lib: add navigator.platform

PR-URL: https://github.com/nodejs/node/pull/50385
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/globals.md

@@ -637,6 +637,21 @@ logical processors available to the current Node.js instance.
 console.log(`This process is running on ${navigator.hardwareConcurrency} logical processors`);
 ```
 
+### `navigator.platform`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* {string}
+
+The `navigator.platform` read-only property returns a string identifying the
+platform on which the Node.js instance is running.
+
+```js
+console.log(`This process is running on ${navigator.platform}`);
+```
+
 ### `navigator.userAgent`
 
 <!-- YAML

lib/internal/navigator.js

@@ -4,6 +4,7 @@ const {
   ObjectDefineProperties,
   StringPrototypeIndexOf,
   StringPrototypeSlice,
+  StringPrototypeToUpperCase,
   Symbol,
 } = primordials;
 
@@ -22,10 +23,57 @@ const {
 const kInitialize = Symbol('kInitialize');
 const nodeVersion = process.version;
 
+/**
+ * @param {object} process
+ * @param {string} process.platform
+ * @param {string} process.arch
+ * @returns {string}
+ */
+function getNavigatorPlatform(process) {
+  if (process.platform === 'darwin') {
+    // On macOS, modern browsers return 'MacIntel' even if running on Apple Silicon.
+    return 'MacIntel';
+  } else if (process.platform === 'win32') {
+    // On Windows, modern browsers return 'Win32' even if running on a 64-bit version of Windows.
+    // https://developer.mozilla.org/en-US/docs/Web/API/Navigator/platform#usage_notes
+    return 'Win32';
+  } else if (process.platform === 'linux') {
+    if (process.arch === 'ia32') {
+      return 'Linux i686';
+    } else if (process.arch === 'x64') {
+      return 'Linux x86_64';
+    }
+    return `Linux ${process.arch}`;
+  } else if (process.platform === 'freebsd') {
+    if (process.arch === 'ia32') {
+      return 'FreeBSD i386';
+    } else if (process.arch === 'x64') {
+      return 'FreeBSD amd64';
+    }
+    return `FreeBSD ${process.arch}`;
+  } else if (process.platform === 'openbsd') {
+    if (process.arch === 'ia32') {
+      return 'OpenBSD i386';
+    } else if (process.arch === 'x64') {
+      return 'OpenBSD amd64';
+    }
+    return `OpenBSD ${process.arch}`;
+  } else if (process.platform === 'sunos') {
+    if (process.arch === 'ia32') {
+      return 'SunOS i86pc';
+    }
+    return `SunOS ${process.arch}`;
+  } else if (process.platform === 'aix') {
+    return 'AIX';
+  }
+  return `${StringPrototypeToUpperCase(process.platform[0])}${StringPrototypeSlice(process.platform, 1)} ${process.arch}`;
+}
+
 class Navigator {
   // Private properties are used to avoid brand validations.
   #availableParallelism;
   #userAgent = `Node.js/${StringPrototypeSlice(nodeVersion, 1, StringPrototypeIndexOf(nodeVersion, '.'))}`;
+  #platform = getNavigatorPlatform(process);
 
   constructor() {
     if (arguments[0] === kInitialize) {
@@ -48,14 +96,23 @@ class Navigator {
   get userAgent() {
     return this.#userAgent;
   }
+
+  /**
+   * @return {string}
+   */
+  get platform() {
+    return this.#platform;
+  }
 }
 
 ObjectDefineProperties(Navigator.prototype, {
   hardwareConcurrency: kEnumerableProperty,
   userAgent: kEnumerableProperty,
+  platform: kEnumerableProperty,
 });
 
 module.exports = {
+  getNavigatorPlatform,
   navigator: new Navigator(kInitialize),
   Navigator,
 };

test/parallel/test-navigator.js

@@ -1,7 +1,10 @@
 'use strict';
 
+// Flags: --expose-internals
+
 require('../common');
 const assert = require('assert');
+const { getNavigatorPlatform } = require('internal/navigator');
 
 const is = {
   number: (value, key) => {
@@ -15,3 +18,59 @@ is.number(navigator.hardwareConcurrency, 'hardwareConcurrency');
 assert.ok(navigator.hardwareConcurrency > 0);
 assert.strictEqual(typeof navigator.userAgent, 'string');
 assert.match(navigator.userAgent, /^Node\.js\/\d+$/);
+
+assert.strictEqual(typeof navigator.platform, 'string');
+if (process.platform === 'darwin') {
+  assert.strictEqual(navigator.platform, 'MacIntel');
+} else if (process.platform === 'win32') {
+  assert.strictEqual(navigator.platform, 'Win32');
+} else if (process.platform === 'linux' && process.arch === 'ia32') {
+  assert.strictEqual(navigator.platform, 'Linux i686');
+} else if (process.platform === 'linux' && process.arch === 'x64') {
+  assert.strictEqual(navigator.platform, 'Linux x86_64');
+} else if (process.platform === 'freebsd') {
+  if (process.arch === 'ia32') {
+    assert.strictEqual(navigator.platform, 'FreeBSD i386');
+  } else if (process.arch === 'x64') {
+    assert.strictEqual(navigator.platform, 'FreeBSD amd64');
+  } else {
+    assert.strictEqual(navigator.platform, `FreeBSD ${process.arch}`);
+  }
+} else if (process.platform === 'openbsd') {
+  if (process.arch === 'ia32') {
+    assert.strictEqual(navigator.platform, 'OpenBSD i386');
+  } else if (process.arch === 'x64') {
+    assert.strictEqual(navigator.platform, 'OpenBSD amd64');
+  } else {
+    assert.strictEqual(navigator.platform, `OpenBSD ${process.arch}`);
+  }
+} else if (process.platform === 'sunos') {
+  if (process.arch === 'ia32') {
+    assert.strictEqual(navigator.platform, 'SunOS i86pc');
+  } else {
+    assert.strictEqual(navigator.platform, `SunOS ${process.arch}`);
+  }
+} else if (process.platform === 'aix') {
+  assert.strictEqual(navigator.platform, 'AIX');
+} else {
+  assert.strictEqual(navigator.platform, `${process.platform[0].toUpperCase()}${process.platform.slice(1)} ${process.arch}`);
+}
+
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'darwin' }), 'MacIntel');
+assert.strictEqual(getNavigatorPlatform({ arch: 'arm64', platform: 'darwin' }), 'MacIntel');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ia32', platform: 'linux' }), 'Linux i686');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'linux' }), 'Linux x86_64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'arm64', platform: 'linux' }), 'Linux arm64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ia32', platform: 'win32' }), 'Win32');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'win32' }), 'Win32');
+assert.strictEqual(getNavigatorPlatform({ arch: 'arm64', platform: 'win32' }), 'Win32');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ia32', platform: 'freebsd' }), 'FreeBSD i386');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'freebsd' }), 'FreeBSD amd64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'arm64', platform: 'freebsd' }), 'FreeBSD arm64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ia32', platform: 'openbsd' }), 'OpenBSD i386');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'openbsd' }), 'OpenBSD amd64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'arm64', platform: 'openbsd' }), 'OpenBSD arm64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ia32', platform: 'sunos' }), 'SunOS i86pc');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'sunos' }), 'SunOS x64');
+assert.strictEqual(getNavigatorPlatform({ arch: 'ppc', platform: 'aix' }), 'AIX');
+assert.strictEqual(getNavigatorPlatform({ arch: 'x64', platform: 'reactos' }), 'Reactos x64');