node/test/parallel/test-worker-debug.js

'use strict';
const common = require('../common');

common.skipIfInspectorDisabled();

const assert = require('assert');
const EventEmitter = require('events');
const { Session } = require('inspector');
const { pathToFileURL } = require('url');
const {
  Worker, isMainThread, parentPort, workerData
} = require('worker_threads');


const workerMessage = 'This is a message from a worker';

function waitForMessage() {
  return new Promise((resolve) => {
    parentPort.once('message', resolve);
  });
}

// This is at the top so line numbers change less often
if (!isMainThread) {
  if (workerData === 1) {
    console.log(workerMessage);
    debugger;  // eslint-disable-line no-debugger
  } else if (workerData === 2) {
    parentPort.postMessage('running');
    waitForMessage();
  }
  return;
}

function doPost(session, method, params) {
  return new Promise((resolve, reject) => {
    session.post(method, params, (error, result) => {
      if (error)
        reject(JSON.stringify(error));
      else
        resolve(result);
    });
  });
}

function waitForEvent(emitter, event) {
  return new Promise((resolve) => emitter.once(event, resolve));
}

function waitForWorkerAttach(session) {
  return waitForEvent(session, 'NodeWorker.attachedToWorker')
      .then(({ params }) => params);
}

async function waitForWorkerDetach(session, id) {
  let sessionId;
  do {
    const { params } =
        await waitForEvent(session, 'NodeWorker.detachedFromWorker');
    sessionId = params.sessionId;
  } while (sessionId !== id);
}

function runWorker(id, workerCallback = () => {}) {
  return new Promise((resolve, reject) => {
    const worker = new Worker(__filename, { workerData: id });
    workerCallback(worker);
    worker.on('error', reject);
    worker.on('exit', resolve);
  });
}

class WorkerSession extends EventEmitter {
  constructor(parentSession, id) {
    super();
    this._parentSession = parentSession;
    this._id = id;
    this._requestCallbacks = new Map();
    this._nextCommandId = 1;
    this._parentSession.on('NodeWorker.receivedMessageFromWorker',
                           ({ params }) => {
                             if (params.sessionId === this._id)
                               this._processMessage(JSON.parse(params.message));
                           });
  }

  _processMessage(message) {
    if (message.id === undefined) {
      // console.log(JSON.stringify(message));
      this.emit('inspectorNotification', message);
      this.emit(message.method, message);
      return;
    }
    const callback = this._requestCallbacks.get(message.id);
    if (callback) {
      this._requestCallbacks.delete(message.id);
      if (message.error)
        callback[1](message.error.message);
      else
        callback[0](message.result);
    }
  }

  async waitForBreakAfterCommand(command, script, line) {
    const notificationPromise = waitForEvent(this, 'Debugger.paused');
    this.post(command);
    const notification = await notificationPromise;
    const callFrame = notification.params.callFrames[0];
    assert.strictEqual(callFrame.url, pathToFileURL(script).toString());
    assert.strictEqual(callFrame.location.lineNumber, line);
  }

  post(method, parameters) {
    const msg = {
      id: this._nextCommandId++,
      method
    };
    if (parameters)
      msg.params = parameters;

    return new Promise((resolve, reject) => {
      this._requestCallbacks.set(msg.id, [resolve, reject]);
      this._parentSession.post('NodeWorker.sendMessageToWorker', {
        sessionId: this._id, message: JSON.stringify(msg)
      });
    });
  }
}

async function testBasicWorkerDebug(session, post) {
  /*
    1. Do 'enable' with waitForDebuggerOnStart = true
    2. Run worker. It should break on start.
    3. Enable Runtime (to get console message) and Debugger. Resume.
    4. Breaks on the 'debugger' statement. Resume.
    5. Console message received, worker runs to a completion.
    6. contextCreated/contextDestroyed had been properly dispatched
  */
  console.log('Test basic debug scenario');
  await post('NodeWorker.enable', { waitForDebuggerOnStart: true });
  const attached = waitForWorkerAttach(session);
  const worker = runWorker(1);
  const { sessionId, waitingForDebugger } = await attached;
  assert.strictEqual(waitingForDebugger, true);
  const detached = waitForWorkerDetach(session, sessionId);
  const workerSession = new WorkerSession(session, sessionId);
  const contextEvents = Promise.all([
    waitForEvent(workerSession, 'Runtime.executionContextCreated'),
    waitForEvent(workerSession, 'Runtime.executionContextDestroyed')
  ]);
  const consolePromise = waitForEvent(workerSession, 'Runtime.consoleAPICalled')
      .then((notification) => notification.params.args[0].value);
  await workerSession.post('Debugger.enable');
  await workerSession.post('Runtime.enable');
  await workerSession.waitForBreakAfterCommand(
    'Runtime.runIfWaitingForDebugger', __filename, 1);
  await workerSession.waitForBreakAfterCommand(
    'Debugger.resume', __filename, 26);  // V8 line number is zero-based
  assert.strictEqual(await consolePromise, workerMessage);
  workerSession.post('Debugger.resume');
  await Promise.all([worker, detached, contextEvents]);
}

async function testNoWaitOnStart(session, post) {
  console.log('Test disabled waitForDebuggerOnStart');
  await post('NodeWorker.enable', { waitForDebuggerOnStart: false });
  let worker;
  const promise = waitForWorkerAttach(session);
  const exitPromise = runWorker(2, (w) => { worker = w; });
  const { waitingForDebugger } = await promise;
  assert.strictEqual(waitingForDebugger, false);
  worker.postMessage('resume');
  await exitPromise;
}

async function testTwoWorkers(session, post) {
  console.log('Test attach to a running worker and then start a new one');
  await post('NodeWorker.disable');
  let okToAttach = false;
  const worker1attached = waitForWorkerAttach(session).then((notification) => {
    assert.strictEqual(okToAttach, true);
    return notification;
  });

  let worker1Exited;
  const worker = await new Promise((resolve, reject) => {
    worker1Exited = runWorker(2, resolve);
  }).then((worker) => new Promise(
    (resolve) => worker.once('message', () => resolve(worker))));
  okToAttach = true;
  await post('NodeWorker.enable', { waitForDebuggerOnStart: true });
  const { waitingForDebugger: worker1Waiting } = await worker1attached;
  assert.strictEqual(worker1Waiting, false);

  const worker2Attached = waitForWorkerAttach(session);
  let worker2Done = false;
  const worker2Exited = runWorker(1)
      .then(() => assert.strictEqual(worker2Done, true));
  const worker2AttachInfo = await worker2Attached;
  assert.strictEqual(worker2AttachInfo.waitingForDebugger, true);
  worker2Done = true;

  const workerSession = new WorkerSession(session, worker2AttachInfo.sessionId);
  workerSession.post('Runtime.runIfWaitingForDebugger');
  worker.postMessage('resume');
  await Promise.all([worker1Exited, worker2Exited]);
}

async function test() {
  const session = new Session();
  session.connect();
  const post = doPost.bind(null, session);

  await testBasicWorkerDebug(session, post);

  console.log('Test disabling attach to workers');
  await post('NodeWorker.disable');
  await runWorker(1);

  await testNoWaitOnStart(session, post);
  await testTwoWorkers(session, post);

  session.disconnect();
  console.log('Test done');
}

test();