node/test/parallel/test-inspect-async-hook-setup-at-inspect.js

'use strict';
const common = require('../common');
common.skipIfInspectorDisabled();
common.skipIf32Bits();
const { NodeInstance } = require('../common/inspector-helper.js');
const assert = require('assert');

// Even with --inspect, the default async call stack depth is 0. We need a
// chance to call Debugger.setAsyncCallStackDepth *before* activating the timer
// for async stack traces to work.
const script = `
process._rawDebug('Waiting until the inspector is activated...');
const waiting = setInterval(() => { debugger; }, 50);

// This function is called by the inspector client (session)
function setupTimeoutWithBreak() {
  clearInterval(waiting);
  process._rawDebug('Debugger ready, setting up timeout with a break');
  setTimeout(() => { debugger; }, 50);
}
`;

async function waitForInitialSetup(session) {
  console.error('[test]', 'Waiting for initial setup');
  await session.waitForBreakOnLine(2, '[eval]');
}

// Sent only once the target is paused. While the target runs JS the command
// is dispatched from a V8 interrupt, where Agent::SyncAsyncHookState() cannot
// call into JS and defers enabling the async hook to an immediate that the
// pause then blocks, answering the command anyway. Dispatching from the paused
// message loop enables the hook inline, so the response is a real barrier.
async function enableAsyncStackTraces(session) {
  console.error('[test]', 'Enabling async stack traces');
  await session.send({ 'method': 'Debugger.setAsyncCallStackDepth',
                       'params': { 'maxDepth': 10 } });
}

async function setupTimeoutForStackTrace(session) {
  console.error('[test]', 'Setting up timeout for async stack trace');
  await session.send([
    { 'method': 'Runtime.evaluate',
      'params': { expression: 'setupTimeoutWithBreak()' } },
    { 'method': 'Debugger.resume' },
  ]);
}

async function checkAsyncStackTrace(session) {
  console.error('[test]', 'Verify basic properties of asyncStackTrace');
  const paused = await session.waitForBreakOnLine(8, '[eval]');
  assert(paused.params.asyncStackTrace,
         `${Object.keys(paused.params)} contains "asyncStackTrace" property`);
  assert(paused.params.asyncStackTrace.description, 'Timeout');
  assert(paused.params.asyncStackTrace.callFrames
           .some((frame) => frame.functionName === 'setupTimeoutWithBreak'));
}

async function runTests() {
  const instance = new NodeInstance(['--inspect=0'], script);
  const session = await instance.connectInspectorSession();
  await session.send([
    { 'method': 'Runtime.enable' },
    { 'method': 'Debugger.enable' },
    { 'method': 'Debugger.setBlackboxPatterns',
      'params': { 'patterns': [] } },
  ]);

  await waitForInitialSetup(session);
  await enableAsyncStackTraces(session);
  await setupTimeoutForStackTrace(session);
  await checkAsyncStackTrace(session);

  console.error('[test]', 'Stopping child instance');
  session.disconnect();
  instance.kill();
}

runTests();