src: return void in InitializeInspector()

We have been ignoring inspector port binding errors during startup.
Handling this error would be a breaking change and it's probably
surprising to refuse to launch the Node.js instance simply because
the inspector cannot listen to the port anyway. So just turn the
return value of InitializeInspector() and remove the TODOs for
handling the error.

PR-URL: #44903
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/api/environment.cc

@@ -370,7 +370,6 @@ Environment* CreateEnvironment(
   Environment* env = new Environment(
       isolate_data, context, args, exec_args, nullptr, flags, thread_id);
 #if HAVE_INSPECTOR
-  // TODO(joyeecheung): handle the exit code returned by InitializeInspector().
   if (env->should_create_inspector()) {
     if (inspector_parent_handle) {
       env->InitializeInspector(

src/env.h

@@ -617,7 +617,7 @@ class Environment : public MemoryRetainer {
 #if HAVE_INSPECTOR
   // If the environment is created for a worker, pass parent_handle and
   // the ownership if transferred into the Environment.
-  ExitCode InitializeInspector(
+  void InitializeInspector(
       std::unique_ptr<inspector::ParentInspectorHandle> parent_handle);
 #endif
 

src/node.cc

@@ -166,7 +166,7 @@ void SignalExit(int signo, siginfo_t* info, void* ucontext) {
 #endif  // __POSIX__
 
 #if HAVE_INSPECTOR
-ExitCode Environment::InitializeInspector(
+void Environment::InitializeInspector(
     std::unique_ptr<inspector::ParentInspectorHandle> parent_handle) {
   std::string inspector_path;
   bool is_main = !parent_handle;
@@ -187,7 +187,7 @@ ExitCode Environment::InitializeInspector(
                           is_main);
   if (options_->debug_options().inspector_enabled &&
       !inspector_agent_->IsListening()) {
-    return ExitCode::kInvalidCommandLineArgument2;  // Signal internal error
+    return;
   }
 
   profiler::StartProfilers(this);
@@ -196,7 +196,7 @@ ExitCode Environment::InitializeInspector(
     inspector_agent_->PauseOnNextJavascriptStatement("Break at bootstrap");
   }
 
-  return ExitCode::kNoFailure;
+  return;
 }
 #endif  // HAVE_INSPECTOR
 

src/node_main_instance.cc

@@ -181,8 +181,6 @@ NodeMainInstance::CreateMainEnvironment(ExitCode* exit_code) {
     SetIsolateErrorHandlers(isolate_, {});
     env->InitializeMainContext(context, &(snapshot_data_->env_info));
 #if HAVE_INSPECTOR
-    // TODO(joyeecheung): handle the exit code returned by
-    // InitializeInspector().
     env->InitializeInspector({});
 #endif
 
@@ -201,8 +199,6 @@ NodeMainInstance::CreateMainEnvironment(ExitCode* exit_code) {
                               EnvironmentFlags::kDefaultFlags,
                               {}));
 #if HAVE_INSPECTOR
-    // TODO(joyeecheung): handle the exit code returned by
-    // InitializeInspector().
     env->InitializeInspector({});
 #endif
     if (env->principal_realm()->RunBootstrapping().IsEmpty()) {

src/node_snapshotable.cc

@@ -1173,8 +1173,6 @@ ExitCode SnapshotBuilder::Generate(SnapshotData* out,
       // in the future).
       if (snapshot_type == SnapshotMetadata::Type::kFullyCustomized) {
 #if HAVE_INSPECTOR
-        // TODO(joyeecheung): handle the exit code returned by
-        // InitializeInspector().
         env->InitializeInspector({});
 #endif
         if (LoadEnvironment(env, StartExecutionCallback{}).IsEmpty()) {

test/parallel/test-inspect-address-in-use.js

@@ -0,0 +1,59 @@
+'use strict';
+const common = require('../common');
+common.skipIfInspectorDisabled();
+
+const { spawnSync } = require('child_process');
+const { createServer } = require('http');
+const assert = require('assert');
+const fixtures = require('../common/fixtures');
+const entry = fixtures.path('empty.js');
+const { Worker } = require('worker_threads');
+
+function testOnServerListen(fn) {
+  const server = createServer((socket) => {
+    socket.end('echo');
+  });
+
+  server.on('listening', () => {
+    fn(server);
+    server.close();
+  });
+  server.listen(0, '127.0.0.1');
+}
+
+function testChildProcess(getArgs, exitCode) {
+  testOnServerListen((server) => {
+    const { port } = server.address();
+    const child = spawnSync(process.execPath, getArgs(port));
+    const stderr = child.stderr.toString().trim();
+    const stdout = child.stdout.toString().trim();
+    console.log('[STDERR]');
+    console.log(stderr);
+    console.log('[STDOUT]');
+    console.log(stdout);
+    const match = stderr.match(
+      /Starting inspector on 127\.0\.0\.1:(\d+) failed: address already in use/
+    );
+    assert.notStrictEqual(match, null);
+    assert.strictEqual(match[1], port + '');
+    assert.strictEqual(child.status, exitCode);
+  });
+}
+
+testChildProcess(
+  (port) => [`--inspect=${port}`, '--build-snapshot', entry], 0);
+testChildProcess(
+  (port) => [`--inspect=${port}`, entry], 0);
+
+testOnServerListen((server) => {
+  const { port } = server.address();
+  const worker = new Worker(entry, {
+    execArgv: [`--inspect=${port}`]
+  });
+
+  worker.on('error', common.mustNotCall());
+
+  worker.on('exit', common.mustCall((code) => {
+    assert.strictEqual(code, 0);
+  }));
+});