PaperClipAI/packages/paperclip-runner/src/drivers/opencode/opencode-server-driver.test.ts

import {
  chmod,
  copyFile,
  lstat,
  mkdir,
  mkdtemp,
  readFile,
  readdir,
  realpath,
  rm,
  stat,
  symlink,
  writeFile,
} from "node:fs/promises";
import { tmpdir } from "node:os";
import { createServer as createHttpServer } from "node:http";
import { execFile, type ChildProcess } from "node:child_process";
import { EventEmitter } from "node:events";
import { promisify } from "node:util";
import { getCACertificates } from "node:tls";
import { basename, dirname, join, resolve } from "node:path";
import { afterAll, afterEach, beforeAll, describe, expect, it } from "vitest";

import {
  NATIVE_RUNTIME_ASSET_SCHEMA,
  PAPERCLIP_EXECUTION_PROMPT,
  PAPERCLIP_EXECUTION_PROMPT_REVISION,
  canonicalNativeRuntimeContextDigest,
  nativeRuntimePromptDigest,
  type NativeRuntimeContextSnapshot,
} from "../../contracts/runtime-context.js";
import { createCodexTaskEnvelope } from "../../contracts/codex.js";
import { localIntegrityBoundaryGolden } from "../../../test-support/local-integrity-boundary-golden.js";
import type { PrpEvent } from "../../protocol/replay-contract.js";
import {
  OpenCodeServerDriver,
  openCodeServerDriverInternals,
} from "./opencode-server-driver.js";

const roots: string[] = [];
let fixtureRoot: string | undefined;
let fixture: string;

beforeAll(async () => {
  fixtureRoot = await mkdtemp(join(tmpdir(), "paperclip-opencode-fixture-"));
  fixture = join(fixtureRoot, "fake-opencode-server.mjs");
  await copyFile(resolve("test/fixtures/fake-opencode-server.mjs"), fixture);
});

const TURN_TERMINAL_EVENT_TYPES = new Set([
  "turn.completed",
  "turn.failed",
  "turn.interrupted",
  "turn.cancelled",
]);

/**
 * The session event stream stays open past a turn boundary so a session can
 * run more turns. Read one turn's events by stopping at its terminal event,
 * the same rule the production consumer applies.
 */
async function collectTurnEvents(
  events: AsyncIterable<PrpEvent>,
): Promise<PrpEvent[]> {
  const collected: PrpEvent[] = [];
  for await (const event of events) {
    collected.push(event);
    if (TURN_TERMINAL_EVENT_TYPES.has(event.eventType)) break;
  }
  return collected;
}

function runtimeContext(
  skillRoot: string,
  instructionRoot: string,
): NativeRuntimeContextSnapshot {
  const digest = "0".repeat(64);
  const value = {
    prompt: {
      revision: PAPERCLIP_EXECUTION_PROMPT_REVISION,
      text: PAPERCLIP_EXECUTION_PROMPT,
      digest: nativeRuntimePromptDigest(),
    },
    instructions: {
      entryPath: "AGENTS.md",
      bundle: {
        schema: NATIVE_RUNTIME_ASSET_SCHEMA,
        digest,
        manifestDigest: digest,
        rootPath: instructionRoot,
        fileCount: 2,
        totalBytes: 2,
      },
    },
    skills: [
      {
        key: "company/assigned",
        runtimeName: "assigned",
        versionId: "version-1",
        bundle: {
          schema: NATIVE_RUNTIME_ASSET_SCHEMA,
          digest,
          manifestDigest: digest,
          rootPath: skillRoot,
          fileCount: 2,
          totalBytes: 2,
        },
      },
    ],
    mcp: { assignmentSetId: "assigned", digest, bindingId: "binding" },
  } satisfies Omit<NativeRuntimeContextSnapshot, "aggregateDigest">;
  return {
    ...value,
    aggregateDigest: canonicalNativeRuntimeContextDigest(value),
  };
}

async function makeWritable(root: string): Promise<void> {
  const info = await lstat(root).catch(() => null);
  if (!info) return;
  if (info.isDirectory()) {
    await chmod(root, 0o700);
    for (const entry of await readdir(root))
      await makeWritable(join(root, entry));
  } else {
    await chmod(root, 0o600);
  }
}

afterEach(async () => {
  await Promise.all(
    roots.splice(0).map(async (root) => {
      await makeWritable(root);
      await rm(root, { recursive: true, force: true });
    }),
  );
});

afterAll(async () => {
  if (fixtureRoot) await rm(fixtureRoot, { recursive: true, force: true });
});

describe("OpenCodeServerDriver", () => {
  it("advertises within-turn plans as unsupported", async () => {
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: "/tmp/paperclip-opencode-capabilities",
      command: fixture,
    });
    const descriptor = await driver.descriptor();
    expect(
      descriptor.capabilities.typedEventFamilies.find(
        (family) => family.family === "plan",
      ),
    ).toMatchObject({ availability: "unsupported" });
  });

  it("normalizes raw OpenCode boundary events into the local-integrity golden identities", async () => {
    await chmod(fixture, 0o755);
    const profile = localIntegrityBoundaryGolden.profiles.find(
      (candidate) => candidate.id === "runner-opencode",
    );
    if (!profile) throw new Error("missing runner-opencode golden profile");
    const goldenEvent = (sourceEventId: string) => {
      const event = localIntegrityBoundaryGolden.events.find(
        (candidate) => candidate.sourceEventId === sourceEventId,
      );
      if (!event) throw new Error(`missing golden event ${sourceEventId}`);
      return event;
    };
    const progress = localIntegrityBoundaryGolden.expected.assistantItems.find(
      (item) => item.channel === "progress",
    );
    const final = localIntegrityBoundaryGolden.expected.assistantItems.find(
      (item) => item.channel === "final",
    );
    if (!progress || !final)
      throw new Error("missing golden assistant messages");

    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-boundary-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-boundary-workspace-"),
    );
    roots.push(root, workspace);
    const tracePath = join(root, "provider-trace.ndjson");
    const providerSessionId = "provider-session-boundary";
    const nativeEvents: Array<Record<string, unknown>> = [];
    const queuedFrames: Uint8Array[] = [];
    const encoder = new TextEncoder();
    let streamController: ReadableStreamDefaultController<Uint8Array> | null =
      null;
    let streamClosed = false;
    const emitNative = (event: Record<string, unknown>) => {
      nativeEvents.push(structuredClone(event));
      const frame = encoder.encode(`data: ${JSON.stringify(event)}\n\n`);
      if (streamController) streamController.enqueue(frame);
      else queuedFrames.push(frame);
    };
    const closeNativeStream = () => {
      streamClosed = true;
      streamController?.close();
    };
    const nativeQuestion = {
      type: "question.asked",
      id: "native-question-created",
      properties: {
        id: localIntegrityBoundaryGolden.expected.questionRequestId,
        sessionID: providerSessionId,
        title: "Boundary mode",
        questions: [
          {
            id: "boundary-mode",
            question: "Which mode should continue?",
            required: true,
            options: [{ id: "lossless", label: "Lossless" }],
          },
        ],
      },
    } satisfies Record<string, unknown>;
    const emitBeforeQuestion = () => {
      emitNative({
        type: "message.updated",
        id: "native-progress-message-role",
        properties: {
          info: {
            id: "provider-message-progress",
            sessionID: providerSessionId,
            role: "assistant",
          },
        },
      });
      emitNative({
        type: "message.part.updated",
        id: "native-progress-part",
        properties: {
          sessionID: providerSessionId,
          part: {
            id: progress.itemId,
            messageID: "provider-message-progress",
            type: "text",
            text: progress.text,
            time: { start: 1, end: 2 },
          },
        },
      });
      emitNative({
        type: "message.part.updated",
        id: "native-reasoning-part",
        properties: {
          sessionID: providerSessionId,
          part: {
            id: localIntegrityBoundaryGolden.expected.reasoningItemId,
            messageID: "provider-message-progress",
            type: "reasoning",
            text: "Verified event identity.",
            time: { start: 2, end: 3 },
          },
        },
      });
      for (const [id, status, state] of [
        ["native-tool-started", "pending", { title: "Inspecting" }],
        ["native-tool-progressed", "running", { title: "Inspecting" }],
        [
          "native-tool-completed",
          "completed",
          { output: "boundary-ok", time: 12, exit: 0 },
        ],
      ] as const) {
        emitNative({
          type: "message.part.updated",
          id,
          properties: {
            sessionID: providerSessionId,
            part: {
              id: localIntegrityBoundaryGolden.expected.toolExecutionId,
              messageID: "provider-message-progress",
              type: "tool",
              tool: "boundary-check",
              state: { status, ...state },
            },
          },
        });
      }
      emitNative(nativeQuestion);
    };
    const emitAfterQuestion = () => {
      emitNative({
        ...nativeQuestion,
        id: "native-question-resolved",
        type: "question.replied",
      });
      emitNative({
        type: "message.updated",
        id: "native-final-message-role",
        properties: {
          info: {
            id: "provider-message-final",
            sessionID: providerSessionId,
            role: "assistant",
          },
        },
      });
      emitNative({
        type: "message.part.updated",
        id: "native-final-part",
        properties: {
          sessionID: providerSessionId,
          part: {
            id: final.itemId,
            messageID: "provider-message-final",
            type: "text",
            text: final.text,
            time: { start: 4, end: 5 },
          },
        },
      });
      emitNative({
        type: "message.updated",
        id: "native-usage",
        properties: {
          info: {
            id: "provider-message-final",
            sessionID: providerSessionId,
            role: "assistant",
            tokens: {
              input: 40,
              output: 12,
              cache: { read: 3, write: 0 },
            },
            cost: 0.02,
          },
        },
      });
      emitNative({
        type: "session.idle",
        id: "native-turn-completed",
        properties: { sessionID: providerSessionId },
      });
      closeNativeStream();
    };
    let submittedQuestionReply: unknown = null;
    const fetcher: typeof globalThis.fetch = async (input, init) => {
      const url = new URL(String(input));
      const method = String(init?.method ?? "GET").toUpperCase();
      const json = (value: unknown, status = 200) =>
        new Response(JSON.stringify(value), {
          status,
          headers: { "Content-Type": "application/json" },
        });
      if (url.pathname === "/global/health")
        return json({ healthy: true, version: "1.18.34" });
      if (url.pathname === "/event") {
        return new Response(
          new ReadableStream<Uint8Array>({
            start(controller) {
              streamController = controller;
              for (const frame of queuedFrames.splice(0))
                controller.enqueue(frame);
              if (streamClosed) controller.close();
            },
          }),
          { status: 200, headers: { "Content-Type": "text/event-stream" } },
        );
      }
      if (method === "POST" && url.pathname === "/session")
        return json({ id: providerSessionId });
      if (method === "GET" && url.pathname === "/question") return json([]);
      if (method === "GET" && url.pathname === "/permission") return json([]);
      if (
        method === "POST" &&
        url.pathname === `/session/${providerSessionId}/prompt_async`
      ) {
        emitBeforeQuestion();
        return new Response(null, { status: 204 });
      }
      if (
        method === "POST" &&
        url.pathname ===
          `/question/${localIntegrityBoundaryGolden.expected.questionRequestId}/reply`
      ) {
        submittedQuestionReply = JSON.parse(String(init?.body));
        emitAfterQuestion();
        return json(true);
      }
      if (
        method === "POST" &&
        url.pathname === `/session/${providerSessionId}/abort`
      )
        return json(true);
      throw new Error(`unexpected OpenCode boundary request ${method} ${url}`);
    };
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      runnerInstanceId: profile.sourceInstanceId,
      fetch: fetcher,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
        PAPERCLIP_PROVIDER_TRACE_PATH: tracePath,
      },
    });
    const session = await driver.openSession({
      runId: profile.runId,
      normalizedSessionId: profile.normalizedSessionId,
      workingDirectory: workspace,
    });
    const { turnId } = await session.startTurn({
      message: { role: "user", text: "exercise native golden boundary" },
    });
    const events = [];
    const iterator = session.events()[Symbol.asyncIterator]();
    let requestCreated = false;
    while (!requestCreated) {
      const next = await iterator.next();
      if (next.done)
        throw new Error("OpenCode ended before asking its question");
      events.push(next.value);
      requestCreated = next.value.eventType === "runtime_request.created";
    }
    await session.resolveRuntimeRequest?.({
      requestId: localIntegrityBoundaryGolden.expected.questionRequestId,
      turnId,
      resolution: {
        action: "submit",
        response: {
          schema: "paperclip.question_response.v1",
          answers: {
            "boundary-mode": { selectedOptionIds: ["lossless"] },
          },
        },
      },
    });
    for (;;) {
      const next = await iterator.next();
      if (next.done) break;
      events.push(next.value);
      if (TURN_TERMINAL_EVENT_TYPES.has(next.value.eventType)) break;
    }
    await session.close({ reason: "boundary-golden-test" });

