lib: add the Navigator object

Add the Navigator object with the Device Memory API.

Refs: #39540
Refs: https://html.spec.whatwg.org/multipage/system-state.html#the-navigator-object
Refs: https://w3c.github.io/device-memory

Co-authored-by: Voltrex <mohammadkeyvanzade94@gmail.com>

Author: Mesteery

.eslintrc.js

@@ -361,5 +361,6 @@ module.exports = {
     btoa: 'readable',
     atob: 'readable',
     performance: 'readable',
+    navigator: 'readable',
   },
 };

doc/api/globals.md

@@ -295,6 +295,58 @@ The `MessagePort` class. See [`MessagePort`][] for more details.
 
 This variable may appear to be global but is not. See [`module`][].
 
+## `navigator`
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+An implementation of the [Navigator API][]. Similar to [`window.navigator`][]
+in browsers.
+
+### `navigator.deviceMemory`
+<!-- YAML
+added: REPLACEME
+-->
+
+* {number}
+
+The total amount of device memory in GiB, rounded to the nearest power of 2,
+between 0.25 and 8 GiB. Part of the [Device Memory API][].
+
+```js
+console.log(`This device has ${navigator.deviceMemory} GiB of RAM`);
+```
+
+### `navigator.hardwareConcurrency`
+<!-- YAML
+added: REPLACEME
+-->
+
+* {integer}
+
+The number of logical processors.
+
+```js
+console.log(`This device has ${navigator.hardwareConcurrency} logical CPUs`);
+```
+
+### `navigator.platform`
+<!-- YAML
+added: REPLACEME
+-->
+
+* {string}
+
+A string identifying the operating system platform on which the Node.js process
+is running. For example, it returns 'Linux' on Linux, 'Darwin' on macOS, and
+'Win32' on Windows.
+
+```js
+console.log(`This process is running on ${navigator.platform}`);
+```
+
 ## `performance`
 
 The [`perf_hooks.performance`][] object.
@@ -429,6 +481,8 @@ The object that acts as the namespace for all W3C
 [WebAssembly][webassembly-org] related functionality. See the
 [Mozilla Developer Network][webassembly-mdn] for usage and compatibility.
 
+[Device Memory API]: https://w3c.github.io/device-memory/
+[Navigator API]: https://html.spec.whatwg.org/multipage/system-state.html#the-navigator-object
 [`AbortController`]: https://developer.mozilla.org/en-US/docs/Web/API/AbortController
 [`EventTarget` and `Event` API]: events.md#event-target-and-event-api
 [`MessageChannel`]: worker_threads.md#worker_threads_class_messagechannel
@@ -455,6 +509,7 @@ The object that acts as the namespace for all W3C
 [`setImmediate`]: timers.md#timers_setimmediate_callback_args
 [`setInterval`]: timers.md#timers_setinterval_callback_delay_args
 [`setTimeout`]: timers.md#timers_settimeout_callback_delay_args
+[`window.navigator`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/navigator
 [buffer section]: buffer.md
 [built-in objects]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects
 [module system documentation]: modules.md

lib/internal/bootstrap/node.js

@@ -241,6 +241,14 @@ if (!config.noBrowserGlobals) {
 
   defineOperation(globalThis, 'queueMicrotask', queueMicrotask);
 
+  // https://html.spec.whatwg.org/multipage/system-state.html#the-navigator-object
+  ObjectDefineProperty(globalThis, 'navigator', {
+    enumerable: true,
+    configurable: true,
+    writable: false,
+    value: require('internal/navigator'),
+  });
+
   // https://www.w3.org/TR/hr-time-2/#the-performance-attribute
   defineReplacableAttribute(globalThis, 'performance',
                             require('perf_hooks').performance);

