",
+							},
+						],
+					},
+				})
 
 				// The modes test (switch_mode → ask) triggers a second API call whose last
 				// user message starts with <environment_details> directly — no <user_message>