    expect(submittedQuestionReply).toEqual({ answers: [["Lossless"]] });
    expect(
      events.every(
        (event) =>
          event.runId === profile.runId &&
          event.normalizedSessionId === profile.normalizedSessionId,
      ),
    ).toBe(true);
    expect(events).toContainEqual(
      expect.objectContaining({
        itemId: progress.itemId,
        eventType: "item.delta",
        payload: expect.objectContaining({
          kind: "agentMessage",
          channel: progress.channel,
          providerPhase: "commentary",
          text: progress.text,
        }),
      }),
    );
    expect(events).toContainEqual(
      expect.objectContaining({
        itemId: localIntegrityBoundaryGolden.expected.reasoningItemId,
        eventType: "item.completed",
        payload: expect.objectContaining({
          kind: "reasoning",
          channel: "detail",
          providerPhase: "reasoning",
          text: String(goldenEvent("reasoning-completed").payload.text),
        }),
      }),
    );
    expect(
      events
        .filter(
          (event) =>
            event.itemId ===
              localIntegrityBoundaryGolden.expected.toolExecutionId &&
            event.eventType.startsWith("tool.execution."),
        )
        .map((event) => [event.eventType, event.payload.status]),
    ).toEqual([
      ["tool.execution.started", "running"],
      ["tool.execution.progressed", "running"],
      ["tool.execution.completed", "completed"],
    ]);
    expect(events).toContainEqual(
      expect.objectContaining({
        itemId: localIntegrityBoundaryGolden.expected.questionRequestId,
        eventType: "runtime_request.created",
        payload: {
          request: expect.objectContaining({
            requestId: localIntegrityBoundaryGolden.expected.questionRequestId,
            origin: {
              adapter: profile.adapter,
              provider: profile.originProvider,
              method: profile.originMethod,
            },
            input: expect.objectContaining({
              schema: "paperclip.question_set.v1",
              title: "Boundary mode",
              questions: [
                expect.objectContaining({
                  id: "boundary-mode",
                  answerMode: "single_select",
                }),
              ],
            }),
          }),
        },
      }),
    );
    expect(
      events.filter(
        (event) =>
          event.itemId ===
            localIntegrityBoundaryGolden.expected.questionRequestId &&
          event.eventType === "runtime_request.resolved",
      ),
    ).toHaveLength(1);
    expect(events).toContainEqual(
      expect.objectContaining({
        itemId: final.itemId,
        eventType: "item.completed",
        payload: expect.objectContaining({
          kind: "agentMessage",
          channel: final.channel,
          providerPhase: "final_answer",
          text: final.text,
        }),
      }),
    );
    expect(
      events.find(
        (event) =>
          event.eventType === "item.completed" &&
          event.payload.kind === "usage",
      ),
    ).toMatchObject({
      itemId: `${turnId}:usage`,
      payload: {
        usageMessageId: "provider-message-final",
        usage: {
          input: 40,
          output: 12,
          cache: { read: 3, write: 0 },
          costUsd: 0.02,
        },
      },
    });
    expect(events).toContainEqual(
      expect.objectContaining({
        eventType: "turn.completed",
        turnId,
        payload: { status: "completed" },
      }),
    );

    // OpenCode 1.18 does not expose a qualified structured Plan event, and
    // run.terminal is owned by the native-session layer above this driver.
    // Keep both absences explicit instead of synthesizing Codex-shaped input.
    expect(
      (await driver.descriptor()).capabilities.typedEventFamilies.find(
        (family) => family.family === "plan",
      ),
    ).toMatchObject({ availability: "unsupported" });
    expect(events.some((event) => event.eventType === "plan.updated")).toBe(
      false,
    );
    expect(events.some((event) => event.eventType === "run.terminal")).toBe(
      false,
    );

    const traceEntries = (await readFile(tracePath, "utf8"))
      .trim()
      .split("\n")
      .map((line) => JSON.parse(line) as Record<string, unknown>);
    const traceFrames = traceEntries.filter(
      (entry) =>
        entry.kind === "frame" && entry.direction === "provider_to_client",
    );
    const normalization = traceEntries.filter(
      (entry) =>
        entry.kind === "interpretation" &&
        entry.stage === "typescript_opencode_driver_normalization",
    );
    expect(nativeEvents.map((event) => event.type)).toEqual([
      "message.updated",
      "message.part.updated",
      "message.part.updated",
      "message.part.updated",
      "message.part.updated",
      "message.part.updated",
      "question.asked",
      "question.replied",
      "message.updated",
      "message.part.updated",
      "message.updated",
      "session.idle",
    ]);
    for (const nativeEvent of nativeEvents) {
      const frame = traceFrames.find((entry) => {
        if (typeof entry.rawBase64 !== "string") return false;
        const raw = Buffer.from(entry.rawBase64, "base64").toString("utf8");
        return raw.includes(`\"id\":\"${String(nativeEvent.id)}\"`);
      });
      expect(frame, String(nativeEvent.id)).toBeDefined();
      const interpretation = normalization.find(
        (entry) => entry.frameId === frame?.frameId,
      );
      expect(interpretation, String(nativeEvent.id)).toMatchObject({
        disposition: expect.stringMatching(/^(mapped|ignored)$/),
      });
      if (interpretation?.disposition === "ignored") {
        expect(
          [
            "native-progress-message-role",
            "native-final-message-role",
            "native-question-resolved",
          ],
          `${String(nativeEvent.id)} must be a structural or duplicate echo`,
        ).toContain(nativeEvent.id);
      }
    }
  });

  it("projects a custom connection into the isolated OpenCode config", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-routing-"));
    roots.push(root);
    const driver = new OpenCodeServerDriver({
      model: "paperclip/team/model-alias",
      runtimeDirectory: root,
      command: fixture,
      environment: { PATH: process.env.PATH, PAPERCLIP_AI_PROVIDER_URL: "https://gateway.example/v1", PAPERCLIP_AI_PROVIDER_KEY: "selected-gateway-key" },
    });
    const session = await driver.openSession({ runId: "routing", normalizedSessionId: "routing", workingDirectory: root });
    try {
      const configPath = join(root, "routing", "config", "opencode", "opencode.json");
      expect(JSON.parse(await readFile(configPath, "utf8"))).toMatchObject({
        model: "paperclip/team/model-alias", small_model: "paperclip/team/model-alias", plugin: [],
        provider: { paperclip: { npm: "@ai-sdk/openai-compatible", options: { baseURL: expect.stringMatching(/^http:\/\/127\.0\.0\.1:\d+\/v1$/), apiKey: expect.any(String) }, models: { "team/model-alias": { name: "team/model-alias" } } } },
      });
      expect((await stat(configPath)).mode & 0o777).toBe(0o600);
      const shell = await promisify(execFile)("sh", ["-c", 'cat "$1"', "sh", configPath]);
      expect(shell.stdout).not.toContain("selected-gateway-key");
      const environment = JSON.parse(await readFile(join(root, "routing", "data", "fake-environment.json"), "utf8"));
      expect(environment.keys).not.toContain("PAPERCLIP_AI_PROVIDER_KEY");
    } finally {
      await session.close({ reason: "test" });
    }
  });

  it.each(["gateway-key", ""])("forwards selected-model streams without exposing the reusable key and revokes the proxy on close (%s)", async key => {
    const received: Array<{ path: string; authorization?: string; body: unknown }> = [];
    const upstream = createHttpServer((request, response) => {
      void (async () => {
        const chunks = [];
        for await (const chunk of request) chunks.push(Buffer.from(chunk));
        const body = JSON.parse(Buffer.concat(chunks).toString("utf8"));
        received.push({ path: request.url!, authorization: request.headers.authorization, body });
        response.writeHead(200, { "content-type": "text/event-stream", "x-provider-private-header": "private" });
        response.write('data: {"choices":[]}\n\n');
        if (body.messages[0].content !== "hold") response.end('data: [DONE]\n\n');
      })().catch(() => response.destroy());
    });
    await new Promise<void>(resolve => upstream.listen(0, "127.0.0.1", resolve));
    const address = upstream.address();
    if (!address || typeof address === "string") throw new Error("Missing fixture address");
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-proxy-"));
    roots.push(root);
    let session: Awaited<ReturnType<OpenCodeServerDriver["openSession"]>> | undefined;
    try {
      const driver = new OpenCodeServerDriver({
        model: "paperclip/team/model-alias", runtimeDirectory: root, command: fixture,
        environment: { PATH: process.env.PATH, PAPERCLIP_AI_PROVIDER_URL: `http://127.0.0.1:${address.port}/custom/v1`, PAPERCLIP_AI_PROVIDER_KEY: key },
      });
      session = await driver.openSession({ runId: "proxy", normalizedSessionId: "proxy", workingDirectory: root });
      const config = JSON.parse(await readFile(join(root, "proxy", "config", "opencode", "opencode.json"), "utf8"));
      const { baseURL, apiKey } = config.provider.paperclip.options;
      expect(apiKey).not.toBe(key);
      const url = `${baseURL}/chat/completions`;
      const headers = { Authorization: `Bearer ${apiKey}`, "Content-Type": "application/json" };
      const payload = { model: "team/model-alias", stream: true, messages: [{ role: "user", content: "test" }] };
      expect((await fetch(url, { method: "POST", body: JSON.stringify(payload) })).status).toBe(401);
      expect((await fetch(`${baseURL}/models`, { headers })).status).toBe(404);
      expect((await fetch(url, { method: "POST", headers, body: JSON.stringify({ ...payload, model: "other" }) })).status).toBe(400);
      expect(received).toHaveLength(0);
      const result = await fetch(url, { method: "POST", headers, body: JSON.stringify(payload) });
      expect(result.headers.get("x-provider-private-header")).toBeNull();
      expect(await result.text()).toBe('data: {"choices":[]}\n\ndata: [DONE]\n\n');
      expect(received).toEqual([{ path: "/custom/v1/chat/completions", authorization: key ? `Bearer ${key}` : undefined, body: payload }]);
      const pending = await fetch(url, { method: "POST", headers, body: JSON.stringify({ ...payload, messages: [{ role: "user", content: "hold" }] }) });
      const pendingText = pending.text().then(() => "unexpected completion", () => "aborted");
      await session.close({ reason: "test" });
      session = undefined;
      expect(await pendingText).toBe("aborted");
      await expect(fetch(url, { method: "POST", headers, body: JSON.stringify(payload) })).rejects.toThrow();
    } finally {
      await session?.close({ reason: "test" });
      await new Promise<void>(resolve => { upstream.close(() => resolve()); upstream.closeAllConnections(); });
    }
  });

