src: use internalBinding('config').hasInspector in JS land

Instead of `process.config.variables.v8_enable_inspector` which depends on the variable name in gyp files, or detecting `internalBinding('inspector').Connection`. PR-URL: #25291 Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: joyeecheung

lib/inspector.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const EventEmitter = require('events');
 const {
  ERR_INSPECTOR_ALREADY_CONNECTED,
  ERR_INSPECTOR_CLOSED,
@@ -9,13 +8,16 @@ const {
  ERR_INVALID_ARG_TYPE,
  ERR_INVALID_CALLBACK
 } = require('internal/errors').codes;
+
+const { hasInspector } = internalBinding('config');
+if (!hasInspector)
+ throw new ERR_INSPECTOR_NOT_AVAILABLE();
+
+const EventEmitter = require('events');
 const { validateString } = require('internal/validators');
 const util = require('util');
 const { Connection, open, url } = internalBinding('inspector');
 
-if (!Connection)
- throw new ERR_INSPECTOR_NOT_AVAILABLE();
-
 const connectionSymbol = Symbol('connectionProperty');
 const messageCallbacksSymbol = Symbol('messageCallbacks');
 const nextIdSymbol = Symbol('nextId');

lib/internal/bootstrap/cache.js

@@ -9,7 +9,7 @@ const { NativeModule } = require('internal/bootstrap/loaders');
 const {
  source, getCodeCache, compileFunction
 } = internalBinding('native_module');
-const { hasTracing } = process.binding('config');
+const { hasTracing, hasInspector } = process.binding('config');
 
 const depsModule = Object.keys(source).filter(
  (key) => NativeModule.isDepsModule(key) || key.startsWith('internal/deps')
@@ -33,7 +33,7 @@ const cannotUseCache = [
 
 // Skip modules that cannot be required when they are not
 // built into the binary.
-if (process.config.variables.v8_enable_inspector !== 1) {
+if (!hasInspector) {
  cannotUseCache.push(
  'inspector',
  'internal/util/inspector',

lib/internal/bootstrap/node.js

@@ -19,6 +19,7 @@
 const { internalBinding, NativeModule } = loaderExports;
 
 const { getOptionValue } = NativeModule.require('internal/options');
+const config = internalBinding('config');
 
 function startup() {
  setupTraceCategoryState();
@@ -164,7 +165,7 @@ function startup() {
  NativeModule.require('internal/process/coverage').setupExitHooks();
  }
 
- if (process.config.variables.v8_enable_inspector) {
+ if (config.hasInspector) {
  NativeModule.require('internal/inspector_async_hook').setup();
  }
 
@@ -280,7 +281,7 @@ function startup() {
 
  // TODO(joyeecheung): this property has not been well-maintained, should we
  // deprecate it in favor of a better API?
- const { isDebugBuild, hasOpenSSL } = internalBinding('config');
+ const { isDebugBuild, hasOpenSSL } = config;
  Object.defineProperty(process, 'features', {
  enumerable: true,
  writable: false,
@@ -630,7 +631,7 @@ function setupGlobalConsole() {
  writable: true
  });
  // TODO(joyeecheung): can we skip this if inspector is not active?
- if (process.config.variables.v8_enable_inspector) {
+ if (config.hasInspector) {
  const inspector =
  NativeModule.require('internal/console/inspector');
  inspector.addInspectorApis(consoleFromNode, consoleFromVM);

lib/internal/process/coverage.js

@@ -51,12 +51,13 @@ function disableAllAsyncHooks() {
 exports.writeCoverage = writeCoverage;
 
 function setup() {
- const { Connection } = internalBinding('inspector');
- if (!Connection) {
+ const { hasInspector } = internalBinding('config');
+ if (!hasInspector) {
  process._rawDebug('inspector not enabled');
  return;
  }
 
+ const { Connection } = internalBinding('inspector');
  coverageConnection = new Connection((res) => {
  if (coverageConnection._coverageCallback) {
  coverageConnection._coverageCallback(res);

lib/internal/util/inspector.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const hasInspector = process.config.variables.v8_enable_inspector === 1;
+const { hasInspector } = internalBinding('config');
 const inspector = hasInspector ? require('inspector') : undefined;
 
 let session;

src/node_config.cc

@@ -57,6 +57,12 @@ static void Initialize(Local<Object> target,
  READONLY_TRUE_PROPERTY(target, "hasTracing");
 #endif
 
+#if HAVE_INSPECTOR
+ READONLY_TRUE_PROPERTY(target, "hasInspector");
+#else
+ READONLY_FALSE_PROPERTY(target, "hasInspector");
+#endif
+
 #if !defined(NODE_WITHOUT_NODE_OPTIONS)
  READONLY_TRUE_PROPERTY(target, "hasNodeOptions");
 #endif