inspector: report all workers

Main thread (the one that WS endpoint connects to) should be able
to report all workers.

PR-URL: https://github.com/nodejs/node/pull/28872
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/test/parallel/test-inspector-workers-flat-list.js b/test/parallel/test-inspector-workers-flat-list.js
new file mode 100644
index 0000000000..9f6495d10f
--- /dev/null
+++ b/test/parallel/test-inspector-workers-flat-list.js
@@ -0,0 +1,78 @@
+'use strict';
+const common = require('../common');
+
+common.skipIfInspectorDisabled();
+
+const { Worker, isMainThread, parentPort, workerData } =
+  require('worker_threads');
+
+if (isMainThread || workerData !== 'launched by test') {
+  common.skipIfWorker();
+}
+
+const { Session } = require('inspector');
+
+const MAX_DEPTH = 3;
+
+let rootWorker = null;
+
+const runTest = common.mustCall(function() {
+  let reportedWorkersCount = 0;
+  const session = new Session();
+  session.connect();
+  session.on('NodeWorker.attachedToWorker', common.mustCall(
+    ({ params: { workerInfo } }) => {
+      console.log(`Worker ${workerInfo.title} was reported`);
+      if (++reportedWorkersCount === MAX_DEPTH) {
+        rootWorker.postMessage({ done: true });
+      }
+    }, MAX_DEPTH));
+  session.post('NodeWorker.enable', { waitForDebuggerOnStart: false });
+});
+
+function processMessage({ child }) {
+  console.log(`Worker ${child} is running`);
+  if (child === MAX_DEPTH) {
+    runTest();
+  }
+}
+
+function workerCallback(message) {
+  parentPort.postMessage(message);
+}
+
+function startWorker(depth, messageCallback) {
+  const worker = new Worker(__filename, { workerData: 'launched by test' });
+  worker.on('message', messageCallback);
+  worker.postMessage({ depth });
+  return worker;
+}
+
+function runMainThread() {
+  rootWorker = startWorker(1, processMessage);
+}
+
+function runChildWorkerThread() {
+  let worker = null;
+  parentPort.on('message', ({ child, depth, done }) => {
+    if (done) {
+      if (worker) {
+        worker.postMessage({ done: true });
+      }
+      parentPort.close();
+    } else if (depth) {
+      parentPort.postMessage({ child: depth });
+      if (depth < MAX_DEPTH) {
+        worker = startWorker(depth + 1, workerCallback);
+      }
+    } else if (child) {
+      parentPort.postMessage({ child });
+    }
+  });
+}
+
+if (isMainThread) {
+  runMainThread();
+} else {
+  runChildWorkerThread();
+}