  it.each([["HTTP_PROXY", "file"], ["ALL_PROXY", "directory"]] as const)("uses the runtime's %s, %s trust, and NO_PROXY without changing global transport", async (proxySetting, trust) => {
    const requests: string[] = [];
    const outgoingProxy = createHttpServer((request, response) => {
      requests.push(request.url!);
      request.resume();
      response.writeHead(200, { "content-type": "application/json" }).end('{"choices":[]}');
    });
    await new Promise<void>(resolve => outgoingProxy.listen(0, "127.0.0.1", resolve));
    const address = outgoingProxy.address();
    if (!address || typeof address === "string") throw new Error("Missing proxy fixture address");
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-outgoing-proxy-"));
    roots.push(root);
    const certificateDir = join(root, "certificates");
    await mkdir(certificateDir);
    const certificatePath = join(certificateDir, "runtime-ca.pem");
    await writeFile(certificatePath, getCACertificates("default")[0]!);
    await writeFile(join(certificateDir, "README"), "Non-certificate directory entries must be ignored.");
    const trustEnvironment = trust === "file" ? { SSL_CERT_FILE: certificatePath } : { SSL_CERT_DIR: certificateDir };
    const headersAndUrl = async (sessionId: string, noProxy: string) => {
      const driver = new OpenCodeServerDriver({
        model: "paperclip/team/model-alias", runtimeDirectory: root, command: fixture,
        environment: { ...trustEnvironment, PATH: process.env.PATH, PAPERCLIP_AI_PROVIDER_URL: "http://gateway.invalid/v1", PAPERCLIP_AI_PROVIDER_KEY: "fixture-key", [proxySetting]: `http://127.0.0.1:${address.port}`, NO_PROXY: noProxy },
      });
      const session = await driver.openSession({ runId: sessionId, normalizedSessionId: sessionId, workingDirectory: root });
      const config = JSON.parse(await readFile(join(root, sessionId, "config", "opencode", "opencode.json"), "utf8"));
      return { session, url: `${config.provider.paperclip.options.baseURL}/chat/completions`, headers: { Authorization: `Bearer ${config.provider.paperclip.options.apiKey}`, "Content-Type": "application/json" } };
    };
    try {
      const proxied = await headersAndUrl("proxied", "");
      try {
        const response = await fetch(proxied.url, { method: "POST", headers: proxied.headers, body: JSON.stringify({ model: "team/model-alias", messages: [] }) });
        expect(response.status).toBe(200);
        expect(await response.json()).toEqual({ choices: [] });
        expect(requests).toEqual(["http://gateway.invalid/v1/chat/completions"]);
      } finally { await proxied.session.close({ reason: "test" }); }
      const bypassed = await headersAndUrl("bypassed", "gateway.invalid");
      try {
        const response = await fetch(bypassed.url, { method: "POST", headers: bypassed.headers, body: JSON.stringify({ model: "team/model-alias", messages: [] }) });
        expect(response.status).toBe(502);
        expect(requests).toHaveLength(1);
      } finally { await bypassed.session.close({ reason: "test" }); }
    } finally {
      await new Promise<void>(resolve => { outgoingProxy.close(() => resolve()); outgoingProxy.closeAllConnections(); });
    }
  });

  it("starts an authenticated isolated server, creates a session, streams usage, aborts, and cleans up", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const tracePath = join(root, "provider-trace.ndjson");
    const spawns: Array<{ pid: number; processGroupId: number | null }> = [];
    const diagnostics: string[] = [];
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "test-openrouter-key",
        PAPERCLIP_API_KEY: "must-not-leak",
        UNRELATED_SECRET: "must-not-leak",
        PAPERCLIP_PROVIDER_TRACE_PATH: tracePath,
        PAPERCLIP_PROVIDER_TRACE_MAX_BYTES: String(64 * 1024 * 1024),
      },
      onSpawn: async (meta) => {
        spawns.push(meta);
      },
      onDiagnostic: (message) => diagnostics.push(message),
    });
    const session = await driver.openSession({
      runId: "run-1",
      normalizedSessionId: "normalized/1",
      workingDirectory: workspace,
    });
    expect(session.ids()).toMatchObject({ providerSessionId: "ses_fake_1" });
    expect(spawns).toHaveLength(1);
    const turn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    const events = await collectTurnEvents(session.events());
    expect(events.map((event) => event.eventType)).toContain("turn.completed");
    expect(events).toContainEqual(
      expect.objectContaining({ eventType: "run.result.proposed" }),
    );
    expect(
      events.filter((event) => event.eventType === "item.delta"),
    ).toHaveLength(1);
    expect(
      events.find((event) => event.eventType === "item.delta")?.payload.text,
    ).toBe("done [guide](guide.md)");
    expect(
      events.find(
        (event) =>
          event.eventType === "item.completed" &&
          event.payload.kind === "agentMessage",
      )?.payload,
    ).toMatchObject({
      channel: "final",
      providerPhase: "final_answer",
      text: "done [guide](guide.md)",
    });
    const usageEvents = events.filter(
      (event) =>
        event.eventType === "item.completed" && event.payload.kind === "usage",
    );
    expect(usageEvents).toHaveLength(1);
    expect(usageEvents[0]?.payload).toMatchObject({
      usageMessageId: expect.any(String),
    });
    expect(
      events.find((event) => event.eventType === "workspace.change.updated")
        ?.payload,
    ).toMatchObject({
      schema: "paperclip.workspace.diff.v1",
      source: "harness_reported",
      totals: { files: 1 },
    });
    expect(
      events.find((event) => event.eventType === "workspace.diff.recorded")
        ?.payload,
    ).toMatchObject({ schema: "paperclip.workspace.diff.v1", complete: true });
    expect(
      events.find((event) => event.eventType === "workspace.file.referenced")
        ?.payload,
    ).toMatchObject({
      schema: "paperclip.workspace.file_reference.v1",
      path: "guide.md",
    });
    expect(JSON.stringify(events)).not.toContain(
      "submitted prompt must not become assistant text",
    );
    expect(await session.usage()).toMatchObject({
      input: 3,
      output: 2,
      costUsd: 0.001,
      provider: "openrouter",
      driverVersion: "1.18.34",
    });
    await session.interrupt?.({ turnId: turn.turnId });
    const snapshot = await session.snapshot();
    expect(snapshot.driverKind).toBe("opencode_server");
    const sessionRoot = join(root, "normalized_1");
    expect((await stat(sessionRoot)).mode & 0o777).toBe(0o700);
    expect(
      (await stat(join(sessionRoot, "config", "opencode", "opencode.json")))
        .mode & 0o777,
    ).toBe(0o600);
    const config = await readFile(
      join(sessionRoot, "config", "opencode", "opencode.json"),
      "utf8",
    );
    await session.close({ reason: "test" });
    const recovered = await driver.recoverSession?.(snapshot);
    expect(recovered).toMatchObject({ recovered: true });
    await expect(recovered?.session?.read?.()).resolves.toMatchObject({
      sessionId: "ses_fake_1",
      messages: [],
    });
    await recovered?.session?.close({ reason: "recovery-test" });

    const traceEntries = (await readFile(tracePath, "utf8"))
      .trim()
      .split("\n")
      .map((line) => JSON.parse(line) as Record<string, unknown>);
    expect(JSON.stringify(traceEntries)).not.toContain("test-openrouter-key");
    const traceFrames = traceEntries.filter((entry) => entry.kind === "frame");
    expect(traceFrames.map((entry) => entry.direction)).toEqual(
      expect.arrayContaining([
        "client_to_provider",
        "provider_to_client",
        "provider_stderr",
      ]),
    );
    expect(
      traceFrames.some((entry) => entry.nativeMethod === "SSE /event"),
    ).toBe(true);
    expect(
      traceEntries.some(
        (entry) =>
          entry.stage === "typescript_opencode_driver_normalization" &&
          Array.isArray(entry.emittedEventIds) &&
          entry.emittedEventIds.length > 0,
      ),
    ).toBe(true);
    expect(traceEntries.at(-1)).toMatchObject({
      kind: "trace_status",
      debugChannel: "typescript_opencode_native",
      status: "complete",
    });

    const environment = JSON.parse(
      await readFile(
        join(sessionRoot, "data", "fake-environment.json"),
        "utf8",
      ),
    );
    const mcpEvidence = JSON.parse(
      await readFile(
        join(sessionRoot, "data", "fake-mcp-evidence.json"),
        "utf8",
      ),
    );
    expect(environment.keys).toContain("OPENROUTER_API_KEY");
    expect(environment.keys).not.toContain("PAPERCLIP_API_KEY");
    expect(environment.keys).not.toContain("UNRELATED_SECRET");
    expect(environment.keys).not.toContain("PAPERCLIP_PROVIDER_TRACE_PATH");
    expect(environment.projectConfigDisabled).toBe("true");
    expect(environment.modelsFetchDisabled).toBe("true");
    expect(environment.defaultPluginsDisabled).toBe("true");
    expect(mcpEvidence.tools).toEqual(
      expect.arrayContaining(["paperclip_finish", "paperclip_block"]),
    );
    expect(config).toContain("openrouter/deepseek/deepseek-v4-flash-0731");
    expect(config).toContain('"*": "allow"');
    expect(JSON.parse(config).permission.external_directory).toMatchObject({ "*": "deny", [`${workspace}/**`]: "allow" });
    expect(
      events.some((event) => event.eventType === "runtime_request.created"),
    ).toBe(false);
    expect(config).not.toContain("test-openrouter-key");
    expect(diagnostics.join("\n")).not.toContain("test-openrouter-key");
    expect(diagnostics.join("\n")).toContain("[REDACTED]");
  });

  it.each(["role-first", "role-last", "role-last-long"])("preserves incremental text and completion with identity checks (%s)", async (roleOrder) => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-stream-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-stream-workspace-"));
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: { PATH: process.env.PATH },
    });
    const session = await driver.openSession({ runId: "stream", normalizedSessionId: "stream", workingDirectory: workspace });
    try {
      await session.startTurn({ message: { role: "user", text: `incremental-stream ${roleOrder}` } });
      const deltas: string[] = [];
      const reasoning: string[] = [];
      const events: PrpEvent[] = [];
      for await (const event of session.events()) {
        events.push(event);
        if (event.eventType === "item.delta" && event.payload.kind === "reasoning") reasoning.push(String(event.payload.text));
        if (event.eventType === "item.delta" && event.payload.kind === "agentMessage") {
          deltas.push(String(event.payload.text));
          // The fixture cannot finish its turn until a chunk reaches us.
          if (deltas.length === 1) {
            expect(await readFile(join(root, "stream", "data", "stream-released"), "utf8").catch(() => null)).toBeNull();
          }
          await writeFile(join(root, "stream", "data", "release-stream"), "ready");
        }
        if (TURN_TERMINAL_EVENT_TYPES.has(event.eventType)) break;
      }
      const expectedText = `Hi ${"👋".repeat(roleOrder === "role-last-long" ? 120 : 2)}`;
      expect(deltas).toEqual(roleOrder === "role-first" ? ["Hi ", "👋", "👋"] : [expectedText]);
      expect(reasoning).toEqual(["Thinking"]);
      expect(events.filter(event => event.eventType === "item.completed" && event.payload.kind === "agentMessage")
        .map(event => event.payload.text)).toEqual([expectedText]);
    } finally {
      await session.close({ reason: "stream test complete" });
    }
  });

