console: lazy load process.stderr and process.stdout

This patch:

- Refactors the Console constructor: moves the property binding code
  into and the writable streams binding code into two methods defined
  on the Console.prototype with symbols.
- Refactors the global console creation: we only need to share the
  property binding code from the Console constructor. To bind the
  streams we can lazy load `process.stdio` and `process.stderr`
  so that we don't create these streams when they are not used.
  This significantly reduces the number of modules loaded during
  bootstrap. Also, by calling the refactored-out method directly
  we can skip the unnecessary typechecks when creating the global
  console and there is no need to create a temporary Console
  anymore.
- Refactors the error handler creation and the `write` method:
  use a `kUseStdout` symbol to tell the internals which stream
  should be loaded from the console instance. Also put the
  `write` method on the Console prototype so it just loads
  other properties directly off the console instance which simplifies
  the call sites.

Also leaves a few TODOs for further refactoring of the console
bootstrap.

PR-URL: https://github.com/nodejs/node/pull/24534
Reviewed-By: Gus Caplan <me@gus.host>

1 files changed, 10 insertions, 8 deletions

diff --git a/test/parallel/test-bootstrap-modules.js b/test/parallel/test-bootstrap-modules.js
index 70011637e0..272dec4006 100644
--- a/test/parallel/test-bootstrap-modules.js
+++ b/test/parallel/test-bootstrap-modules.js
@@ -1,14 +1,16 @@
-/* eslint-disable node-core/required-modules */
-
+// Flags: --expose-internals
 'use strict';
 
-// Ordinarily test files must require('common') but that action causes
-// the global console to be compiled, defeating the purpose of this test.
-// This makes sure no additional files are added without carefully considering
-// lazy loading. Please adjust the value if necessary.
-
+// This list must be computed before we require any modules to
+// to eliminate the noise.
 const list = process.moduleLoadList.slice();
 
+const common = require('../common');
 const assert = require('assert');
 
-assert(list.length <= 78, list);
+const isMainThread = common.isMainThread;
+const kMaxModuleCount = isMainThread ? 56 : 78;
+
+assert(list.length <= kMaxModuleCount,
+       `Total length: ${list.length}\n` + list.join('\n')
+);