lib: export stable submodules in parent builtins

Author: Mesteery

lib/stream.js

@@ -22,6 +22,7 @@
 'use strict';
 
 const {
+  ObjectDefineProperties,
   ObjectDefineProperty,
   ObjectKeys,
   ReflectApply,
@@ -97,12 +98,26 @@ Stream.finished = eos;
 Stream.destroy = destroyer;
 Stream.compose = compose;
 
-ObjectDefineProperty(Stream, 'promises', {
-  configurable: true,
-  enumerable: true,
-  get() {
-    return promises;
-  }
+let consumers;
+let web;
+ObjectDefineProperties(Stream, {
+  // TODO: export stream/web when it is stable
+  consumers: {
+    configurable: true,
+    enumerable: true,
+    get() {
+      if (consumers === undefined)
+        consumers = require('stream/consumers');
+      return consumers;
+    }
+  },
+  promises: {
+    configurable: true,
+    enumerable: true,
+    get() {
+      return promises;
+    },
+  },
 });
 
 ObjectDefineProperty(pipeline, customPromisify, {

lib/timers.js

@@ -360,3 +360,13 @@ module.exports = {
     'timers.enroll() is deprecated. Please use setTimeout instead.',
     'DEP0095')
 };
+
+ObjectDefineProperty(module.exports, 'promises', {
+  configurable: true,
+  enumerable: true,
+  get() {
+    if (!timersPromises)
+      timersPromises = require('timers/promises');
+    return timersPromises;
+  },
+});