src: fix test runner coverage

PR-URL: #45055
Fixes: #45013
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

src/inspector_agent.cc

@@ -676,9 +676,6 @@ bool Agent::Start(const std::string& path,
                   const DebugOptions& options,
                   std::shared_ptr<ExclusiveAccess<HostPort>> host_port,
                   bool is_main) {
-  if (!options.allow_attaching_debugger) {
-    return false;
-  }
   path_ = path;
   debug_options_ = options;
   CHECK_NOT_NULL(host_port);
@@ -722,7 +719,8 @@ bool Agent::Start(const std::string& path,
   if (parent_handle_) {
     wait_for_connect = parent_handle_->WaitForConnect();
     parent_handle_->WorkerStarted(client_->getThreadHandle(), wait_for_connect);
-  } else if (!options.inspector_enabled || !StartIoThread()) {
+  } else if (!options.inspector_enabled || !options.allow_attaching_debugger ||
+             !StartIoThread()) {
     return false;
   }
 
@@ -917,6 +915,9 @@ void Agent::RequestIoThreadStart() {
   // We need to attempt to interrupt V8 flow (in case Node is running
   // continuous JS code) and to wake up libuv thread (in case Node is waiting
   // for IO events)
+  if (!options().allow_attaching_debugger) {
+    return;
+  }
   CHECK(start_io_thread_async_initialized);
   uv_async_send(&start_io_thread_async);
   parent_env_->RequestInterrupt([this](Environment*) {

test/parallel/test-runner-inspect.mjs

@@ -2,6 +2,8 @@ import * as common from '../common/index.mjs';
 import * as tmpdir from '../common/tmpdir.js';
 import * as fixtures from '../common/fixtures.mjs';
 import assert from 'node:assert';
+import path from 'node:path';
+import fs from 'node:fs/promises';
 import { NodeInstance } from '../common/inspector-helper.js';
 
 
@@ -52,3 +54,31 @@ tmpdir.refresh();
   assert.strictEqual(code, 1);
   assert.strictEqual(signal, null);
 }
+
+
+// Outputs coverage when event loop is drained, with no async logic.
+{
+  const coverageDirectory = path.join(tmpdir.path, 'coverage');
+  async function getCoveredFiles() {
+    const coverageFiles = await fs.readdir(coverageDirectory);
+    const files = new Set();
+    for (const coverageFile of coverageFiles) {
+      const coverage = JSON.parse(await fs.readFile(path.join(coverageDirectory, coverageFile)));
+      for (const { url } of coverage.result) {
+        if (!url.startsWith('node:')) files.add(url);
+      }
+    }
+    return files;
+  }
+
+  const { stderr, code, signal } = await common
+          .spawnPromisified(process.execPath,
+                            ['--test', fixtures.path('v8-coverage/basic.js')],
+                            { env: { ...process.env, NODE_V8_COVERAGE: coverageDirectory } });
+
+  assert.strictEqual(stderr, '');
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+  const files = await getCoveredFiles(coverageDirectory);
+  assert.ok(files.has(fixtures.fileURL('v8-coverage/basic.js').href));
+}