[Refactor] Use object-keys and is-arguments instead of a homegrow…

…n shim.

Leave re-exporting lib files behind to avoid a breaking change.

index.js

@@ -1,6 +1,6 @@
 var pSlice = Array.prototype.slice;
-var objectKeys = require('./lib/keys.js');
-var isArguments = require('./lib/is_arguments.js');
+var objectKeys = require('object-keys');
+var isArguments = require('is-arguments');
 
 var deepEqual = module.exports = function (actual, expected, opts) {
   if (!opts) opts = {};

lib/is_arguments.js

@@ -1,20 +1 @@
-var supportsArgumentsClass = (function(){
-  return Object.prototype.toString.call(arguments)
-})() == '[object Arguments]';
-
-exports = module.exports = supportsArgumentsClass ? supported : unsupported;
-
-exports.supported = supported;
-function supported(object) {
-  return Object.prototype.toString.call(object) == '[object Arguments]';
-};
-
-exports.unsupported = unsupported;
-function unsupported(object){
-  return object &&
-    typeof object == 'object' &&
-    typeof object.length == 'number' &&
-    Object.prototype.hasOwnProperty.call(object, 'callee') &&
-    !Object.prototype.propertyIsEnumerable.call(object, 'callee') ||
-    false;
-};
+module.exports = require('is-arguments');

lib/keys.js

@@ -1,9 +1 @@
-exports = module.exports = typeof Object.keys === 'function'
-  ? Object.keys : shim;
-
-exports.shim = shim;
-function shim (obj) {
-  var keys = [];
-  for (var key in obj) keys.push(key);
-  return keys;
-}
+module.exports = require('object-keys');

package.json

@@ -12,6 +12,10 @@
     "tests-only": "tape test/*.js",
     "test": "npm run tests-only"
   },
+  "dependencies": {
+    "is-arguments": "^1.0.4",
+    "object-keys": "^1.1.1"
+  },
   "devDependencies": {
     "tape": "^4.11.0"
   },

test/cmp.js

@@ -1,7 +1,5 @@
 var test = require('tape');
 var equal = require('../');
-var isArguments = require('../lib/is_arguments.js');
-var objectKeys = require('../lib/keys.js');
 
 test('equal', function (t) {
     t.ok(equal(
@@ -56,21 +54,6 @@ test('arguments class', function (t) {
     t.end();
 });
 
-test('test the arguments shim', function (t) {
-    t.ok(isArguments.supported((function(){return arguments})()));
-    t.notOk(isArguments.supported([1,2,3]));
-
-    t.ok(isArguments.unsupported((function(){return arguments})()));
-    t.notOk(isArguments.unsupported([1,2,3]));
-
-    t.end();
-});
-
-test('test the keys shim', function (t) {
-    t.deepEqual(objectKeys.shim({ a: 1, b : 2 }), [ 'a', 'b' ]);
-    t.end();
-});
-
 test('dates', function (t) {
     var d0 = new Date(1387585278000);
     var d1 = new Date('Fri Dec 20 2013 16:21:18 GMT-0800 (PST)');