test: terminate cluster worker in infinite loop

Verify that worker.process.kill() can terminate a cluster worker
stuck in an infinite loop.

PR-URL: #23165
Fixes: #22703
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

Author: cjihrig

test/parallel/test-cluster-kill-infinite-loop.js

@@ -0,0 +1,21 @@
+'use strict';
+const common = require('../common');
+const cluster = require('cluster');
+const assert = require('assert');
+
+if (cluster.isMaster) {
+  const worker = cluster.fork();
+
+  worker.on('online', common.mustCall(() => {
+    // Use worker.process.kill() instead of worker.kill() because the latter
+    // waits for a graceful disconnect, which will never happen.
+    worker.process.kill();
+  }));
+
+  worker.on('exit', common.mustCall((code, signal) => {
+    assert.strictEqual(code, null);
+    assert.strictEqual(signal, 'SIGTERM');
+  }));
+} else {
+  while (true) {}
+}