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>

src/inspector/worker_inspector.h

@@ -55,6 +55,13 @@ class ParentInspectorHandle {
                         std::shared_ptr<MainThreadHandle> parent_thread,
                         bool wait_for_connect);
   ~ParentInspectorHandle();
+  std::unique_ptr<ParentInspectorHandle> NewParentInspectorHandle(
+      int thread_id, const std::string& url) {
+    return std::make_unique<ParentInspectorHandle>(thread_id,
+                                                   url,
+                                                   parent_thread_,
+                                                   wait_);
+  }
   void WorkerStarted(std::shared_ptr<MainThreadHandle> worker_thread,
                      bool waiting);
   bool WaitForConnect() {

src/inspector_agent.cc

@@ -237,8 +237,10 @@ class ChannelImpl final : public v8_inspector::V8Inspector::Channel,
     tracing_agent_ =
         std::make_unique<protocol::TracingAgent>(env, main_thread_);
     tracing_agent_->Wire(node_dispatcher_.get());
-    worker_agent_ = std::make_unique<protocol::WorkerAgent>(worker_manager);
+    if (worker_manager) {
-    worker_agent_->Wire(node_dispatcher_.get());
+      worker_agent_ = std::make_unique<protocol::WorkerAgent>(worker_manager);
+      worker_agent_->Wire(node_dispatcher_.get());
+    }
     runtime_agent_ = std::make_unique<protocol::RuntimeAgent>();
     runtime_agent_->Wire(node_dispatcher_.get());
   }
@@ -246,8 +248,10 @@ class ChannelImpl final : public v8_inspector::V8Inspector::Channel,
   ~ChannelImpl() override {
     tracing_agent_->disable();
     tracing_agent_.reset();  // Dispose before the dispatchers
-    worker_agent_->disable();
+    if (worker_agent_) {
-    worker_agent_.reset();  // Dispose before the dispatchers
+      worker_agent_->disable();
+      worker_agent_.reset();  // Dispose before the dispatchers
+    }
     runtime_agent_->disable();
     runtime_agent_.reset();  // Dispose before the dispatchers
   }
@@ -670,6 +674,9 @@ class NodeInspectorClient : public V8InspectorClient {
   }
 
   std::shared_ptr<WorkerManager> getWorkerManager() {
+    if (!is_main_) {
+      return nullptr;
+    }
     if (worker_manager_ == nullptr) {
       worker_manager_ =
           std::make_shared<WorkerManager>(getThreadHandle());
@@ -968,7 +975,11 @@ void Agent::SetParentHandle(
 
 std::unique_ptr<ParentInspectorHandle> Agent::GetParentHandle(
     int thread_id, const std::string& url) {
-  return client_->getWorkerManager()->NewParentHandle(thread_id, url);
+  if (!parent_handle_) {
+    return client_->getWorkerManager()->NewParentHandle(thread_id, url);
+  } else {
+    return parent_handle_->NewParentInspectorHandle(thread_id, url);
+  }
 }
 
 void Agent::WaitForConnect() {

test/parallel/test-inspector-async-hook-after-done.js

@@ -3,6 +3,7 @@
 const common = require('../common');
 
 common.skipIfInspectorDisabled();
+common.skipIfWorker();
 
 const assert = require('assert');
 const { Worker } = require('worker_threads');
@@ -12,9 +13,7 @@ const session = new Session();
 
 let done = false;
 
-session.connect();
+function onAttachToWorker({ params: { sessionId } }) {
-
-session.on('NodeWorker.attachedToWorker', ({ params: { sessionId } }) => {
   let id = 1;
   function postToWorkerInspector(method, params) {
     session.post('NodeWorker.sendMessageToWorker', {
@@ -47,7 +46,11 @@ session.on('NodeWorker.attachedToWorker', ({ params: { sessionId } }) => {
                         { enabled: true });
   // start worker
   postToWorkerInspector('Runtime.runIfWaitingForDebugger');
-});
+}
+
+session.connect();
+
+session.on('NodeWorker.attachedToWorker', common.mustCall(onAttachToWorker));
 
 session.post('NodeWorker.enable', { waitForDebuggerOnStart: true }, () => {
   new Worker('console.log("Worker is done")', { eval: true })

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();
+}