lib/internal/navigator.js

@@ -0,0 +1,67 @@
+'use strict';
+
+const {
+  ObjectDefineProperties,
+  ObjectSetPrototypeOf,
+  MathClz32,
+} = primordials;
+
+const {
+  codes: {
+    ERR_ILLEGAL_CONSTRUCTOR,
+  }
+} = require('internal/errors');
+
+const {
+  getCPUs,
+  getOSInformation,
+  getTotalMem,
+} = internalBinding('os');
+
+class Navigator {
+  constructor() {
+    throw new ERR_ILLEGAL_CONSTRUCTOR();
+  }
+}
+
+class InternalNavigator {}
+InternalNavigator.prototype.constructor = Navigator.prototype.constructor;
+ObjectSetPrototypeOf(InternalNavigator.prototype, Navigator.prototype);
+
+function getDeviceMemory() {
+  const mem = getTotalMem() / 1024 / 1024;
+  if (mem <= 0.25 * 1024) return 0.25;
+  if (mem >= 8 * 1024) return 8;
+  const lowerBound = 1 << 31 - MathClz32(mem - 1);
+  const upperBound = lowerBound * 2;
+  return mem - lowerBound <= upperBound - mem ?
+    lowerBound / 1024 :
+    upperBound / 1024;
+}
+
+function getPlatform() {
+  if (process.platform === 'win32') return 'Win32';
+  if (process.platform === 'android') return 'Android';
+  return getOSInformation()[0];
+}
+
+const cpuData = getCPUs();
+ObjectDefineProperties(Navigator.prototype, {
+  deviceMemory: {
+    configurable: true,
+    enumerable: true,
+    value: getDeviceMemory(),
+  },
+  hardwareConcurrency: {
+    configurable: true,
+    enumerable: true,
+    value: cpuData ? cpuData.length / 7 : 1,
+  },
+  platform: {
+    configurable: true,
+    enumerable: true,
+    value: getPlatform(),
+  },
+});
+
+module.exports = new InternalNavigator();

test/common/index.js

@@ -282,7 +282,9 @@ if (global.AbortController)
 if (global.gc) {
   knownGlobals.push(global.gc);
 }
-
+if (global.navigator) {
+  knownGlobals.push(global.navigator);
+}
 if (global.performance) {
   knownGlobals.push(global.performance);
 }

test/fixtures/wpt/LICENSE.md

@@ -1,6 +1,6 @@
 # The 3-Clause BSD License
 
-Copyright 2019 web-platform-tests contributors
+Copyright © web-platform-tests contributors
 
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 

test/fixtures/wpt/README.md

@@ -12,14 +12,15 @@ Last update:
 
 - common: https://github.com/web-platform-tests/wpt/tree/bb97a68974/common
 - console: https://github.com/web-platform-tests/wpt/tree/3b1f72e99a/console
+- device-memory: https://github.com/web-platform-tests/wpt/tree/c0cdd63f19/device-memory
 - dom/abort: https://github.com/web-platform-tests/wpt/tree/1728d198c9/dom/abort
 - encoding: https://github.com/web-platform-tests/wpt/tree/35f70910d3/encoding
 - FileAPI: https://github.com/web-platform-tests/wpt/tree/3b279420d4/FileAPI
 - hr-time: https://github.com/web-platform-tests/wpt/tree/9910784394/hr-time
 - html/webappapis/atob: https://github.com/web-platform-tests/wpt/tree/f267e1dca6/html/webappapis/atob
 - html/webappapis/microtask-queuing: https://github.com/web-platform-tests/wpt/tree/2c5c3c4c27/html/webappapis/microtask-queuing
 - html/webappapis/timers: https://github.com/web-platform-tests/wpt/tree/5873f2d8f1/html/webappapis/timers
-- interfaces: https://github.com/web-platform-tests/wpt/tree/80a4176623/interfaces
+- interfaces: https://github.com/web-platform-tests/wpt/tree/fc086c82d5/interfaces
 - performance-timeline: https://github.com/web-platform-tests/wpt/tree/17ebc3aea0/performance-timeline
 - resources: https://github.com/web-platform-tests/wpt/tree/972ca5b669/resources
 - streams: https://github.com/web-platform-tests/wpt/tree/8f60d94439/streams

test/fixtures/wpt/device-memory/META.yml

@@ -0,0 +1,3 @@
+spec: https://w3c.github.io/device-memory/
+suggested_reviewers:
+  - npm1

test/fixtures/wpt/device-memory/device-memory.https.any.js

@@ -0,0 +1,8 @@
+test(function() {
+    assert_equals(typeof navigator.deviceMemory, "number",
+        "navigator.deviceMemory returns a number");
+    assert_true(navigator.deviceMemory >= 0,
+        "navigator.deviceMemory returns a positive value");
+    assert_true([0.25, 0.5, 1, 2, 4, 8].includes(navigator.deviceMemory),
+        "navigator.deviceMemory returns a power of 2 between 0.25 and 8");
+}, "navigator.deviceMemory is a positive number, a power of 2, between 0.25 and 8");

test/fixtures/wpt/device-memory/idlharness.https.any.js

@@ -0,0 +1,19 @@
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+// META: timeout=long
+
+// https://w3c.github.io/device-memory/
+
+"use strict";
+
+idl_test(
+  ['device-memory'],
+  ['html'],
+  async idl_array => {
+    if (self.GLOBAL.isWorker()) {
+      idl_array.add_objects({ WorkerNavigator: ['navigator'] });
+    } else {
+      idl_array.add_objects({ Navigator: ['navigator'] });
+    }
+  }
+);