Improve is-buffer detection and add stronger tests

README.md

@@ -1,40 +1,35 @@
-# is-buffer [![travis][travis-image]][travis-url] [![npm][npm-image]][npm-url] [![downloads][downloads-image]][downloads-url] [![javascript style guide][standard-image]][standard-url]
+# is-buffer [![npm][npm-image]][npm-url] [![downloads][downloads-image]][downloads-url] [![javascript style guide][standard-image]][standard-url]
 
-[travis-image]: https://img.shields.io/travis/feross/is-buffer/master.svg
-[travis-url]: https://travis-ci.org/feross/is-buffer
 [npm-image]: https://img.shields.io/npm/v/is-buffer.svg
 [npm-url]: https://npmjs.org/package/is-buffer
 [downloads-image]: https://img.shields.io/npm/dm/is-buffer.svg
 [downloads-url]: https://npmjs.org/package/is-buffer
 [standard-image]: https://img.shields.io/badge/code_style-standard-brightgreen.svg
 [standard-url]: https://standardjs.com
 
-#### Determine if an object is a [`Buffer`](http://nodejs.org/api/buffer.html) (including the [browserify Buffer](https://github.com/feross/buffer))
-
-[![saucelabs][saucelabs-image]][saucelabs-url]
-
-[saucelabs-image]: https://saucelabs.com/browser-matrix/is-buffer.svg
-[saucelabs-url]: https://saucelabs.com/u/is-buffer
+Determine if an object is a [`Buffer`](https://nodejs.org/api/buffer.html) (including browser-compatible Buffer implementations).
 
 ## Why not use `Buffer.isBuffer`?
 
-This module lets you check if an object is a `Buffer` without using `Buffer.isBuffer` (which includes the whole [buffer](https://github.com/feross/buffer) module in [browserify](http://browserify.org/)).
+This module provides a tiny compatibility wrapper for checking whether a value is a `Buffer`.
 
-It's future-proof and works in node too!
+- It prefers the native `Buffer.isBuffer` check when available.
+- It falls back to `constructor.isBuffer` for browser-compatible Buffer implementations.
+- It avoids throwing on malformed or spoofed objects.
 
-## install
+## Install
 
 ```bash
 npm install is-buffer
 ```
 
-## usage
+## Usage
 
 ```js
 var isBuffer = require('is-buffer')
 
-isBuffer(new Buffer(4)) // true
-isBuffer(Buffer.alloc(4)) //true
+isBuffer(Buffer.alloc(4)) // true
+isBuffer(Buffer.from([1, 2, 3])) // true
 
 isBuffer(undefined) // false
 isBuffer(null) // false
@@ -47,8 +42,13 @@ isBuffer(1.0) // false
 isBuffer('string') // false
 isBuffer({}) // false
 isBuffer(function foo () {}) // false
+isBuffer(new Uint8Array([1, 2, 3])) // false
 ```
 
-## license
+## Notes
+
+In modern Node.js projects, `Buffer.isBuffer` is often enough on its own. This package is most useful when you want a tiny wrapper that also tolerates browser-style Buffer implementations.
+
+## License
 
-MIT. Copyright (C) [Feross Aboukhadijeh](http://feross.org).
+MIT. Copyright (C) [Feross Aboukhadijeh](https://feross.org).

index.d.ts

@@ -1,2 +1,2 @@
-declare function isBuffer(obj: any): boolean
+declare function isBuffer(obj: unknown): boolean
 export = isBuffer

index.js

@@ -6,6 +6,21 @@
  */
 
 module.exports = function isBuffer (obj) {
-  return obj != null && obj.constructor != null &&
-    typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
+  if (typeof Buffer !== 'undefined' && typeof Buffer.isBuffer === 'function') {
+    return Buffer.isBuffer(obj)
+  }
+
+  if (obj == null || obj.constructor == null) {
+    return false
+  }
+
+  if (typeof obj.constructor.isBuffer !== 'function') {
+    return false
+  }
+
+  try {
+    return obj.constructor.isBuffer(obj)
+  } catch (_) {
+    return false
+  }
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "is-buffer",
-  "description": "Determine if an object is a Buffer",
+  "description": "Determine if an object is a Buffer with safe native fallback",
   "version": "2.0.5",
   "author": {
     "name": "Feross Aboukhadijeh",
@@ -17,7 +17,7 @@
     "tape": "^5.0.1"
   },
   "engines": {
-    "node": ">=4"
+    "node": ">=6"
   },
   "keywords": [
     "arraybuffer",
@@ -40,7 +40,7 @@
   "main": "index.js",
   "repository": {
     "type": "git",
-    "url": "git://github.com/feross/is-buffer.git"
+    "url": "https://github.com/feross/is-buffer.git"
   },
   "scripts": {
     "test": "standard && npm run test-node && npm run test-browser",

test/basic.js

@@ -19,6 +19,9 @@ test('is-buffer', function (t) {
   t.equal(isBuffer(function foo () {}), false, 'function foo () {}')
   t.equal(isBuffer({ isBuffer: null }), false, '{ isBuffer: null }')
   t.equal(isBuffer({ isBuffer: function () { throw new Error() } }), false, '{ isBuffer: function () { throw new Error() } }')
+  t.equal(isBuffer(new Uint8Array([1, 2, 3])), false, 'Uint8Array')
+  t.equal(isBuffer(new ArrayBuffer(8)), false, 'ArrayBuffer')
+  t.equal(isBuffer({ constructor: { isBuffer: function () { return true } } }), false, 'fake constructor.isBuffer')
 
   t.end()
 })