Add blocked event loop test

Author: timfish

test/basic.test.mjs

@@ -0,0 +1,90 @@
+import { spawnSync } from 'node:child_process';
+import { join } from 'node:path';
+import { describe, expect, test } from 'vitest';
+
+const __dirname = import.meta.dirname || new URL('.', import.meta.url).pathname;
+
+describe('e2e Tests', () => {
+  test('Capture stack trace from multiple threads', () => {
+    const testFile = join(__dirname, 'stack-traces.js');
+    const result = spawnSync('node', [testFile])
+
+    expect(result.status).toBe(0);
+
+    const stacks = JSON.parse(result.stdout.toString());
+
+    expect(stacks['0']).toEqual(expect.arrayContaining([
+      {
+        function: 'pbkdf2Sync',
+        filename: expect.any(String),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: 'longWork',
+        filename: expect.stringMatching(/long-work.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: '?',
+        filename: expect.stringMatching(/stack-traces.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+    ]));
+
+    expect(stacks['2']).toEqual(expect.arrayContaining([
+      {
+        function: 'pbkdf2Sync',
+        filename: expect.any(String),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: 'longWork',
+        filename: expect.stringMatching(/long-work.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: '?',
+        filename: expect.stringMatching(/worker.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+    ]));
+  });
+
+  test('detect stalled thread', { timeout: 10000 }, () => {
+    const testFile = join(__dirname, 'stalled.js');
+    const result = spawnSync('node', [testFile]);
+
+    expect(result.status).toBe(0);
+
+    const stacks = JSON.parse(result.stdout.toString());
+
+    expect(stacks['0']).toEqual(expect.arrayContaining([
+      {
+        function: 'pbkdf2Sync',
+        filename: expect.any(String),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: 'longWork',
+        filename: expect.stringMatching(/long-work.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+      {
+        function: '?',
+        filename: expect.stringMatching(/stalled.js$/),
+        lineno: expect.any(Number),
+        colno: expect.any(Number),
+      },
+    ]));
+
+    expect(stacks['2'].length).toEqual(1);
+  });
+});

test/e2e.test.mjs

@@ -0,0 +1,11 @@
+const crypto = require('node:crypto');
+
+function longWork() {
+  for (let i = 0; i < 100; i++) {
+    const salt = crypto.randomBytes(128).toString('base64');
+    const hash = crypto.pbkdf2Sync('myPassword', salt, 10000, 512, 'sha512');
+    console.assert(hash);
+  }
+}
+
+module.exports = { longWork };

test/long-work.js

@@ -0,0 +1,11 @@
+const { Worker } = require('node:worker_threads');
+const { longWork } = require('./long-work.js');
+const { registerThread } = require('../lib/index.js');
+
+registerThread();
+
+const watchdog = new Worker('./test/watchdog.js');
+
+const worker = new Worker('./test/worker.js');
+
+longWork();

test/stack-traces.js

@@ -0,0 +1,15 @@
+const { captureStackTrace, getThreadsLastSeen } = require('../lib/index.js');
+
+const THRESHOLD = 500; // 1 second
+
+const timer = setInterval(() => {
+  for (const [_threadId, lastSeen] of Object.entries(getThreadsLastSeen())) {
+    if (lastSeen > THRESHOLD) {
+      // we don't want to run more than once
+      clearInterval(timer);
+      const stackTraces = captureStackTrace();
+      console.log(JSON.stringify(stackTraces));
+      process.exit(0)
+    }
+  }
+}, 500);

test/stalled-watchdog.js

@@ -0,0 +1,17 @@
+const { Worker } = require('node:worker_threads');
+const { longWork } = require('./long-work.js');
+const { registerThread } = require('../lib/index.js');
+
+setInterval(() => {
+  registerThread();
+}, 200).unref();
+
+const watchdog = new Worker('./test/stalled-watchdog.js');
+watchdog.on('exit', () => process.exit(0));
+
+const worker = new Worker('./test/worker-do-nothing.js');
+
+setTimeout(() => {
+  longWork();
+}, 2000);
+

test/stalled.js

@@ -0,0 +1,7 @@
+const { longWork } = require('./long-work');
+const { registerThread } = require('../lib/index.js');
+
+setInterval(() => {
+  registerThread();
+}, 200);
+

test/test.js

@@ -1,14 +1,6 @@
-const crypto = require('node:crypto');
-
+const { longWork } = require('./long-work');
 const { registerThread } = require('..');
 
 registerThread();
 
-function longWork() {
-    for (let i = 0; i < 100; i++) {
-        const salt = crypto.randomBytes(128).toString('base64');
-        const hash = crypto.pbkdf2Sync('myPassword', salt, 10000, 512, 'sha512');
-    }
-}
-
 longWork();