  it("maps OpenCode's normal abort error to cancellation without a false provider failure notice", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-abort-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-abort-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-aborted",
      normalizedSessionId: "aborted",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "session-aborted" },
    });
    const events = await collectTurnEvents(session.events());
    expect(events.map((event) => event.eventType)).toContain("turn.cancelled");
    expect(events.map((event) => event.eventType)).not.toContain("turn.failed");
    expect(events.map((event) => event.eventType)).not.toContain(
      "provider.notice.recorded",
    );
    await session.close({ reason: "test" });
  });

  it("runs two consecutive turns on one session and delivers exactly one terminal event per turn", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-multi-turn-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-multi-turn-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-multi-turn",
      normalizedSessionId: "multi-turn",
      workingDirectory: workspace,
    });

    const firstTurn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    const firstTurnEvents = await collectTurnEvents(session.events());
    expect(
      firstTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: firstTurn.turnId }]);
    expect(
      firstTurnEvents.find(
        (event) =>
          event.eventType === "item.completed" &&
          event.payload.kind === "agentMessage",
      )?.payload,
    ).toMatchObject({ text: "done [guide](guide.md)" });

    const secondTurn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    expect(secondTurn.turnId).not.toBe(firstTurn.turnId);
    const secondTurnEvents = await collectTurnEvents(session.events());
    expect(
      secondTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: secondTurn.turnId }]);
    expect(
      secondTurnEvents.find(
        (event) =>
          event.eventType === "item.completed" &&
          event.payload.kind === "agentMessage",
      )?.payload,
    ).toMatchObject({ text: "done [guide](guide.md)" });
    expect(
      secondTurnEvents.some((event) => event.turnId === firstTurn.turnId),
    ).toBe(false);
    expect(
      secondTurnEvents.some((event) => event.eventType === "harness.diagnostic"),
    ).toBe(false);

    await session.close({ reason: "test" });
  });

  it("drops a distinct late frame for a completed turn instead of attributing it to the next turn", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-late-frame-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-late-frame-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-late-frame",
      normalizedSessionId: "late-frame",
      workingDirectory: workspace,
    });

    const firstTurn = await session.startTurn({
      message: { role: "user", text: "late-straggler-source" },
    });
    const firstTurnEvents = await collectTurnEvents(session.events());
    expect(
      firstTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: firstTurn.turnId }]);

    // The fixture holds a distinct frame for the first turn's message and
    // delivers it only once this second turn's prompt has been accepted,
    // simulating a provider frame that arrives after its own turn is
    // already sealed.
    const secondTurn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    expect(secondTurn.turnId).not.toBe(firstTurn.turnId);
    const secondTurnEvents = await collectTurnEvents(session.events());

    expect(
      secondTurnEvents.some((event) =>
        JSON.stringify(event.payload).includes(
          "late straggler text must not reach the next turn",
        ),
      ),
    ).toBe(false);
    expect(
      secondTurnEvents.some((event) => event.turnId === firstTurn.turnId),
    ).toBe(false);
    expect(
      secondTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: secondTurn.turnId }]);
    expect(
      secondTurnEvents.find(
        (event) => event.eventType === "harness.diagnostic",
      )?.payload,
    ).toMatchObject({
      code: "opencode_late_terminal_turn_event_dropped",
      turnId: firstTurn.turnId,
    });

    await session.close({ reason: "test" });
  });

  it("keeps rejecting a late frame for a sealed turn no matter how many later turns have already sealed", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-sealed-many-turns-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-sealed-many-turns-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-sealed-many-turns",
      normalizedSessionId: "sealed-many-turns",
      workingDirectory: workspace,
    });

    // Turn A schedules its own late frame to arrive four prompts later, so
    // it lands only after three more turns have sealed. The late-frame gate
    // in `#emit` compares directly against the current active turn, not a
    // bounded history, so it must still reject this frame no matter how
    // many turns sealed in between.
    const turnA = await session.startTurn({
      message: { role: "user", text: "late-straggler-source-delay-4" },
    });
    await collectTurnEvents(session.events());

    for (let index = 0; index < 3; index += 1) {
      await session.startTurn({ message: { role: "user", text: "finish" } });
      await collectTurnEvents(session.events());
    }

    // This turn's prompt request is what finally delivers turn A's scheduled
    // late frame, well after turn A's own turn sealed.
    const turnE = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    const turnEEvents = await collectTurnEvents(session.events());

    expect(
      turnEEvents.some((event) =>
        JSON.stringify(event.payload).includes(
          "late straggler text must not reach the next turn",
        ),
      ),
    ).toBe(false);
    expect(turnEEvents.some((event) => event.turnId === turnA.turnId)).toBe(
      false,
    );
    expect(
      turnEEvents.find((event) => event.eventType === "harness.diagnostic")
        ?.payload,
    ).toMatchObject({
      code: "opencode_late_terminal_turn_event_dropped",
      turnId: turnA.turnId,
    });
    expect(
      turnEEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: turnE.turnId }]);

    await session.close({ reason: "test" });
  });

  it("delivers the settlement event for a runtime request whose turn fails through the same single-pass consumer that reads the turn", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-pending-then-fail-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-pending-then-fail-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-pending-then-fail",
      normalizedSessionId: "pending-then-fail",
      workingDirectory: workspace,
    });

    const { turnId } = await session.startTurn({
      message: { role: "user", text: "pending-request-then-turn-fails" },
    });
    // The fixture asks a native question, which leaves a runtime request
    // pending, then fails the same turn through `session.error` without
    // ever resolving that request. `collectTurnEvents` reads exactly one
    // pass and stops at the turn's terminal event, the same rule the
    // production consumer applies (see its doc comment above). The
    // settlement event must arrive inside that same pass: a production
    // consumer that stops at `turn.failed` never opens a second read
    // afterward, so a settlement event that only `close()` produced later
    // would never reach it.
    const turnEvents = await collectTurnEvents(session.events());
    expect(
      turnEvents.some(
        (event) => event.eventType === "runtime_request.created",
      ),
    ).toBe(true);
    const settlementIndex = turnEvents.findIndex(
      (event) => event.eventType === "runtime_request.expired",
    );
    const terminalIndex = turnEvents.findIndex(
      (event) => event.eventType === "turn.failed",
    );
    expect(settlementIndex).toBeGreaterThanOrEqual(0);
    expect(terminalIndex).toBeGreaterThanOrEqual(0);
    // The settlement fact must precede the turn's terminal event, or a
    // consumer that stops reading at that terminal event misses it.
    expect(settlementIndex).toBeLessThan(terminalIndex);
    expect(turnEvents[settlementIndex]).toMatchObject({
      turnId,
      itemId: "question-native-1",
    });
    expect(turnEvents[terminalIndex]).toMatchObject({ turnId });
    expect(
      turnEvents.some(
        (event) =>
          event.eventType === "harness.diagnostic" &&
          event.payload.code === "opencode_late_terminal_turn_event_dropped" &&
          event.payload.turnId === turnId,
      ),
    ).toBe(false);
    // The request already settled with the turn; nothing is left pending
    // for `close()` to settle a second time.
    expect(session.pendingRuntimeRequests?.()).toHaveLength(0);

    await session.close({ reason: "test" });
    const closeEvents = await collectTurnEvents(session.events());
    expect(
      closeEvents.some((event) =>
        ["runtime_request.expired", "runtime_request.cancelled"].includes(
          event.eventType,
        ),
      ),
    ).toBe(false);
  });

  it("keeps the session usable after a cancelled turn so the next turn on the same session still completes", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-cancel-then-finish-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-cancel-then-finish-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-cancel-then-finish",
      normalizedSessionId: "cancel-then-finish",
      workingDirectory: workspace,
    });

    const cancelledTurn = await session.startTurn({
      message: { role: "user", text: "session-aborted" },
    });
    const cancelledTurnEvents = await collectTurnEvents(session.events());
    expect(
      cancelledTurnEvents.filter(
        (event) => event.eventType === "turn.cancelled",
      ),
    ).toMatchObject([{ turnId: cancelledTurn.turnId }]);

    const secondTurn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    const secondTurnEvents = await collectTurnEvents(session.events());
    expect(
      secondTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: secondTurn.turnId }]);
    expect(
      secondTurnEvents.some((event) => event.turnId === cancelledTurn.turnId),
    ).toBe(false);

    await session.close({ reason: "test" });
  });

  it("keeps the session usable after a failed turn so the next turn on the same session still completes", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-fail-then-finish-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-fail-then-finish-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-fail-then-finish",
      normalizedSessionId: "fail-then-finish",
      workingDirectory: workspace,
    });

    const failedTurn = await session.startTurn({
      message: { role: "user", text: "session-failed" },
    });
    const failedTurnEvents = await collectTurnEvents(session.events());
    expect(
      failedTurnEvents.filter((event) => event.eventType === "turn.failed"),
    ).toMatchObject([{ turnId: failedTurn.turnId }]);

    const secondTurn = await session.startTurn({
      message: { role: "user", text: "finish" },
    });
    const secondTurnEvents = await collectTurnEvents(session.events());
    expect(
      secondTurnEvents.filter((event) => event.eventType === "turn.completed"),
    ).toMatchObject([{ turnId: secondTurn.turnId }]);
    expect(
      secondTurnEvents.some((event) => event.turnId === failedTurn.turnId),
    ).toBe(false);

    await session.close({ reason: "test" });
  });

  it("still ends the event stream once the session closes", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-close-ends-stream-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-close-ends-stream-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-close-ends-stream",
      normalizedSessionId: "close-ends-stream",
      workingDirectory: workspace,
    });

    await session.startTurn({ message: { role: "user", text: "finish" } });
    await collectTurnEvents(session.events());
    await session.close({ reason: "test" });

    const eventsAfterClose: PrpEvent[] = [];
    for await (const event of session.events()) eventsAfterClose.push(event);
    expect(eventsAfterClose).toEqual([]);
  });

  it("keeps OpenCode in an outer supervisor process group when requested", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    let processGroupId: number | null | undefined;
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
      isolateProcessGroup: false,
      onSpawn: async (meta) => {
        processGroupId = meta.processGroupId;
      },
    });
    const session = await driver.openSession({
      runId: "run-supervised",
      normalizedSessionId: "supervised",
      workingDirectory: workspace,
    });
    expect(processGroupId).toBeNull();
    await session.close({ reason: "test" });
  });

