[Refactor] use is-array-buffer package

Author: ljharb

.eslintrc

@@ -15,6 +15,11 @@
     "no-magic-numbers": [2, { "ignore": [0, 1] }],
   },
 
+  "globals": {
+    "Int8Array": false,
+    "Uint8Array": false,
+  },
+
   "overrides": [
     {
       "files": "example/**",

index.js

@@ -15,20 +15,10 @@ var getIterator = require('es-get-iterator');
 var getSideChannel = require('side-channel');
 var whichTypedArray = require('which-typed-array');
 var assign = require('object.assign');
+var isArrayBuffer = require('is-array-buffer');
 
-// TODO: use extracted package
-var byteLength = callBound('ArrayBuffer.prototype.byteLength', true);
-function isArrayBuffer(buffer) {
-  if (!buffer || typeof buffer !== 'object' || !byteLength) {
-    return false;
-  }
-  try {
-    byteLength(buffer);
-    return true;
-  } catch (e) {
-    return false;
-  }
-}
+var byteLength = callBound('%ArrayBuffer.prototype.byteLength%', true)
+	|| function byteLength(ab) { return ab.byteLength; }; // in node < 0.11, byteLength is an own nonconfigurable property
 
 var $getTime = callBound('Date.prototype.getTime');
 var gPO = Object.getPrototypeOf;
@@ -342,7 +332,6 @@ function objEquiv(a, b, opts, channel) {
   if (aIsArrayBuffer !== bIsArrayBuffer) { return false; }
   if (aIsArrayBuffer || bIsArrayBuffer) { // && would work too, because both are true or both false here
     if (byteLength(a) !== byteLength(b)) { return false; }
-    /* global Uint8Array */
     return typeof Uint8Array === 'function' && internalDeepEqual(new Uint8Array(a), new Uint8Array(b), opts, channel);
   }
 

package.json

@@ -35,6 +35,7 @@
     "es-get-iterator": "^1.1.2",
     "get-intrinsic": "^1.1.3",
     "is-arguments": "^1.1.1",
+    "is-array-buffer": "^3.0.1",
     "is-date-object": "^1.0.5",
     "is-regex": "^1.1.4",
     "isarray": "^2.0.5",

test/cmp.js

@@ -1159,7 +1159,6 @@ test('TypedArrays', { skip: !hasTypedArrays }, function (t) {
   });
 
   t.test('one TypedArray faking as another', { skip: !hasDunderProto }, function (st) {
-    /* globals Uint8Array, Int8Array */
     var a = new Uint8Array(10);
     var b = tag(new Int8Array(10), 'Uint8Array');
     b.__proto__ = Uint8Array.prototype; // eslint-disable-line no-proto
@@ -1218,6 +1217,7 @@ test('TypedArrays', { skip: !hasTypedArrays }, function (t) {
       false
     );
 
+    // node < 0.11 has a nonconfigurable own byteLength property
     t.test('lies about byteLength', { skip: !('byteLength' in ArrayBuffer.prototype) }, function (s2t) {
       var empty4 = new ArrayBuffer(4);
       var empty6 = new ArrayBuffer(6);