test: add deadlock case

Author: JakobJingleheimer

test/known_issues/hooks-thread/a/hooks.mjs

@@ -0,0 +1,23 @@
+let port;
+
+export function initialize(data) {
+  ({ port } = data);
+}
+
+export function resolve(specifier, context, nextResolve) {
+  const id = ''+Math.random();
+  port.postMessage({
+    context,
+    id,
+    specifier,
+  });
+
+  return new Promise((resolve) => {
+    port.on('message', (message) => {
+      if (message.id !== id) return;
+
+      port.off('message', onMessage);
+      resolve({ url: message.specifier });
+    });
+  });
+}

test/known_issues/hooks-thread/a/register.mjs

@@ -0,0 +1,15 @@
+import { register } from 'node:module';
+import { MessageChannel } from 'node:worker_threads';
+
+const { port1, port2 } = new MessageChannel();
+
+port1.unref();
+port2.unref();
+
+register((new URL('./hooks.mjs', import.meta.url)).href, {
+  data: {
+    port: port2,
+  },
+  parentURL: import.meta.url,
+  transferList: [port2],
+});

test/known_issues/hooks-thread/b/hooks.mjs

@@ -0,0 +1,9 @@
+// This file will not get loaded because of a deadlock trying to resolve it.
+
+export function resolve(specifier, context, nextResolve) {
+  return nextResolve(specifier, context, nextResolve);
+}
+
+export function load(url, context, nextLoad) {
+  return nextLoad(url, context, nextLoad);
+}

test/known_issues/hooks-thread/b/register.mjs

@@ -0,0 +1,9 @@
+import { register } from 'node:module';
+import { MessageChannel } from 'node:worker_threads';
+
+const { port1, port2 } = new MessageChannel();
+
+port1.unref();
+port2.unref();
+
+register((new URL('./hooks.mjs', import.meta.url)).href);

test/known_issues/hooks-thread/test-hooks-thread-deadlock.js

@@ -0,0 +1,42 @@
+const { mustNotCall } = require('../../common/index.js');
+const assert = require('node:assert');
+const { spawn } = require('node:child_process');
+const path = require('node:path');
+const { execPath } = require('node:process');
+const { describe, it } = require('node:test');
+
+describe('hooks deadlock', { concurrency: true }, () => {
+  it('will deadlock when a/hooks…resolve tries to contact the main thread during b/register', async () => {
+    let stderr = '';
+    let stdout = '';
+    // ! Do NOT use spawnSync here: it will deadlock.
+    const child = spawn(execPath, [
+      `--import=${path.resolve(__dirname, './a/register.mjs')}`,
+      `--import=${path.resolve(__dirname, './b/register.mjs')}`,
+      '--input-type=module',
+      '--eval',
+      'import.meta.url;console.log("done")',
+    ]);
+    child.stderr.setEncoding('utf8');
+    child.stderr.on('data', (data) => { stderr += data; });
+    child.stdout.setEncoding('utf8');
+    child.stdout.on('data', (data) => { stdout += data; });
+
+    child.on('close', () => mustNotCall('Deadlock should prevent closing'));
+
+    return new Promise((res, rej) => {
+      setTimeout(() => {
+        try {
+          assert.strictEqual(stderr, '');
+          assert.strictEqual(child.exitCode, null); // It hasn't ended
+          assert.strictEqual(child.signalCode, null); // It hasn't ended
+
+          assert.strictEqual(child.kill('SIGKILL'), true); // Deadlocked process must be forcibily killed.
+          res('deadlocked process terminated');
+        } catch (e) {
+          rej(e);
+        }
+      }, 5_000); // This should have finished well before 5 second.
+    });
+  });
+});