  it.each([false, true])("uses the native system channel, selected skill tree, instruction root, and assigned MCP gateway after startup retry=%s", async (retryStartup) => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-context-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-context-workspace-"),
    );
    const skillRoot = join(root, "skill-source");
    const instructionRoot = join(root, "instruction-source");
    roots.push(root, workspace);
    await Promise.all([
      mkdir(join(skillRoot, "references"), { recursive: true }),
      mkdir(instructionRoot, { recursive: true }),
    ]);
    await Promise.all([
      writeFile(
        join(skillRoot, "SKILL.md"),
        "# Assigned\nRead references/support.md\n",
      ),
      writeFile(join(skillRoot, "references", "support.md"), "skill support\n"),
      writeFile(join(instructionRoot, "AGENTS.md"), "Read sibling.md\n"),
      writeFile(join(instructionRoot, "sibling.md"), "instruction sibling\n"),
    ]);
    const systemInstructions = `${PAPERCLIP_EXECUTION_PROMPT}\n\nRead sibling.md\n\nRead-only instruction sibling root: ${instructionRoot}`;
    let submittedPrompt: Record<string, unknown> | null = null;
    let startupFailurePending = retryStartup;
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      systemInstructions,
      runtimeContext: runtimeContext(skillRoot, instructionRoot),
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
        PAPERCLIP_NATIVE_MCP_NAME: "paperclip-assigned",
        PAPERCLIP_NATIVE_MCP_URL: "https://paperclip.example/mcp",
        PAPERCLIP_NATIVE_MCP_TOKEN: "x".repeat(40),
      },
      fetch: async (input, init) => {
        if (startupFailurePending && String(input).endsWith("/session") && init?.method === "POST") {
          startupFailurePending = false;
          return new Response("Fixture startup failure", { status: 503 });
        }
        if (String(input).endsWith("/prompt_async"))
          submittedPrompt = JSON.parse(String(init?.body));
        return fetch(input, init);
      },
    });
    const session = await driver.openSession({
      runId: "run-context",
      normalizedSessionId: "context",
      workingDirectory: workspace,
    });
    await session.startTurn({ message: { role: "user", text: "finish" } });
    for await (const event of session.events()) {
      if (event.eventType === "turn.completed") break;
    }
    expect(submittedPrompt).toMatchObject({
      system: systemInstructions,
    });
    // A prompt tools map replaces OpenCode's session permissions. Question is
    // enabled in config without overwriting the allow/ask/deny or path policy.
    expect(submittedPrompt).not.toHaveProperty("tools");
    expect(JSON.stringify(submittedPrompt?.parts ?? null)).not.toContain(
      PAPERCLIP_EXECUTION_PROMPT,
    );
    const sessionRoot = join(root, "context");
    const runtimeEnvironment = JSON.parse(
      await readFile(join(sessionRoot, "data", "fake-environment.json"), "utf8"),
    );
    const isolatedHome = runtimeEnvironment.home;
    expect(startupFailurePending).toBe(false);
    expect(dirname(isolatedHome)).toBe(join(sessionRoot, "homes"));
    expect(basename(isolatedHome)).toMatch(/^home-/);
    await expect(
      readFile(
        join(
          isolatedHome,
          ".claude",
          "skills",
          "assigned",
          "references",
          "support.md",
        ),
        "utf8",
      ),
    ).resolves.toBe("skill support\n");
    const config = JSON.parse(
      await readFile(
        join(sessionRoot, "config", "opencode", "opencode.json"),
        "utf8",
      ),
    );
    expect(config).toMatchObject({
      instructions: [],
      plugin: [],
      tools: { question: true },
      permission: {
        external_directory: { "*": "deny", [`${instructionRoot}/**`]: "allow" },
      },
      mcp: {
        paperclip: { enabled: true },
        "paperclip-assigned": {
          url: "https://paperclip.example/mcp",
          enabled: true,
        },
      },
    });
    await expect(
      readFile(join(instructionRoot, "sibling.md"), "utf8"),
    ).resolves.toBe("instruction sibling\n");
    await session.close({ reason: "test" });
    await expect(readdir(join(sessionRoot, "homes"))).resolves.toEqual([]);
  });

  it("removes isolated homes left by earlier launches when a session reopens", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-legacy-home-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-legacy-home-workspace-"),
    );
    const skillRoot = join(root, "skill-source");
    const instructionRoot = join(root, "instruction-source");
    roots.push(root, workspace);
    await Promise.all([
      mkdir(skillRoot, { recursive: true }),
      mkdir(instructionRoot, { recursive: true }),
    ]);
    await writeFile(join(skillRoot, "SKILL.md"), "# Assigned\n");
    await writeFile(join(instructionRoot, "AGENTS.md"), "instructions\n");
    const sessionRoot = join(root, "legacy");
    const legacyHome = join(sessionRoot, "home-AbC123");
    const sealedSkill = join(legacyHome, ".claude", "skills", "assigned");
    await mkdir(sealedSkill, { recursive: true });
    await mkdir(join(legacyHome, ".npm", "_cacache"), { recursive: true });
    await writeFile(join(legacyHome, ".npm", "_cacache", "entry"), "cache");
    await writeFile(join(sealedSkill, "SKILL.md"), "# Assigned\n");
    await chmod(join(sealedSkill, "SKILL.md"), 0o444);
    await chmod(sealedSkill, 0o555);
    await mkdir(join(sessionRoot, "data", "opencode"), { recursive: true });
    await writeFile(join(sessionRoot, "data", "opencode", "opencode.db"), "history");
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      runtimeContext: runtimeContext(skillRoot, instructionRoot),
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-legacy-home",
      normalizedSessionId: "legacy",
      workingDirectory: workspace,
    });
    await expect(lstat(legacyHome)).rejects.toMatchObject({ code: "ENOENT" });
    await session.close({ reason: "test" });
    expect(
      (await readdir(sessionRoot)).filter((entry) => entry.startsWith("home-")),
    ).toEqual([]);
    await expect(readdir(join(sessionRoot, "homes"))).resolves.toEqual([]);
    await expect(
      readFile(join(sessionRoot, "data", "opencode", "opencode.db"), "utf8"),
    ).resolves.toBe("history");
  });

  it("resends system instructions without repeating the task envelope on recovery", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-resume-context-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-resume-workspace-"),
    );
    roots.push(root, workspace);
    let submittedPrompt: Record<string, unknown> | null = null;
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      systemInstructions: "large original system context",
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
      fetch: async (input, init) => {
        if (String(input).endsWith("/prompt_async"))
          submittedPrompt = JSON.parse(String(init?.body));
        return fetch(input, init);
      },
    });
    const seed = await driver.openSession({
      runId: "run-seed",
      normalizedSessionId: "resume-context",
      workingDirectory: workspace,
    });
    const snapshot = await seed.snapshot();
    await seed.close({ reason: "seed complete" });

    const recovered = await driver.recoverSession?.(snapshot);
    expect(recovered).toMatchObject({ recovered: true });
    await recovered!.session!.startTurn({
      message: {
        role: "user",
        text: '{"interactionResponses":[{"answer":"friendly"}]}',
      },
    });
    for await (const event of recovered!.session!.events()) {
      if (event.eventType === "turn.completed") break;
    }

    expect(submittedPrompt).toMatchObject({
      providerID: "openrouter",
      modelID: "deepseek/deepseek-v4-flash-0731",
      parts: [
        {
          type: "text",
          text: '{"interactionResponses":[{"answer":"friendly"}]}',
        },
      ],
    });
    expect(submittedPrompt).not.toHaveProperty("tools");
    expect(submittedPrompt).toHaveProperty("system", "large original system context");
    await recovered!.session!.close({ reason: "recovery-test" });
  });

  it("normalizes native question.asked events and replies with ordered OpenCode answer arrays", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-question-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-question-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-native-question",
      normalizedSessionId: "native-question",
      workingDirectory: workspace,
    });
    const { turnId } = await session.startTurn({
      message: { role: "user", text: "native-question" },
    });
    const iterator = session.events()[Symbol.asyncIterator]();
    let requestEvent:
      Awaited<ReturnType<typeof iterator.next>>["value"] | null = null;
    for (let count = 0; count < 30; count += 1) {
      const event = await iterator.next();
      if (event.done) break;
      if (event.value.eventType === "runtime_request.created") {
        requestEvent = event.value;
        break;
      }
    }
    expect(requestEvent?.payload).toMatchObject({
      request: {
        schema: "paperclip.runtime_request.v2",
        requestKind: "runtime",
        type: "input",
        input: {
          schema: "paperclip.question_set.v1",
          questions: [
            {
              id: "environment",
              answerMode: "single_select",
              required: false,
              customAnswer: { enabled: true },
            },
            { id: "regions", answerMode: "multi_select", required: false },
          ],
        },
      },
    });
    await new Promise((resolveDelay) => setTimeout(resolveDelay, 20));
    expect(session.pendingRuntimeRequests?.()).toHaveLength(1);
    await session.resolveRuntimeRequest?.({
      requestId: "question-native-1",
      turnId,
      resolution: {
        action: "submit",
        response: {
          schema: "paperclip.question_response.v1",
          answers: {
            environment: { customText: "Canary" },
            regions: { selectedOptionIds: ["option-1", "option-2"] },
          },
        },
      },
    });
    const reply = JSON.parse(
      await readFile(
        join(root, "native-question", "data", "fake-question-reply.json"),
        "utf8",
      ),
    );
    expect(reply).toEqual({
      url: expect.stringContaining(
        `directory=${encodeURIComponent(workspace)}`,
      ),
      body: { answers: [["Canary"], ["US", "EU"]] },
    });
    const terminalQuestionEvents =
      (await session.transcript?.())?.events.filter(
        (event) =>
          event.payload.requestId === "question-native-1" &&
          ["runtime_request.resolved", "runtime_request.cancelled"].includes(
            event.eventType,
          ),
      ) ?? [];
    expect(terminalQuestionEvents).toHaveLength(1);
    expect(terminalQuestionEvents[0]?.payload).toMatchObject({
      action: "submit",
      response: {
        schema: "paperclip.question_response.v1",
        answers: {
          environment: { customText: "Canary" },
          regions: { selectedOptionIds: ["option-1", "option-2"] },
        },
      },
    });
    await session.close({ reason: "test" });
  });

  it("hands a native question to the durable interaction path without touching permissions", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-question-handoff-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-question-handoff-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-native-question-handoff",
      normalizedSessionId: "native-question-handoff",
      workingDirectory: workspace,
    });
    const { turnId } = await session.startTurn({
      message: { role: "user", text: "native-question" },
    });
    const iterator = session.events()[Symbol.asyncIterator]();
    let created: Awaited<ReturnType<typeof iterator.next>>["value"] | null =
      null;
    for (let count = 0; count < 30; count += 1) {
      const next = await iterator.next();
      if (next.done) break;
      if (next.value.eventType === "runtime_request.created") {
        created = next.value;
        break;
      }
    }
    expect(created).toMatchObject({
      payload: { request: { requestId: "question-native-1", type: "input" } },
    });

    const firstHandoff = session.handoffRuntimeRequest?.({
      requestId: "question-native-1",
      turnId,
      reason: "durable_handoff",
      signal: new AbortController().signal,
    });
    expect(firstHandoff?.result).toBe("handed_off");
    await firstHandoff?.cleanup;
    const repeatedHandoff = session.handoffRuntimeRequest?.({
      requestId: "question-native-1",
      turnId,
      reason: "durable_handoff",
      signal: new AbortController().signal,
    });
    expect(repeatedHandoff?.result).toBe("already_settled");
    await repeatedHandoff?.cleanup;

    let expired: Awaited<ReturnType<typeof iterator.next>>["value"] | null =
      null;
    for (let count = 0; count < 20; count += 1) {
      const next = await iterator.next();
      if (next.done) break;
      if (next.value.eventType === "runtime_request.expired") {
        expired = next.value;
        break;
      }
    }
    expect(expired).toMatchObject({
      payload: {
        requestId: "question-native-1",
        reason: "durable_handoff",
        replayAllowed: false,
        requestType: "input",
        request: {
          schema: "paperclip.runtime_request.v2",
          requestId: "question-native-1",
          type: "input",
        },
      },
    });
    expect(session.pendingRuntimeRequests?.()).toEqual([]);
    const terminal = (await session.transcript?.())?.events.filter(
      (event) =>
        event.payload.requestId === "question-native-1" &&
        [
          "runtime_request.resolved",
          "runtime_request.cancelled",
          "runtime_request.expired",
        ].includes(event.eventType),
    );
    expect(terminal).toHaveLength(1);
    await session.close({ reason: "handoff test complete" });
  });

  it("recovers a missed pending question from the list endpoint and rejects it", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-question-recovery-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-question-recovery-workspace-"),
    );
    roots.push(root, workspace);
    const normalizedSessionId = "question-recovery";
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const seed = await driver.openSession({
      runId: "run-question-recovery",
      normalizedSessionId,
      workingDirectory: workspace,
    });
    const snapshot = await seed.snapshot();
    await seed.close({ reason: "simulate reconnect" });
    const dataRoot = join(root, normalizedSessionId, "data");
    await mkdir(dataRoot, { recursive: true });
    await writeFile(
      join(dataRoot, "fake-pending-question.json"),
      JSON.stringify({
        id: "question-native-1",
        sessionID: "ses_fake_1",
        questions: [
          {
            id: "environment",
            header: "Environment",
            question: "Where should we deploy?",
            options: [{ label: "Staging" }, { label: "Production" }],
            custom: true,
          },
        ],
      }),
    );

    const recovered = await driver.recoverSession?.({
      ...snapshot,
      activeTurnId: "turn-recovered-question",
    });
    expect(recovered).toMatchObject({ recovered: true });
    const session = recovered!.session!;
    const iterator = session.events()[Symbol.asyncIterator]();
    let created: Awaited<ReturnType<typeof iterator.next>>["value"] | null =
      null;
    for (let count = 0; count < 20; count += 1) {
      const next = await iterator.next();
      if (next.done) break;
      if (next.value.eventType === "runtime_request.created") {
        created = next.value;
        break;
      }
    }
    expect(created).toMatchObject({
      payload: { request: { requestId: "question-native-1", type: "input" } },
    });
    await session.resolveRuntimeRequest?.({
      requestId: "question-native-1",
      turnId: "turn-recovered-question",
      resolution: { action: "decline" },
    });
    expect(session.pendingRuntimeRequests?.()).toEqual([]);
    await session.close({ reason: "recovery test complete" });
  });

  it.each([
    { style: "legacy", action: "accept" as const, reply: "once" },
    { style: "v2", action: "accept_for_session" as const, reply: "always" },
    { style: "v2", action: "decline" as const, reply: "reject" },
  ])(
    "normalizes $style permission events and maps $action to $reply",
    async ({ style, action, reply }) => {
      await chmod(fixture, 0o755);
      const root = await mkdtemp(
        join(tmpdir(), `paperclip-opencode-permission-${style}-`),
      );
      const workspace = await mkdtemp(
        join(tmpdir(), `paperclip-opencode-permission-${style}-workspace-`),
      );
      roots.push(root, workspace);
      const driver = new OpenCodeServerDriver({
        model: "openrouter/deepseek/deepseek-v4-flash-0731",
        permissionMode: "ask",
        runtimeDirectory: root,
        command: fixture,
        environment: {
          PATH: process.env.PATH,
          OPENROUTER_API_KEY: "fixture-key",
        },
      });
      const normalizedSessionId = `native-permission-${style}-${action}`;
      const session = await driver.openSession({
        runId: `run-${normalizedSessionId}`,
        normalizedSessionId,
        workingDirectory: workspace,
      });
      const { turnId } = await session.startTurn({
        message: { role: "user", text: `native-permission-${style}` },
      });
      const iterator = session.events()[Symbol.asyncIterator]();
      let created: Awaited<ReturnType<typeof iterator.next>>["value"] | null =
        null;
      for (let count = 0; count < 30; count += 1) {
        const next = await iterator.next();
        if (next.done) break;
        if (next.value.eventType === "runtime_request.created") {
          created = next.value;
          break;
        }
      }
      expect(created).toMatchObject({
        payload: {
          request: {
            requestId: "permission-native-1",
            type: "permission",
            actions: ["accept", "accept_for_session", "decline", "cancel"],
          },
        },
      });
      await session.resolveRuntimeRequest?.({
        requestId: "permission-native-1",
        turnId,
        resolution: { action },
      });
      const persisted = JSON.parse(
        await readFile(
          join(root, normalizedSessionId, "data", "fake-permission-reply.json"),
          "utf8",
        ),
      );
      expect(persisted).toEqual({
        url: expect.stringContaining(
          `directory=${encodeURIComponent(workspace)}`,
        ),
        body: { reply },
      });
      expect(session.pendingRuntimeRequests?.()).toEqual([]);
      await session.close({ reason: "permission test complete" });
    },
  );

  it.each(["allow", "ask", "deny"] as const)(
    "pins the %s permission mode while retaining external-directory denial",
    async (permissionMode) => {
      await chmod(fixture, 0o755);
      const root = await mkdtemp(
        join(tmpdir(), `paperclip-opencode-mode-${permissionMode}-`),
      );
      const workspace = await mkdtemp(
        join(tmpdir(), `paperclip-opencode-mode-${permissionMode}-workspace-`),
      );
      roots.push(root, workspace);
      const driver = new OpenCodeServerDriver({
        model: "openrouter/deepseek/deepseek-v4-flash-0731",
        permissionMode,
        runtimeDirectory: root,
        command: fixture,
        environment: {
          PATH: process.env.PATH,
          OPENROUTER_API_KEY: "fixture-key",
        },
      });
      const session = await driver.openSession({
        runId: `run-${permissionMode}`,
        normalizedSessionId: permissionMode,
        workingDirectory: workspace,
      });
      const config = JSON.parse(
        await readFile(
          join(root, permissionMode, "config", "opencode", "opencode.json"),
          "utf8",
        ),
      );
      expect(config.permission).toMatchObject({
        "*": permissionMode,
        external_directory: { "*": "deny", [`${workspace}/**`]: "allow" },
      });
      expect(config.autoupdate).toBe(false);
      expect(config.provider.openrouter.options.headers).toMatchObject({
        "HTTP-Referer": "https://paperclip.ing", "X-Title": "Paperclip", "X-OpenRouter-Title": "Paperclip",
      });
      expect(config.provider.openrouter.models).toHaveProperty(
        "deepseek/deepseek-v4-flash-0731",
      );
      expect(config.provider.openrouter.models["deepseek/deepseek-v4-flash-0731"].options).toBeUndefined();
      expect(config.permission.paperclip_finish).toBeUndefined();
      expect(config.permission["paperclip_*"]).toBe("allow");
      await session.close({ reason: "permission mode test complete" });
    },
  );

  it.skipIf(process.platform === "win32")("allows the selected workspace alias and its canonical path while denying other directories", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-workspace-alias-"));
    roots.push(root);
    const workspace = join(root, "actual-workspace");
    const alias = join(root, "workspace-alias");
    await mkdir(workspace);
    await symlink(workspace, alias, "dir");
    const canonical = await realpath(workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      permissionMode: "allow",
      runtimeDirectory: root,
      command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
    });
    const session = await driver.openSession({
      runId: "run-workspace-alias", normalizedSessionId: "alias-session",
      workingDirectory: alias,
    });
    try {
      const config = JSON.parse(await readFile(join(root, "alias-session", "config", "opencode", "opencode.json"), "utf8"));
      expect(config.permission.external_directory).toEqual({
        "*": "deny", [alias]: "allow", [`${alias}/**`]: "allow",
        [canonical]: "allow", [`${canonical}/**`]: "allow",
      });
    } finally { await session.close({ reason: "workspace alias test complete" }); }
  });

  it("clears a stale active turn that already has a persisted terminal fingerprint", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-stale-turn-"),
    );
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-stale-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const seed = await driver.openSession({
      runId: "run-stale-turn",
      normalizedSessionId: "stale-turn",
      workingDirectory: workspace,
    });
    const snapshot = await seed.snapshot();
    await seed.close({ reason: "seed complete" });

    const recoveryDriver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const recovery = await recoveryDriver.recoverSession?.({
      ...snapshot,
      activeTurnId: "turn-already-terminal",
      terminalTurns: [
        {
          turnId: "turn-already-terminal",
          fingerprint: "terminal-fingerprint",
        },
      ],
    });
    expect(recovery).toMatchObject({ recovered: true });
    await expect(recovery!.session!.snapshot()).resolves.toMatchObject({
      activeTurnId: null,
    });
    await recovery!.session!.close({ reason: "recovery-test" });
  });

  it("validates provider/model form", async () => {
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    roots.push(root);
    const driver = new OpenCodeServerDriver({
      model: "bad",
      runtimeDirectory: root,
    });
    await expect(
      driver.validateConfig?.({ model: "bad" }),
    ).resolves.toMatchObject({ ok: false });
    await expect(
      driver.validateConfig?.({ model: "openrouter/model" }),
    ).resolves.toMatchObject({ ok: true });
  });

  it.each(["wrong", "missing", "duplicate"])("returns a repairable tool error for %s criteria without committing a bad semantic result", async (mode) => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-criteria-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-workspace-"));
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({ model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture, environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" }, taskEnvelope: createCodexTaskEnvelope({ objective: "Apply the accepted decision", contractRevision: "approval-v2", criteria: [{ id: "human_response", requirement: "Apply the approved response" }] }) });
    const session = await driver.openSession({ runId: "criteria-repair", normalizedSessionId: "criteria-repair", workingDirectory: workspace });
    await session.startTurn({ message: { role: "user", text: `repair-criteria-${mode}` } });
    const events = await collectTurnEvents(session.events());
    const results = events.filter((event) => event.eventType === "run.result.proposed");
    expect(results).toHaveLength(1);
    expect(events.some((event) => event.eventType === "item.completed" &&
      (event.payload as { item?: { is_error?: boolean } }).item?.is_error === true)).toBe(true);
    expect(results[0].payload).toMatchObject({ completionClaim: { criteria: [{ criterionId: "human_response" }] } });
    const files = await readdir(root, { recursive: true });
    const evidence = files.find((name) => name.endsWith("fake-criteria-repair.json"));
    expect(evidence).toBeDefined();
    expect(JSON.parse(await readFile(join(root, evidence!), "utf8"))).toMatchObject({ result: { isError: true, content: [{ text: expect.stringContaining('"human_response"') }] } });
    await session.close({ reason: "test" });
  });

  it.each([true, false])("resolves an omitted continuation through the real OpenCode MCP boundary only with a saved monitor: %s", async eligible => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-monitor-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-monitor-workspace-"));
    roots.push(root, workspace);
    const continuation = { kind: "monitor", summary: "Wait for the saved task monitor.", idempotencyKey: "task-monitor:saved" };
    const reads: string[] = [];
    const accepted: unknown[] = [];
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      dynamicToolHandler: async call => {
        reads.push(call.tool);
        return { run: { id: "monitor-default" }, activeTask: { executionRunId: "monitor-default" },
          completionContinuation: eligible ? continuation : null };
      },
      completionFeedback: async result => { accepted.push(result); return "Accepted monitor wait."; },
    });
    const session = await driver.openSession({ runId: "monitor-default", normalizedSessionId: "monitor-default", workingDirectory: workspace });
    try {
      await session.startTurn({ message: { role: "user", text: "monitor-default" } });
      const events = await collectTurnEvents(session.events());
      expect(reads).toEqual(["get_task_context"]);
      if (eligible) {
        expect(accepted).toMatchObject([{ reportedWorkDisposition: "yielded", continuation }]);
        expect(events.filter(event => event.eventType === "run.result.proposed")).toHaveLength(1);
        expect((await session.snapshot()).semanticResult?.result).toMatchObject({ continuation });
      } else {
        expect(accepted).toEqual([]);
        expect(events.filter(event => event.eventType === "run.result.proposed")).toEqual([]);
        expect((await session.snapshot()).semanticResult).toBeNull();
      }
    } finally { await session.close({ reason: "monitor default test complete" }); }
  });

  it("keeps assigned discovery operation IDs at the authenticated MCP and controller boundary", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-assigned-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-workspace-"));
    roots.push(root, workspace);
    const calls: string[] = [];
    const operation = "paperclip_search_assigned_tools";
    const driver = new OpenCodeServerDriver({ model: "openrouter/deepseek/deepseek-v4.1-flash-1017", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      dynamicTools: [{ name: operation, inputSchema: { type: "object" } }],
      dynamicToolHandler: async call => { calls.push(call.tool); if (call.tool !== operation) throw new Error("unauthorized operation"); return { tools: [] }; },
    });
    const session = await driver.openSession({ runId: "assigned-name", normalizedSessionId: "assigned-name", workingDirectory: workspace });
    try {
      await session.startTurn({ message: { role: "user", text: "Discover assigned tools." } });
      const events = await collectTurnEvents(session.events());
      expect(calls).toEqual([operation]);
      expect(events.some(event => event.eventType === "item.completed" && (event.payload as { item?: { is_error?: boolean } }).item?.is_error)).toBe(false);
    } finally { await session.close({ reason: "assigned operation identity test" }); }
  });

  it("normalizes a structured block result", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-block",
      normalizedSessionId: "block",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "block-result" },
    });
    const events = await collectTurnEvents(session.events());
    expect(
      events.find((event) => event.eventType === "run.result.proposed")
        ?.payload,
    ).toMatchObject({
      reportedWorkDisposition: "blocked",
      blocker: { reasonCode: "test_dependency" },
    });
    await session.close({ reason: "test" });
  });

  it("designates the substantive pre-finish response instead of a trailing acknowledgement", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-final-selection",
      normalizedSessionId: "final-selection",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "text-before-finish" },
    });
    const events = await collectTurnEvents(session.events());
    const finalMessages = events.filter(
      (event) =>
        event.eventType === "item.completed" &&
        event.payload.kind === "agentMessage" &&
        event.payload.channel === "final",
    );
    expect(finalMessages).toHaveLength(1);
    expect(finalMessages[0]?.payload.text).toBe(
      "Substantive answer before finish.",
    );
    expect(
      events
        .filter((event) => event.eventType === "item.delta")
        .map((event) => event.payload.text),
    ).toEqual(
      expect.arrayContaining(["Substantive answer before finish.", "Done."]),
    );
    await session.close({ reason: "test" });
  });

  it("does not promote opening commentary to the final response when work follows it", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-commentary-only",
      normalizedSessionId: "commentary-only",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "commentary-only-before-work" },
    });
    const events = await collectTurnEvents(session.events());
    expect(
      events.filter(
        (event) =>
          event.eventType === "item.completed" &&
          event.payload.kind === "agentMessage" &&
          event.payload.channel === "final",
      ),
    ).toHaveLength(0);
    expect(
      events
        .filter((event) => event.eventType === "item.delta")
        .map((event) => event.payload.text),
    ).toContain("I will inspect the workspace first.");
    expect(events).toContainEqual(
      expect.objectContaining({ eventType: "run.result.proposed" }),
    );
    await session.close({ reason: "test" });
  });

  it("correlates the final response to the native message containing the semantic tool", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-correlated-final-selection",
      normalizedSessionId: "correlated-final-selection",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "correlated-final-message" },
    });
    const events = await collectTurnEvents(session.events());
    const finalMessages = events.filter(
      (event) =>
        event.eventType === "item.completed" &&
        event.payload.kind === "agentMessage" &&
        event.payload.channel === "final",
    );
    expect(finalMessages).toHaveLength(1);
    expect(finalMessages[0]?.payload.text).toBe(
      "Correlated substantive final answer.",
    );
    const assistantDeltas = events.filter(
      (event) =>
        event.eventType === "item.delta" &&
        event.payload.kind === "agentMessage",
    );
    expect(assistantDeltas.map((event) => event.payload.text)).toEqual([
      "I will write the result now.",
      "Correlated substantive final answer.",
      "Done.",
    ]);
    expect(assistantDeltas).toHaveLength(3);
    expect(
      assistantDeltas.every(
        (event) =>
          event.payload.channel === "progress" &&
          event.payload.providerPhase === "commentary",
      ),
    ).toBe(true);
    expect(assistantDeltas.map((event) => event.payload.item)).toEqual([
      expect.objectContaining({
        type: "agentMessage",
        channel: "progress",
        phase: "commentary",
      }),
      expect.objectContaining({
        type: "agentMessage",
        channel: "progress",
        phase: "commentary",
      }),
      expect.objectContaining({
        type: "agentMessage",
        channel: "progress",
        phase: "commentary",
      }),
    ]);
    expect(finalMessages[0]?.itemId).toBe(
      assistantDeltas.find(
        (event) =>
          event.payload.text === "Correlated substantive final answer.",
      )?.itemId,
    );
    expect(finalMessages[0]?.payload).toMatchObject({
      kind: "agentMessage",
      channel: "final",
      providerPhase: "final_answer",
    });
    await session.close({ reason: "test" });
  });

  it("uses provider structure rather than prose length to select a post-tool answer", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
    });
    const session = await driver.openSession({
      runId: "run-post-tool-final-selection",
      normalizedSessionId: "post-tool-final-selection",
      workingDirectory: workspace,
    });
    await session.startTurn({
      message: { role: "user", text: "final-after-tool-commentary" },
    });
    const events = await collectTurnEvents(session.events());
    const finalMessages = events.filter(
      (event) =>
        event.eventType === "item.completed" &&
        event.payload.kind === "agentMessage" &&
        event.payload.channel === "final",
    );
    expect(finalMessages).toHaveLength(1);
    expect(finalMessages[0]?.payload.text).toBe(
      "This is the complete substantive answer emitted after the accepted completion tool call.",
    );
    await session.close({ reason: "test" });
  });

  it.each(["session.idle", "session.status", "session.error", "aborted"])("settles accepted completion before a racing %s event", async terminalType => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-completion-race-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-completion-race-workspace-"));
    roots.push(root, workspace);
    let stream: ReadableStreamDefaultController<Uint8Array>;
    let releaseFeedback!: () => void;
    let feedbackStarted!: () => void;
    const started = new Promise<void>(resolve => { feedbackStarted = resolve; });
    const release = new Promise<void>(resolve => { releaseFeedback = resolve; });
    const feedback = "Accepted. Keep the exact saved document link in the final response.";
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      fetch: async (input, init) => String(input).endsWith("/event")
        ? new Response(new ReadableStream<Uint8Array>({ start(controller) { stream = controller; } }), { headers: { "Content-Type": "text/event-stream" } })
        : fetch(input, init),
      completionFeedback: async () => { feedbackStarted(); await release; return feedback; },
    });
    const session = await driver.openSession({ runId: "completion-race", normalizedSessionId: "completion-race", workingDirectory: workspace });
    try {
      const events = collectTurnEvents(session.events());
      await session.startTurn({ message: { role: "user", text: "completion-feedback" } });
      await started;
      stream!.enqueue(new TextEncoder().encode(`data: ${JSON.stringify({ type: terminalType === "aborted" ? "session.error" : terminalType, id: "terminal-during-feedback", properties: { sessionID: session.ids().providerSessionId, status: { type: "idle" }, error: terminalType === "aborted" ? { name: "MessageAbortedError", data: { message: "Aborted" } } : { name: "FixtureError", message: "Provider ended during feedback." } } })}\n\n`));
      // Drain the queued SSE frame before releasing the controller response.
      await new Promise<void>(resolve => setImmediate(resolve));
      releaseFeedback();
      const observed = await events;
      const proposed = observed.findIndex(event => event.eventType === "run.result.proposed");
      const completed = observed.findIndex(event => event.eventType === "item.completed" && event.payload.kind === "dynamicToolCall" && (event.payload.item as { result?: unknown })?.result === feedback);
      const terminal = observed.findIndex(event => TURN_TERMINAL_EVENT_TYPES.has(event.eventType));
      expect(proposed).toBeGreaterThanOrEqual(0);
      expect(completed).toBeGreaterThan(proposed);
      expect(terminal).toBeGreaterThan(completed);
      expect(observed.filter(event => event.eventType === "run.result.proposed")).toHaveLength(1);
      expect((await session.snapshot()).semanticResult).not.toBeNull();
      const sessionRoots = (await readdir(root, { withFileTypes: true })).filter(entry => entry.isDirectory());
      await expect.poll(async () => JSON.parse(await readFile(join(root, sessionRoots[0]!.name, "data/fake-completion-feedback.json"), "utf8"))).toMatchObject([
        { result: { content: [{ text: expect.stringContaining(feedback) }] } },
      ]);
    } finally {
      releaseFeedback();
      await session.close({ reason: "test complete" });
    }
  });

  it.each(["close", "interrupt"] as const)("settles bound completion before explicit %s", async operation => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-completion-stop-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-completion-stop-workspace-"));
    roots.push(root, workspace);
    let releaseFeedback!: () => void, feedbackStarted!: () => void;
    const started = new Promise<void>(resolve => { feedbackStarted = resolve; });
    const release = new Promise<void>(resolve => { releaseFeedback = resolve; });
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      completionFeedback: async () => { feedbackStarted(); await release; return "Accepted completion."; },
    });
    const session = await driver.openSession({ runId: "completion-stop", normalizedSessionId: "completion-stop", workingDirectory: workspace });
    try {
      await session.startTurn({ message: { role: "user", text: "finish" } });
      await started;
      let stopped = false;
      const stop = session[operation]({ reason: "fixture stop" }).then(() => { stopped = true; });
      await new Promise<void>(resolve => setImmediate(resolve));
      expect(stopped).toBe(false);
      releaseFeedback();
      await stop;
      expect((await session.snapshot()).semanticResult).not.toBeNull();
      const transcript = await session.transcript();
      expect(transcript.events.filter(event => event.eventType === "run.result.proposed")).toHaveLength(1);
      expect(transcript.events.some(event => event.eventType === "item.completed" && (event.payload.item as { is_error?: boolean })?.is_error)).toBe(false);
    } finally {
      releaseFeedback();
      await session.close({ reason: "test complete" });
    }
  });

  it("rejects malformed SSE frames", async () => {
    const stream = (value: string) =>
      new ReadableStream<Uint8Array>({
        start(controller) {
          controller.enqueue(new TextEncoder().encode(value));
          controller.close();
        },
      });
    const consume = async (value: string) => {
      for await (const _event of openCodeServerDriverInternals.parseSse(
        stream(value),
      )) {
        // Consume the complete stream so parse failures are observed.
      }
    };
    await expect(consume("data: {bad json}\n\n")).rejects.toThrow();
  });

  it("keeps the turn and the tool outcome when OpenCode sends an event above the payload limit", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-oversized-sse-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-oversized-sse-workspace-"));
    roots.push(root, workspace);
    let stream!: ReadableStreamDefaultController<Uint8Array>;
    let streamOpened!: () => void;
    const opened = new Promise<void>(resolve => { streamOpened = resolve; });
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      fetch: async (input, init) => String(input).endsWith("/event")
        ? new Response(new ReadableStream<Uint8Array>({ start(controller) { stream = controller; streamOpened(); } }), { headers: { "Content-Type": "text/event-stream" } })
        : fetch(input, init),
    });
    const session = await driver.openSession({ runId: "oversized-sse", normalizedSessionId: "oversized-sse", workingDirectory: workspace });
    try {
      const sessionID = session.ids().providerSessionId;
      const events = collectTurnEvents(session.events());
      await session.startTurn({ message: { role: "user", text: "run the full suite" } });
      await opened;
      const tail = "\nTests: 1 failed, 812 passed\nexit status 1";
      const output = "test output line\n".repeat(150_000) + tail;
      const send = (value: unknown) => {
        const bytes = new TextEncoder().encode(`data: ${JSON.stringify(value)}\n\n`);
        for (let index = 0; index < bytes.length; index += 64 * 1024)
          stream.enqueue(bytes.subarray(index, index + 64 * 1024));
      };
      send({ type: "message.updated", properties: { info: { id: "msg_oversized", role: "assistant", sessionID } } });
      send({ type: "message.part.updated", properties: { part: {
        id: "prt_oversized", messageID: "msg_oversized", sessionID, type: "tool", callID: "call_oversized", tool: "bash",
        state: { status: "completed", input: { command: "pnpm test" }, output, title: "pnpm test", metadata: { exit: 1, output }, time: { start: 1, end: 2 } },
      } } });
      send({ type: "session.idle", properties: { sessionID } });
      const observed = await events;
      expect(observed.at(-1)?.eventType).toBe("turn.completed");
      const diagnostics = observed.filter(event => event.eventType === "harness.diagnostic");
      expect(diagnostics.map(event => event.payload.code)).toEqual(["opencode_sse_event_compacted"]);
      const tool = observed.find(event => event.eventType === "tool.execution.completed" && event.payload.executionId === "prt_oversized");
      expect(tool?.payload).toMatchObject({
        name: "bash",
        status: "completed",
        outputBytes: Buffer.byteLength(output),
        outputTruncated: true,
        outputDigest: null,
      });
      expect(String(tool?.payload.output).endsWith(tail)).toBe(true);
    } finally {
      await session.close({ reason: "test complete" });
    }
  });

  it("fails the running turn with the exit cause when OpenCode stops mid-turn", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-server-lost-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-server-lost-workspace-"));
    roots.push(root, workspace);
    let stream!: ReadableStreamDefaultController<Uint8Array>;
    let streamOpened!: () => void;
    const opened = new Promise<void>(resolve => { streamOpened = resolve; });
    let serverPid: number | undefined;
    let eventRequests = 0;
    const refused = () => new TypeError("fetch failed", {
      cause: Object.assign(new Error("connect ECONNREFUSED 127.0.0.1"), { code: "ECONNREFUSED" }),
    });
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731", runtimeDirectory: root, command: fixture,
      environment: { PATH: process.env.PATH, OPENROUTER_API_KEY: "fixture-key" },
      onSpawn: async ({ pid }) => { serverPid = pid; },
      // Own the event stream so the fixture cannot finish the turn on its own,
      // then report the refused reconnects a dead server produces.
      fetch: async (input, init) => {
        if (!String(input).endsWith("/event")) return fetch(input, init);
        eventRequests += 1;
        if (eventRequests > 1) throw refused();
        return new Response(new ReadableStream<Uint8Array>({ start(controller) { stream = controller; streamOpened(); } }),
          { headers: { "Content-Type": "text/event-stream" } });
      },
    });
    const session = await driver.openSession({ runId: "server-lost", normalizedSessionId: "server-lost", workingDirectory: workspace });
    try {
      const events = collectTurnEvents(session.events());
      const turn = await session.startTurn({ message: { role: "user", text: "install dependencies" } });
      await opened;
      process.kill(serverPid!, "SIGKILL");
      stream.error(refused());
      const observed = await events;
      const failed = observed.at(-1);
      expect(failed).toMatchObject({
        eventType: "turn.failed",
        turnId: turn.turnId,
        payload: {
          status: "failed",
          providerTerminalObserved: false,
          error: {
            code: "opencode_server_exited",
            opencodeFailure: { kind: "server_exited", signal: "SIGKILL", connectionError: "ECONNREFUSED" },
          },
        },
      });
      const diagnostic = observed.find(event => event.eventType === "harness.diagnostic" && event.payload.code === "opencode_sse_failed");
      expect(diagnostic?.payload.failure).toEqual({ kind: "server_exited", signal: "SIGKILL", connectionError: "ECONNREFUSED" });
      expect(eventRequests).toBe(4);
    } finally {
      await session.close({ reason: "test complete" });
    }
  });

  it("classifies a lost event stream from closed error fields only", async () => {
    const { openCodeEventStreamFailure } = openCodeServerDriverInternals;
    const running = Object.assign(new EventEmitter(), { exitCode: null, signalCode: null }) as unknown as ChildProcess;
    const exited = Object.assign(new EventEmitter(), { exitCode: 137, signalCode: null }) as unknown as ChildProcess;
    const reset = new TypeError("fetch failed", { cause: Object.assign(new Error("private socket detail"), { code: "ECONNRESET" }) });
    expect(await openCodeEventStreamFailure(reset, exited)).toEqual({ kind: "server_exited", exitCode: 137, connectionError: "ECONNRESET" });
    expect(await openCodeEventStreamFailure(Object.assign(new Error("HTTP 502"), { httpStatus: 502 }), running))
      .toEqual({ kind: "http_error", httpStatus: 502 });
    expect(await openCodeEventStreamFailure(Object.assign(new Error("closed"), { streamClosed: true }), running))
      .toEqual({ kind: "stream_closed" });
    expect(await openCodeEventStreamFailure(new Error("private provider text"), running)).toEqual({ kind: "stream_error" });
    const unknownCode = new TypeError("fetch failed", { cause: Object.assign(new Error("x"), { code: "EPRIVATE" }) });
    const started = Date.now();
    expect(await openCodeEventStreamFailure(unknownCode, running)).toEqual({ kind: "connection_failed", connectionError: "unrecognized" });
    expect(Date.now() - started).toBeGreaterThanOrEqual(900);
  });

  it("restarts OpenCode when session startup fails transiently", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    let failSessionCreate = true;
    const spawns: number[] = [];
    const commandLifecycle: string[] = [];
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
      },
      commandLifecycle: {
        beforeSpawn: () => {
          commandLifecycle.push("before");
        },
        afterSpawn: () => {
          commandLifecycle.push("after");
        },
        afterExit: () => {
          commandLifecycle.push("exit");
        },
      },
      fetch: async (input, init) => {
        if (
          failSessionCreate &&
          String(input).endsWith("/session") &&
          init?.method === "POST"
        ) {
          failSessionCreate = false;
          throw new Error("transient session initialization failure");
        }
        return fetch(input, init);
      },
      onSpawn: async ({ pid }) => {
        spawns.push(pid);
      },
    });
    const session = await driver.openSession({
      runId: "run-retry",
      normalizedSessionId: "retry",
      workingDirectory: workspace,
    });
    expect(session.ids().providerSessionId).toBe("ses_fake_1");
    expect(spawns.length).toBeGreaterThanOrEqual(2);
    expect(spawns.length).toBeLessThanOrEqual(3);
    expect(commandLifecycle).toEqual(
      [...Array.from({ length: spawns.length - 1 }, () => ["before", "after", "exit"]).flat(), "before", "after"],
    );
    await session.close({ reason: "test" });
    expect(commandLifecycle).toEqual(
      Array.from({ length: spawns.length }, () => ["before", "after", "exit"]).flat(),
    );
  });

  it("releases the executable binding when spawning fails before health checks", async () => {
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-spawn-error-"));
    roots.push(root);
    const lifecycle: string[] = [];
    const driver = new OpenCodeServerDriver({
      model: "openrouter/deepseek/deepseek-v4-flash-0731",
      runtimeDirectory: root,
      command: join(root, "missing-executable"),
      commandLifecycle: {
        beforeSpawn: () => { lifecycle.push("before"); },
        afterSpawn: () => { lifecycle.push("spawned"); },
        afterExit: () => { lifecycle.push("released"); },
      },
    });
    await expect(driver.openSession({ runId: "spawn-error", normalizedSessionId: "spawn-error",
      workingDirectory: root })).rejects.toThrow("ENOENT");
    expect(lifecycle).toEqual(["before", "released"]);
  });

  it("reports startup exit details with stderr captured after spawn and redacted", async () => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(
      join(tmpdir(), "paperclip-opencode-workspace-"),
    );
    roots.push(root, workspace);
    const exitingFixture = join(root, "exit-before-health.mjs");
    await writeFile(
      exitingFixture,
      "#!/usr/bin/env node\nimport { readFileSync } from 'node:fs';\nconst config = JSON.parse(readFileSync(`${process.env.XDG_CONFIG_HOME}/opencode/opencode.json`, 'utf8'));\nprocess.stderr.write(`credential=${process.env.OPENROUTER_API_KEY}\\ngateway=${config.provider.paperclip.options.apiKey}\\nauthorization=super-secret-opencode-token\\n`);\nprocess.exit(17);\n",
      { mode: 0o755 },
    );
    const diagnostics: string[] = [];
    const driver = new OpenCodeServerDriver({
      model: "paperclip/team/model-alias",
      runtimeDirectory: root,
      command: exitingFixture,
      onDiagnostic: (message) => { diagnostics.push(message); },
      environment: {
        PATH: process.env.PATH,
        OPENROUTER_API_KEY: "fixture-key",
        PAPERCLIP_AI_PROVIDER_KEY: "fixture-custom-gateway-key",
        PAPERCLIP_AI_PROVIDER_URL: "https://gateway.example/v1",
      },
    });
    const error = await driver
      .openSession({
        runId: "run-startup-exit",
        normalizedSessionId: "startup-exit",
        workingDirectory: workspace,
      })
      .then(
        () => "provider unexpectedly started",
        (cause: unknown) => String(cause),
      );
    expect(error).toContain("provider_process_exited");
    expect(error).toContain("provider=opencode");
    expect(error).toContain("stage=health");
    expect(error).toContain("[REDACTED]");
    expect(error).not.toContain("fixture-key");
    expect(error).not.toContain("fixture-custom-gateway-key");
    expect(error).not.toContain("super-secret-opencode-token");
    expect(diagnostics.join("")).toContain("gateway=[REDACTED]");
    expect(diagnostics.join("")).not.toContain("fixture-custom-gateway-key");
  });

  it.each(["network", "response"])("redacts custom gateway keys in %s errors", async (failure) => {
    await chmod(fixture, 0o755);
    const root = await mkdtemp(join(tmpdir(), "paperclip-opencode-driver-"));
    const workspace = await mkdtemp(join(tmpdir(), "paperclip-opencode-workspace-"));
    roots.push(root, workspace);
    const key = "fixture-custom-gateway-key";
    const driver = new OpenCodeServerDriver({
      model: "paperclip/team/model-alias",
      runtimeDirectory: root,
      command: fixture,
      environment: {
        PATH: process.env.PATH,
        PAPERCLIP_AI_PROVIDER_KEY: key,
        PAPERCLIP_AI_PROVIDER_URL: "https://gateway.example/v1",
      },
      fetch: async (input, init) => {
        if (String(input).endsWith("/session") && init?.method === "POST") {
          if (failure === "network") throw new Error(`Gateway rejected ${key}`);
          return new Response(`Gateway rejected ${key}`, { status: 400 });
        }
        return fetch(input, init);
      },
    });
    const error = await driver.openSession({
      runId: "run-gateway-error",
      normalizedSessionId: "gateway-error",
      workingDirectory: workspace,
    }).then(() => "provider unexpectedly started", (cause: unknown) => String(cause));
    expect(error).toContain("Gateway rejected [REDACTED]");
    expect(error).not.toContain(key);
  });
});